-----------------------------------------------------------------------SUMMARY: 90-93 Q45 chain guide repair (hints, suggestions, procedures):DISCLAIMER: I have not done this task (I merely read what others said).ACTION: Please review for missing steps or incorrect statements below.

NOTE: If this is anything like the last oil pan R&R, it will sound extensive but actually it will be missing key steps and procedures.-----------------------------------------------------------------------1. Forumulate a basic overview understanding of the situation at hand:...The whole chain is under tension; but we use tension & slack terminology.The crankshaft pulls on the straight leg of the chain (the tension side).Then (terminologically) the curved leg is "pushed" (i.e., the slack side)....The guides that were redesigned are the tension-side (straight) guides. A new plastic tension guide sits on top of a new metal tension guide.These two guides replace one guide (using longer bolts than original)....Light blue-gray RTV around the timing cover & oilpan is likely factory.Red RTV would most likely indicate the cover was removed at one point.The passenger side slack guide can be viewed by removing an engine porthole....The slack-side (curved) guides don't generally fail & were not redesigned.The guides on the driver's side are those that most often fail.So, that would make the driver side tension guide the main failure item....The original design used 2 guides per chain (slack-side & tension-side).The new design uses three guides per chain (2 for 1 on the tension guide).The slack-side guides were metal originally so new is almost identical....The straight leg has enough tension it almost doesn't need a guide.Even if the tension guide fails, the engine may run fine for a long while. The plastic pieces may wedge between chain and sprocket....The timing cover may crack (leaking oil profusely).The chain can break.The chain can skip a tooth (or two or three)....The main danger is a chain jumping a tooth causing valve timing changes.Each cam gear tooth is 10 degrees (each crank gear tooth is 20 degrees). One crank tooth or 2 cam teeth is the ragged edge of exhaust valve contact....The second danger is pieces lodging under the chain (perhaps breaking it).Chain guide slop may also cause engine-cover oil-chain "ears" to break off.That loose "ear" lodges in the oil pump sprocket & cracks the timing cover....Broken pieces that fall into the oil pan are also a potential problem.Large pieces (which grind ever smaller) may clog (starve) the oil pickup.Smaller pieces (grinding ever smaller) may score the oil pump vanes....There are 2 oil chain guides, but 1 wears faster than the other. The slack-side oil pump guide doesn't have a tensioner. It's just set in place and has to be manually adjusted (i.e., replaced). ...Generally you do not have to replace the timing chains.If you replace timing chains, it will take twice as long to do the job.If you replace timing chains, the valve covers will have to come off....The toughest chainguide step is R&R of the 270 ftlb crankshaft-pulley bolt.Do NOT put a chain wrench on the pulley & then tap the starter switch. You may put a wrench on the bolt resting on something solid & tap the starter....Byron apparently also takes the pulley off the power steering pump.Most replace the oil pump but there isn't much evidence to show it's needed.It would be interesting to test oil pressure before & after oilpan cleanup....Q: What is missing or incorrect from this ad hoc summary?-----------------------------------------------------------------------2. Read how to perform the job based on others' experience: ----------------------------------------------------------- Factory Shop Manual, Engine Mechanical section: Note: I could barely understand the FSM so correct as needed. ----------------------------------------------------------- Photographic summary of a chain guide & oil pan replacement: http://www.q45.org/guidereplacement.html (www.q45.org/guidereplacement.html) zerothread?id=77266 (forums.nicoclub.com/zerothread?id=77266) ----------------------------------------------------------- Photo of tension side guides and slack side guides: zerothread?id=53660 (forums.nicoclub.com/zerothread?id=53660) zerothread?id=53660 (forums.nicoclub.com/zerothread?id=53660) ----------------------------------------------------------- Timing chain parts list: zerothread?id=15226 (forums.nicoclub.com/zerothread?id=15226) zerothread?id=13851 (forums.nicoclub.com/zerothread?id=13851) ----------------------------------------------------------- Chain Guide step by step & Roller Chain Engineering Data: http://nicoclub.com/zerothread?id=1632 (nicoclub.com/zerothread?id=1632) http://www.ustsubaki.com/chainguide.html (www.ustsubaki.com/chainguide.html) ----------------------------------------------------------- Checking chain guides: zerothread?id=7058 (forums.nicoclub.com/zerothread?id=7058) zerothread?id=12551 (forums.nicoclub.com/zerothread?id=12551) ----------------------------------------------------------- Replacing chain guides: zerothread?id=15861 (forums.nicoclub.com/zerothread?id=15861) zerothread?id=48852 (forums.nicoclub.com/zerothread?id=48852) ----------------------------------------------------------- Supporting the engine & tension-side chain guide information: zerothread?id=27044 (forums.nicoclub.com/zerothread?id=27044) zerothread?id=92067 (forums.nicoclub.com/zerothread?id=92067) ----------------------------------------------------------- Aligning marks for timing chain guide replacement: zerothread?id=71463 (forums.nicoclub.com/zerothread?id=71463) zerothread?id=710 (forums.nicoclub.com/zerothread?id=710) ----------------------------------------------------------- Checking for new chain guides: zerothread?id=15648 (forums.nicoclub.com/zerothread?id=15648) zerothread?id=12941 (forums.nicoclub.com/zerothread?id=12941) ----------------------------------------------------------- Chain guide replacement hints: zerothread?id=26454 (forums.nicoclub.com/zerothread?id=26454) zerothread?id=28462 (forums.nicoclub.com/zerothread?id=28462) ----------------------------------------------------------- Chain guide noise & broken timing chain cover debug steps: zerothread?id=16281 (forums.nicoclub.com/zerothread?id=16281) zerothread?id=46708 (forums.nicoclub.com/zerothread?id=46708) -----------------------------------------------------------Q: Are there any better references?-----------------------------------------------------------------------3. Obtain requisite parts from Joe of Scottsdale Infiniti or elsewhere: http://www.EverythingNissan.com 888-216-5328 - 1x 13510-60U00 - front cover seal - 2x 13270-60U00 - valve cover gaskets (if valve cover is removed) - 4x 11051-60U04 - cam end seals (if the valve cover is removed) - 1x 13091-60U01 - guide (tension RH) - 1x 13091-60U11 - guide (tension LH) - 1x 13070-60U03 - chain tensioner (RH) - 1x 13070-60U12 - chain tensioner (LH) - 2x 13085-60U01 - chain guide (tensioner guide?) - 2x 13085-60U11 - chain guide - 2x 13094-60U00 - guide bolts - 2x 01121-04711 - guide bolts - 4x 13075-60U02 - tensioner bolts - 1x 13079-60U01 - tensioner gasket (LH) - 1x 15041-60U00 - oil pump chain (highly recommended) - 1x 15073-60U00 - oil pump chain guide - 1x 15073-60U10 - oil pump chain guide - 1x 15072-60U00 - bracket oil pump - 1x 15044-60U00 - crank/oil sprocket - 1x 15043-60U00 - crank/timing sprocket - 2x 13021-60U00 - crank/cam sprockets (if warranted) - 2x 13028-60U00 - timing chains (if warranted)

Q: Which parts are mandatory or recommended, & which are merely optional?-----------------------------------------------------------------------4. Line up the necessary shop tools: - Garage tools (jack/stands or ramps, creeper, etc) - Common metric sockets (8, 10, 12, 14, 15, 17, 19mm) - You will use the 10mm the most by far so have a few types on hand. - Large crank bolt socket (30 or 31mm) - Ratchets and 10 mm wrenches. - 18" breaker bar and an extension pipe. - A 300 ft-lb torque wrench (maybe). - A large puller (Sears has them for about $30) - A 5mm allen socket (do not use an allen wrench); this is CRITICAL. - A chain wrench long enough to wrap around the main pulley. - That chain wrench must have a 3-foot handle (or a 3-foot pipe) - An old ribbed belt sufficient to wrap around the crank pulley. - Other common shop tools--pliers, vise grips, magnetic tool pickups, etc. - RTV (1 tube of Permatex Blue will be plenty). - Feeler gauges (1mm, 0.04 inches) for chain-to-guide distance.

Q: What suggested tools are missing from this list?-----------------------------------------------------------------------5. Overview of chain guide replacement steps (no chains = 10 hours): - Inspect lower valve cover abutment with engine for RTV color - Or pull the front-most oil pan bolt to check the RTV in the bolt hole. - If it's light gray/blue, then it's most likely still factory sealed. - Red RTV (most common) is not factory (according to most accounts). - This isn't definitive; but it's a circumstantial hint nonetheless. - Remove all plastic trim pieces to expose radiator and cover. - Drain coolant and remove radiator. - Remove all belts. - Remove all belt tensioners. - Remove metal bracket on PS fluid pump covering front cover. - Remove coolant hose running across front cover. - Align the pulley to TDC (How? There are six crankshaft-pully notches). - What do we align the left-most (facing engine) crank-pulley notch to? - Remove crank pulley main bolt with a wrench on the nut. - Use a chain wrench to immobilize the crank pully while you tug. - You may need to put an old belt section to cover the pulley ribs. - This helps give the chain wrench more bite & may protect the ribs too. - If you can run the car, use just the wrench & tap the starter. - This (if done in the right direction) may loosen the crank pulley bolt. - Leave the 5 small balance bolts & allen-head bolt on the crank pulley. - Pull off the unbolted crank pulley with a 3-jaw puller or equivalent. - Remove the front lower timing chain cover screws. - Note there four oil pan bolts holding the lower timing chain cover. - Note the upper timing chain covers may remain on the engine. - Remove the lower front cover. - Note the 6 different lengths and 32 bolt holes (keep track). - Pry at the bottom corner of the cover, near the alternator - Also pry just below the water pump. - May need to remove the pump (5 bolts and RTV) to get to pry point. - Try to pry/pull as evenly as possible. - Don't damage the solid gasket between lower & upper timing covers. - Immediately after removing the cover, block the oil pan with towels. - Inspect all timing chains for cracks or excessive wear indications. - Locate the TDC dimple below a tooth in the crank sprocket. - Just above that dimpled tooth should be a timing chain GOLD LINK. - Remove the oil pump chain, guide and sprocket (which is not keyed). - Note the oil pump crankshaft sproket has a key cut. - This oil pump crank sprocket keyway isn't used to hold it in place. - Compression/friction of the 270 foot pound crankshaft bolt holds it. - This oil pump sprocket keyway is there only to put it on the crankshaft. - Cinch timing chains tightly to prevent jumping a sprocket tooth. - This is the most critical step (most folks use tie wraps) - Remove the old chain guides (don't let the chains loosen). - Re-cinch chains, if needed, to be safe (do we use a 1mm feeler gauge?). - Use a 5mm allen socket to remove the old tensioners (very tight) - Install new tensioners and guides (don't use a 5mm allen wrench) - Measure with a feeler gauge 1mm distance between upper guides & chain. - Make sure there is no gunk clogging the tensioner oil ports. - Use "BG Quick Clean for Engines" (if necessary) to unclog HLA passages. - Try to fish out any pieces left in the oil pan (or vacuum them out). - Install new oil pump chain, guide and sprocket. - Turn the crankshaft slowly by hand before putting covers on. - If anything binds, now is the time to find out. - Clean the mating surfaces of the cover and degrease - Don't bend the solid gasket above the cover as you install the cover. - Note there is no RTV between the timing cover and its solid gasket. - Apply fresh RTV and install cover with all bolts. - Torque all cover bolt to spec where possible (see FSM). - Torque the crankshaft pulley bolt to 270 foot pounds. - 90 lbs of force on a 3-ft bar will do if you don't have a torque wrench. - Install everything in the reverse order of removal - Fill up coolant - Fill up the oil - Turn main pully two full turns to spread oil around the engine. - You'll feel & hear the compresson cycles; hopefully nothing else. - Torque up the main bolt to 270 ft-lbs before replacing the belts. - Two strong guys are probably best for this step. - Pull the fuel pump fuse and crank the engine to spread some more oil. - Replace the fuel pump fuse. - Crank engine & turn off imediately 5 or 10 [sometimes 20] times. - It may sound like the engine is going to explode for a minute. - HLA & tensioners need to bleed air admitted when you changed them. - The noise should suddenly go away after a few minutes running. - Run [multiple] warm/hot power balances - Make sure every cylinder drop is no more than 25 rpm variance. - If you have not dropped the oil pan, run an oil pressure check. - This might tell you if the oil pickup is clogged with guide debris.

Q: What steps are missing or incorrect or misleading in this summary?-----------------------------------------------------------------------6. QUESTIONS: - Q: Which specific parts in the parts list above are mandatory? - Q: What are the correct names of the confusing front engine covers? - Q: How do you set the crank pulley to #1 cylinder compression stroke TDC? - Q: Does RTV go only on one side of the timing cover gasket material? - Q: How do you do a "power balance" as recommended by q45tech? - Q: I see timing marks on the pulley; where do they line up on the block? - Q: Should the transmission cooler be serviced at the same time? - Q: What's a CAS mark? - Q: What's an HLA passage?-----------------------------------------------------------------------7. IMAGES: Note: All images courtesy of DAEDALUS in NICO post:zerothread?id=92729

The tension-side guides are the ones that fail. Driver's side fails usually fails first; probably because the passenger-side is closer to vertical.

Collection of parts for a chain guide job.

Original, failure-prone guide.

Close-up of new guide installed. Note that it's a 2-piece design, nylon-clad metal piece on one side and a thick beefy nylon piece on the other side.-----------------------------------------------------------------------

The passenger side tensioner has a small hook to hold it compressed that makes that side much easier. There is no timing cover gasket, so I don't understand the question on RTV on one side of it. The power balance test is done with a Consult on a fully assembled and running engine, no application to this process. I didn't worry about the timing marks, if the chain doesn't slip they aren't a factor, if it does you start from scratch anyway. I replaced all the guides, including the oil pump guides and the front crank seal. You may want to include new tensioners with your higher mileage and broken guide pieces in the system. The longer guide bolts are also mandatory.

It is also common practice to replace the oil pump chain. It should have stretched substantially by now.

Heath

- Align the pulley to TDC (How? There are six crankshaft-pully notches). - What do we align the left-most (facing engine) crank-pulley notch to?There is a TDC mark on the pulley, and a dowel on the front timing cover. - Turn the crankshaft slowly by hand before putting covers on. - If anything binds, now is the time to find out. - Don't bend the solid gasket above the cover as you install the cover.Not real difficult, but very critical. If the oil pan is on, you need to shoehorn the cover in between the pan and the upper timing covers without messing up the head gasket (flush with the upper covers). If you bungle the head gasket, not sure what would be a good alternative. - Note there is no RTV between the timing cover and its solid gasket. There is none installed at the factory, but it may be a good idea to add some on the reseal. I think Heath said Byron at T3 does. The headgasket won't seal as well after the cover's been removed.

-----------------------------------------------------------------------6. QUESTIONS: - Q: What are the correct names of the confusing front engine covers?There are 3 front timing covers, 1 lower and 2 upper. - Q: How do you set the crank pulley to #1 cylinder compression stroke TDC?TDC is set as above with the pulley mark. Compression stroke is determined from direction of notch on front of CAS. - Q: Does RTV go only on one side of the timing cover gasket material?Not sure. You could put it on both, but it would be very thin. - Q: How do you do a "power balance" as recommended by q45tech?Consult - Q: I see timing marks on the pulley; where do they line up on the block?Dowel pin at about the 10:30 position. - Q: Should the transmission cooler be serviced at the same time?Serviced? The factory heat exchanger? - Q: What's a CAS mark?A mark on the CAS under the cover--tells what stroke #1 is on. - Q: What's an HLA passage?Hydraulic Lash Adjuster oil passage--small tunnels for passing pressurized oil through the engine for the HLAs in the head. Hydraulics don't need adjusting and quiet the valves.-----------------------------------------------------------------------

Here is my list: Qty. Ea. Total:13070-60U03 ASR 1 TNSNR CHAIN V02D 3 49.90 49.9013070-60U12 ASR 1 TENS CHAIN V02D 0 49.90 49.9013075-60U02 ASR 4 BOLT-TENSIONER V02D 5 1.40 5.6013085-60U01 ASR 2 GUIDE-CHAIN,TENSI J06 3 7.19 14.3813085-60U11 ASR 2 GUIDE-CHAIN,TENSI V02D 1 7.19 14.3813091-60U01 ASR 1 GUIDE CHAIN J06 1 54.43 54.4313091-60U11 ASR 1 GUIDE CHAIN J06 1 54.43 54.4313510-60U00 ASR 1 SEAL-OIL CRANKSHA BC2B 5 5.34 5.3415041-60U00 ASR 1 CHAIN-OIL PUMP DR V02H 0 37.01 37.0115073-60U00 ASR 1 GUIDE-CHAIN V02H 0 6.66 6.6615073-60U10 ASR 1 GUIDE-CHAIN V02H 0 4 0.48 40.48999MP-A7007P 1 GASKET SILICONE L BCNTR 9 14.99 14.99

This is what we sell & consider a complete kit.-Joe

jtesensky wrote:This is what we sell & consider a complete Q45 chain-guide kit.

For the next DIY to begin where we currently stand, here is jtensensky's newly recommended chain-guide R&R list merged with an older PalmerWMD's set of additional suggested components and an annotated FSM exploded diagram.

Note: Both Joe's & Fred's list seemed to show all guides as tension, which I don't think can be correct; so, I guessed a bit at the part descriptions (as indicated below by the liberal use of the question mark).

Recommended: 13085-60U01 (2x) - Chain guides (tension?, base?) $7.19 each = $14.38 13085-60U11 (2x) - Chain guides (tension?, inserts?) $7.19 each = $14.38 13091-60U01 (1x) - Chain guide (slack?, right hand side) = $54.43 13091-60U11 (1x) - Chain guide (slack?, left hand side) = $54.43 --- 13070-60U03 (1x) - Chain tensioner (right hand side) = $49.90 13070-60U12 (1x) - Chain tensioner (left hand side) = $49.90 13075-60U02 (4x) - Bolts (tensioner) $1.40 each = $5.60 --- 15041-60U00 (1x) - Oil pump chain = $37.01 15073-60U10 (1x) - Oil pump chain guide (tension?) = $40.48 15073-60U00 (1x) - Oil pump chain guide (slack?) = $6.66 --- 13510-60U00 (1x) - Front cover crankshaft seal = $5.34 999MP-A7007P(1x) - Silicone gasket material (RTV red, 5 ounce tube) = $14.99 ---Optional: 13028-60U00 (2x) - timing chains (if warranted) 13021-60U00 (2x) - crank/cam sprockets (if warranted) 15044-60U00 (1x) - crank/oil sprocket 15043-60U00 (1x) - crank/timing sprocket 13079-60U01 (1x) - tensioner gasket (LH) 13270-60U00 (2x) - valve cover gaskets (if valve cover is removed) 11051-60U04 (4x) - cam end seals (if the valve cover is removed) 15072-60U00 (1x) - bracket oil pump 13094-60U00 (2x) - bolts

Please correct where I err so others always benefit.

I don't think the tensioner gasket should be optional. Too much risk of an oil leak from re-using the old one.

DAEDALUS wrote:I don't think the tensioner gasket should be optional.

Sounds reasonable. We'll have to ask Joe in the morning why it's not part of his (otherwise complete) chain-guide-retrofit kit.

Since there are two tensioners (presumably one for each timing chain but none for the shorter oil-pump chain), are you suggesting we replace TWO tensioner gaskets?

P.S. I don't see any gaskets in the 90 FSM diagram SEM871C on page EM-14; are they simply rubber 0-rings?

You have the chain tensioner callout in a blue box. Just above it is the gasket, only on the driver's side. It's paper, goes between the tensioner mating flange and the cover.

DAEDALUS wrote:... chain tensioner gasket ... only on the driver's side.

Oh, there it is. I didn't know what that was nor that there was only one of them (and it's not labelled so you just gotta know). Now we know (see photo below). I'll call Joe to recommend he update his kit (unless someone says otherwise in this forum).

P.S. On aligning the left-most crank-shaft-pulley notch with the lower timing cover 10:30 dowel to #1 cylinder TDC compression stroke ... what do the letters CAS stand for?

tangalora wrote:
Oh, there it is. I didn't know what that was nor that there was only one of them (and it's not labelled so you just gotta know). Now we know (see photo below). I'll call Joe to recommend he update his kit (unless someone says otherwise in this forum).

P.S. On aligning the left-most crank-shaft-pulley notch with the lower timing cover 10:30 dowel to #1 cylinder TDC compression stroke ... what do the letters CAS stand for?

Pictorially the gasket is incorrect, as it's under the tensioner, not above it. Probably a drafting error that left it out, so they just drew it in above.

CAS = crank angle sensor. It's the component bolted to the front of the driver-side head in front of the exhaust camshaft (also in the pic).

DAEDALUS wrote:Probably a drafting error ...

Oh. OK. Now it makes more sense.I've seen worse Q45 drafting errors worse, (e.g., rear brake shims on the 90 to 93 Q45 are all drawn in the wrong location (http://www.nicoclub.com/zerothread?id=47476).

Seems like this driver-side tensioner paper gasket would be an inexpensive & easy-to-replace component in a chain-guide R&R job.I wonder why Joe left it out. I'll ask when I get a chance.

Quote »CAS = crank angle sensor[/quote]Oh. (sheepish look on my face). I see it in the exploded diagram now.Near the bottom, presumably inside the lower timing cover at the crankshaft.

DAEDALUS wrote:There is a TDC mark on the pulley, and a dowel on the front timing cover.

Forgive me if this is a basic question, but, the manual simply shows the picture below so I'm still just a tad confused on the TDC setup (why do we bother if the chains stay on anyway?) ...

Do we simply align the left-most (of the six) crankshaft-pulley notches to this lower-timing-chain-cover dowel before pulling off the lower timing chain cover?

Does that manual crank-pully notch/dowel alignment, all by itself, assure us of placing the driver side front-most #1 cylinder at top dead center of the compression stroke (without having to pull a plug to feel the pressure nor screw in a dial gauge to determine the top of the stroke)?

That is, do we really need to perform this step and how do we know that's gonna be the compression stroke and not the venting stroke?

The CAS is bolted toward the top, half over the valve cover and half over the upper timing cover (see the half-circle cutouts for it in the covers?). It protrudes through both sides of the covers--some inside getting oily and some outside, with harnesses attached.

Getting to TDC is more important when you're removing the chains. Always good to be at TDC as a general shop rule when taking apart the valvetrain so you know where you are when you're putting stuff back. I believe 911/Q45 is right it's not needed for doing the guides, but it wouldn't hurt if you choose to. Can't find TDC without the front timing cover.

You have to look at the CAS to know if #1 is on compression or exhaust, then you fine-tune the postion with the marks on the pulley and cover. The cas spins 1/2 as fast as the crank. There's a mark on the face under the plastic cover. If it's on the left side, it's compression. Right side means exhaust.

DAEDALUS wrote:You have to look at the CAS to know if #1 is on compression or exhaust, then you fine-tune the postion with the marks on the pulley and cover. If it's on the left side, it's compression. Right side means exhaust.

Hmmmm ... Sorry to be so thick headed. If God doubled the number of neurons in my brain, I'd have a synapse up there. Anyway, I think you've explained setting compression TDC as well as it can be done. My problem I think is I've never seen the CAS nor have I looked closely at the lower timing cover so I'll take a look at the actual crank angle sensor when daylight arrives. Hopefully I'll see these marks you're so diligently trying to explain to us.

Meanwhile, I'll merely point out that the sum total of FSM help I could find on setting #1 cylinder compression TDC is the following two mostly un-annotated diagrams and the single instruction (for both diagrams) of: "Set #1 pistion at TDC on its compression stroke"without anything (that I could find) telling us how to do it.

If I didn't know about the CAS, I'd have pulled as many plugs as possible (to lower compression resistance), and then tried to rotate the engine (I assume in the clockwise direction facing the engine) a few times until I figured out which of the pull-push-pow-puey strokes was the compression stroke.

Then, I'd have tried (maybe) to screw my brake-runout dial gauge (somehow) into the driver-side front-most #1 cylinder spark plug hole and again slowly spin the engine until the gauge rose to its highest point (i.e., TDC).

But, on the Q45, it looks like there's no need for those shenanigans; I think figuring out the CAS arrangement in daylight will be easier.

Pull the plastic cover. You'll see the mark.

DAEDALUS wrote:Pull the plastic cover. You'll see the mark.

Geez! That little teeny tiny dot? Only now do I see it on the FSM diagram (plain as the nose on my face); but, without you pointing it out, I would never have found it in those miniscule factory directions. How does a DIY ever do the right job the first time without advice from folks like you on Nico???

Whew! I'm not sure what the "plastic cover" is, but I suspect I'll see it when I remove the aluminum lower timing-chain cover over it (I guess).

Speaking of following expert Nico advice, Scottsdale Infiniti emphatically agrees with you; therefore they will now add the tensioner gasket to their chain-guide engineering kit so everyone in the future will have it when they buy Joe's latest kit:13079-60U01 (1x) - Chain tensioner gasket (driver side) = $0.55

This is a classic Nico example of folks working together for a common cause to better the lot of the next member in the same boat!

The plastic cover and CAS are located above the timing covers. Look near the airbox on the top side on the left (driver's) side of the engine. Here's a picture.... Ignore the markings - you shouldn't need to adjust your timing.



Heath
Modified by Q451990 at 6:17 PM 12/10/2004

[QUOTE=Q451990] Look near the airbox on the top side on the left (driver's) side of the engine. Here's a picture .../QUOTE]

OH. (slaps forehead) ... Now I get it. Finally. Sorry it took me so long.

I'm a dummy. Up until now, I kept looking at the two circular things at the top front of each bank of (what I think is the) head. Now that I realize where the (one) crank angle sensor lies, I now see it (for the first time) on the engine (about 5 inches above the oil filter).

A lot of the prior puzzling conversations now begin to make sense. Thanks to everyone for perservering and not giving up on me.Sorry I'm such a numbskull sometimes.I just never had to deal with the CAS before.

I had never even thought about how the engine figured out where the #1 piston was in order to electronically regulate when to emit the voltage controlling things such as spark & fuel injection pulses.

It seems the two orbs I thought were crank angle sensors are actually the two Timing Control Solonoid Valves shown on page EF & EC 17 of the 1990 Q45 FSM (diagram SEF482J). These two solonoid valves apparently control the oil pressure used to regulate intake valve dwell or something like that (based solely on my interpretation of the description in the 90 FSM).

I'm just now realizing the dot we've been pointing to is apparently on a disc which is part of the BACKUP angle sensing unit of the CAS which operates magnetically, probably by detecting inductive changes as the grooved rotor periodically presents more and less metal to the rectangular block in the 9 o'clock position in the SEM884C diagram previously posted (which is probably just a backup Hall Effect sensor).

It seems, underneath that 9'oclock backup "sub-crank angle sensor", deeper inside the CAS, is apparently the primary calibrated disc with 360 by 1 degree plus 8 by 90 degree slits modulating LED light emitted from one side of the disk picked up by a photodiode on the other side forming constant-width 1 degree short pulses and 8 successively longer pulses ticking off the 90 degree increments of the pull-push-pow-puey 720 degree 4-stroke cycle.

As you stated, we don't specifically have to even think about this if we don't move the timing chain relative positions ... but it seems like a good idea (just in case a chain has cracks or otherwise has to be replaced). Do I simply rotate the engine using a wrench on the crank bolt to line the #1piston to compression TDC?

This next question is related more to spark timing than valve timing, but, I'm curious ... If I were to put a timing light on this VH45DE engine, I could shine it on the crankshaft pulley after whiting-out the left-most TDC notch ... but, since there is no corresponding conventional fixed gradated plate to compare 17 degrees BTDC as the notch rotates past it, that leaves me two fundamental spark-timing questions I've always wondered about: a) How would I clamp the pickup of the timing light onto the #1 spark wire? b) How would I know the degrees of advance even if I could?

Or, do we just read actual spark timing degrees before TDC some other way?

This, by the way, is a closeup of the "cover" of the crank angle sensor (CAS) unit found (surprisingly enough ) exactly where Heath & Robert said it would be.

I post this closeup for the next person who may be (at first) as clueless as I.

Please see Heath's photo for the relative location of this CAS on the Q45 engine. The puzzle pieces are starting to assemble themselves.

I'm glad my picture helped. Don't worry about asking questions or feeling dumb - you have bitten off a lot more than I would ever try on my Q. I can't wait to see pictures of it all back together and hear stories of your first drive in months!

Heath

Besides the two CAS-dot-to-hall-effect-transducer compression-stroke alignment set points listed above, another puzzling (to me) set of alignment marks was the crankshaft-pulley-to-engine-block alignment for #1 piston TDC.

Here, for the record, for others to benefit from, is a photo of the DOWEL previously mentioned next to the crankshaft pulley. We need (apparently) to align the left-most pulley notch (not shown in the photo) with this dowel.

With that in mind, given this puzzlingly over simplified (to me) 90 FSM instruction:Set No. 1 piston at T.D.C. on the compression stroke.here is my slightly more detailed interpretation:a) With a chain wrench on the crank pulley, turn the crankshaft ...(I think clockwise) ...b) Until the CAS dowel lines up with the flat edge of the hall effect transducer (at the 9 o'clock position) ...c) And the left-most of six crankshaft pulley notches lines up with the dowel (at about 10:30 on the lower valve cover).

BTW, am I correct in assuming #1 piston is the driver side front-most cylinder and the engine turns clockwise (facing it)?

Q451990 wrote:I'm glad my picture helped ... I can't wait to see pictures of it all back together

Boy, did it. I can't believe that I was looking in all the wrong places for that CAS. I wouldn't have been able to comprehend the steps without those valuable hints from you and DAEDALUS in the last few precious posts. Thanks!

Regarding reassembly ... if documentation is 20% of the effort; figuring out how to do it is in the first place is another 20%; then of the 80% for R&R, the removal probably takes 60% ... leaving an entire 40% to torque it all back together correctly (especially after months in mothballs).

For example, I hesitate to even think of forcing that alternator to get back in line. And, I'm sure I'll forget where some parts go. I did hedge my bets by putting all bolts and nuts immediately back in place at the first moment I could whenever I removed a part. I'd never remember where they go otherwise.

BTW, for the next person, here's a shot of the difference between what appears to be factory blue/gray RTV on the timing covers and replacement red on the water pump gasket. Factory blue/gray implies the covers have never been off and I believe we can infer from the red RTV that the water pump was replaced at some point in time.

tangalora wrote:... if documentation is 20% of the effort; figuring out how to do it is in the first place is another 20%; then of the 80% for R&R, the removal probably takes 60% ... leaving an entire 40% to torque it all back together correctly (especially after months in mothballs).

Ooops. Math boo boo. I guess big jobs are 120% efforts!

Can you confirm only the lower timing chain cover needs be removed?If the upper timing chain covers remain, then can I leave the black plastic covers on the upper timing cover intact?Also, does anyone do this job without removing the radiator?The radiator only seems to gain us a couple of inches.

Also, since I have to buy the socket & box wrench, can someone confirm the crankshaft bolt head size (is it 30 mm?).

I guess I'll know all of this once I receive the new kit from Joe & I start anew.I'm just on the first 20% (figuring out how to do the job) right now.

a) How would I clamp the pickup of the timing light onto the #1 spark wire? b) How would I know the degrees of advance even if I could?zerothread?id=70429This method works fine for simple and advanced DIS timing lights. Won't work very well with the dial-back feature on the more basic units. For them you need to insert a spark plug wire between the plug and the coil for the inductive clamp.BTW, am I correct in assuming #1 piston is the driver side front-most cylinder and the engine turns clockwise (facing it)?Yes.Can you confirm only the lower timing chain cover needs be removed?Yes.If the upper timing chain covers remain, then can I leave the black plastic covers on the upper timing cover intact?Probably not. Other things need to be out of your way.Also, does anyone do this job without removing the radiator?The radiator only seems to gain us a couple of inches.A couple inches is a lot when working in cramped quarters. The clearance gained is second to the minimized risk of damage to the radiator. The fins are thinner than paper and will bend at the slightest incidental contact. Remove the radiator--makes installation of the tranny cooler easier too.

I'm pretty sure the factory used red RTV on the water pump. Every Q I've seen has red RTV there. The red stuff conducts heat better than the others, though I would think the difference there would be negligible. It is the water pump after all.

DAEDALUS wrote:I'm pretty sure the factory used red RTV on the water pump.[/color]

I obviously misinterpreted when I reviewed the previous threads on the topic. I now realize that red RTV on the timing chain covers implies non factory; but that we can't infer non-factory from red RTV anywhere else. Thanks. I stand corrected and (now) better informed.

I'm still confused on the timing-light issue - but - since that's a totally unrelated topic, I'll defer the mystery to another time & another thread.

I'll go shoppin' today for Christmas gifts for the family ... and ... while I'm at the mall ... I'll pick up a coupla' 30mm (or so) crank bolt wrenches, a gear puller gizmo, and a chain-strap-wrench-thingey from Sears.

I did my guides without removing the radiator, but agree with Daedalus that removal is better. I'll bet that the original water pump RTV was blue, but none of us has ever seen an original one. Even mine had been replaced when I got it with 25K miles.

Here are a few more pics from the guide replacement at T3. This is after the new guides were in place. I'm not sure if you'll see anything different than the pics. that are already in the thread - but maybe something will be helpful. Remember that we were re-sealing my rocker covers - so that's the only reason they're off of the car.







Heath

911/Q45 wrote:I did my guides without removing the radiator, but agree with Daedalus that removal is better.

I followed DAEDALUS' advice & removed the radiator today.I made a bunch of dumb mistakes, realizing them too late.

And, I was surprised to see there are two radiators.Actually, there seemed to be three coolers (two in one) because a red fluid, much to my initial surprise, dripped from the first radiator when, after struggling unsuccessfully with the brass connectors, I removed two of the quarter-inch hoses on the driver side. I had never thought about it before but that was probably the transmission fluid cooler.

I had a devil of a time getting most of the radiator hoses off without cutting them. I found myself moving farther & farther away from the radiator to get anything off (see photo).

Since the details would be, essentially, off topic, I'll post them separately.(That way, the next person removing a radiator still benefits.)

In addition, I definately need to bone up on adding an auxilliary transmission cooler. Also, while I've removed stuff, I guess I should research the possibility of replacing the hoses under the plenum (where I saw to my dismay pooled green coolant before I started the radiator removal process).

Wait a minute! What am I thinking? I should be finishing one job before starting another. Slap. Slap. Check my temperature.I'd better be more careful ... This take-apart fever is mighty contagious.

Q451990 wrote:Here are a few more pics from the guide replacement at T3.

Wow. How come your Q is so clean. I'm embarrassed to show pics of mine. Really. How do you keep your Q so clean?

I notice in almost all the photos so far, that the two "upper timing covers" are generally off the car (except in one of your photos above). I'm hoping to leave those upper timing covers alone.

Also, I just noticed T3 appears to have left undisturbed both the thermostat cover & the upper metal coolant hose. I already removed both thinking they would get inthe way. Darn. I think I'm coming down with a confirmed case of remove-it fever.

911/Q45 wrote:I'll bet the original water pump RTV was blue, but none of us have ever seen an original one.

Interestingly, the thermostat housing just above the water pump had blue RTV (just like the lower timing chain cover to the left & right of the water pump).