Chain guide replacement - Possible jumped timing chain

[trw2k]

I am in the middle of changing the chain guides on a 90 Q45. I had cinched up the chains with ties close to the crankshaft but when I was removing the drivers side upper guide it seemed like I sensed the chain get a lot looser by the lower side guide. The lower guide had been worn completely away. The chain never came off but I am now not certain the cams didn't rotate and is now out of time. I don't want to get this back together only to discover it did. Is it possible for the chain to remain in place and the cams rotate and when I put the upper guide back on the cams will be pulled back to their position? How can I check and confirm the cams on the drivers side are still in there correct position?Everything was going so well up to this point thanks to this forum and now it keeps nagging at me.Thanks,Tim

[Raxephon]

Is it possible for the chain to remain in place and the cams rotate and when I put the upper guide back on the cams will be pulled back to their position?

No.

How can I check and confirm the cams on the drivers side are still in there correct position?

Remove the valvecover.

Its better than completely replacing the motor.

Good luck & Welcome to NICO

[trw2k]

Thanks anlasak, I was thinking of doing that to check for broken chain guide parts. This forum is fantastic!

[maxnix]

Thanks anlasak, I was thinking of doing that to check for broken chain guide parts.

They are probably in the oil sump. Must retrieve them all for your efforts not to be for naught.

[trw2k]

Yeah, the entire drivers side lower guide was almost completely gone...I hope it traveled no further than the sump pump. It actually looks like it was burned into a black pulp (i.e. picture)

One question: Can I determine the correct camshaft position by taking the other two guide covers off and with the crankshaft at TDC looking to see if the camshaft alignment marks line up with their appropriate alignment marks (yellow/gold link)?

[trw2k]

I am not sure if this is the old guide or carbon. It was all on the side of the missing guide.

[gniknave]

I just spent the whole past week doing this job... for the second time. I'm praying for you! This job is bringing back nightmares.

[trw2k]

ThanksWhat did you do wrong the first time?

I have been slowly proceeding and actually have been enjoying the process until I began to have the feeling the one belt seemed so slack on the one side and I started to wonder if maybe it had skipped a tooth or something. Now my pleasure has turned to dread I will get it back together and it won't run..so the job is turning into a bit more work then expected. I don't need the car right away so I am lucky in that respect. I am getting to know this car a little more than I intended.

[Raxephon]

Yeah, the entire drivers side lower guide was almost completely gone...I hope it traveled no further than the sump pump. It actually looks like it was burned into a black pulp (i.e. picture)

One question: Can I determine the correct camshaft position by taking the other two guide covers off and with the crankshaft at TDC looking to see if the camshaft alignment marks line up with their appropriate alignment marks (yellow/gold link)?

These should help you out a little.

zerothread?id=25201 zerothread?id=96820 http://q45.org/guidereplacement.html zerothread?id=92729 http://q45.org/chainguidehowto.html zerothread?id=140310

It sounds as if you don't have an FSM, so here's one for a '94 G50. http://phatg20.net/modules.php...d=203

I am not sure if this is the old guide or carbon. It was all on the side of the missing guide.

Odds are thats melted plastic from the guide itself The rest of it is probably in the oil pan/pick-up tube

This link will now be your new friend zerothread?id=77266

[trw2k]

Thanks again anlasak!! You rock

[Raxephon]

Where is this pic from?

Edit: Sorry, image tags weren't working for me for some reason.

[trw2k]

The timing chain pic? from a screen shot of the chain guide zip I think I downloaded here somewhere

[Raxephon]

Its just a little odd.

The timing chain should be 2 silver links, (camshafts), at the top and a single gold link, (crankshaft), at the bottom.

That diagram says the top links are gold & no bottom link. wtf?

[trw2k]

The other folder that came out of the zip was a 2003 Q45 manual. COuld this be the diagram for a 2003? I don't know....

[gniknave]

That is a diagram for the 2003. Notice the passenger side hydraulic tensioners location. Interesting to see this however!

trw2k, I first did the guide job on my own Q last year. Then on a fellow Nico member's Q. Just finished it Sunday actually. Take your time, and stay positive.

When I first did this job, the first thing I questioned was the slack on the timing chains. Didn't turn out to matter however. If you hand turn the crank (which you should do anyway before putting the timing cover back on) you'll see that everything will tighten up. Just make sure to torque the Crank bolt 270ft lbs so the oil pump chain doesn't slip and cause oil starvation. I found this part is much easier to get right with air tools...

As long as you zip tied the chains and they didn't move themselves, then you don't have to worry. When you remove the tensioners there will be some slack...

[trw2k]

I must have the entire manual for the 2003 than. I am glad I found that out! The lower part of the chain seems so much looser than the top. It seems like the top part should be loose and the bottom side should be tight...I guess I will see soon. I am curious to see how much it tightens up. Do these chains ever get too loose? How would I know it is too loose? I need to order the replacement parts however first.

I have the same 90 Q45 as you have gniknave (minus the mods and improvements). Nice car!

Thanks for reminding me about tightening. It just dawned on me that being keyless it will depend entirely on tightening to 270ft lbs.

[Raxephon]

Do these chains ever get too loose?

Only if the tensioners/guides allow it or the chain is damaged

How would I know it is too loose? I need to order the replacement parts however first.

It will skip teeth at the cams or the crank.

[gniknave]

The lower part of the chain seems so much looser than the top.

Do you have the tensioners (aka slack guides) off? The tensioners are the long parts with one bolt going into each one, with a hydraulic tensioner pushing up against them. If you have the tensioners off then that would be why the chain seems loose.

Have you tried and turning the crankshaft (put the crank pullen on and turn it a bit) to see if the chains tighten up? You can do this with the front cover off. Just make sure the zip ties are removed...

How many miles are on your Q? If it's well over 200k, maybe the chain is stretched. However that doesn't seem like your issue.

Here's how my passenger side chain looked right after I took off the front cover (before doing anything else):



I honestly don't think you have to be worried about the slack. Just make sure you turn the crank a few times before closing the cover to make sure everything looks smooth. If it's still slacky after turning it, then I'd worried. Where are you at with the job right now? Be sure to get the guide bolts in straight and don't overtighten them. If you do, you could snap the bolt. this happened to me the first time I did the job and I ended up using JB Weld to get the two halves together (bad practice). The owner of my former Q that I did that to said he's had no problems whatsoever even with that JB Weld situation, but please avoid that!

I have the same 90 Q45 as you have gniknave (minus the mods and improvements). Nice car!

Thanks!

[trw2k]

Could it skip teeth while the engine was running by chance and also skip back? This car was acting so wierd before I decided to fix it. It would run really rough and the next day run absolutely perfect. Then it would run rough and smoke and then be fine. It seemed like occasionally I was burning up a piece of the guide..smoke would be coming out the back and then stop. Strange stuff. Here are some pics of the wear on the surrounding parts and the slackness of the chain.

[trw2k]

I posted my post before I saw yours gniknave.Thanks for the pics.I took all the guides off so it sounds like it should look pretty slack. Maybe I shouldn't have done that.It has about 175,000 miles on it.I guess I will have to wait and see how much slack is left after I put the new guides in. I have just removed them and have to buy the replacements at this point.

[gniknave]

What color was the smoke you were seeing?

That slack does indeed look a little weird. I wonder if the chain did actually skip teeth. I'd still put the new guides in and then try to turn the crank to see if everything tightens up. The only way you're going to find out if there's a problem at this point is to finish the job.

[gniknave]

I posted my post before I saw yours gniknave.Thanks for the pics.I took all the guides off so it sounds like it should look pretty slack. Maybe I shouldn't have done that.

Ok, so I take it it wasn't that slack before you removed all the guides? If it wasn't, then I wouldn't be the least bit worried.

[trw2k]

Yes these pics were taken after the guides were off. Thanks for the encouragement!! The smoke was white but it smelled different than a blown head gasket kind of smoke. After seeing that black pulp I am thinking maybe that was what it was...Thanks for all the help!

[gniknave]

White smoke and a rough idle without a coolant like smell sort of sounds like an injector issue. That wouldn't be uncommon. http://www.q45.org/roughidle.html

[trw2k]

Thanks for the link. I have smelled fuel occasionally from around the injector area. Strong enough that I smell it without lifting the hood. WHen I look for the source I can't seem to find it. It did have one injector replaced but it also seems like the gas around the Seattle area can very in its quality. The last time It smoked I ran it a high idle for around 10 minutes and it cleared up. I don't want to get off the main thread subject here though. I need to get these parts ordered today. It sounds like the cheapest place to buy the replacement parts is from Joe at everythingnissan.com

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

[Q451990]

trw2k... if you haven't gotten ahold of a 90-96FSM, I would highly recommend it. Then go through the process of re-timing as outlined in the manual. I think it would definately be worth pulling the oil pan and removing the other guide peices and seeing what's in the pick-up. I know it's a lot of extra work, but it's the only way to go after coming this far.

Also, for anyone reading this post later - when I was watching my guide job, the tech. used the bolt holes through the upper t/c covers as a cable tie point (see red line in picture below). From what I understand T3 (with an experienced tech. that does dozens of these per year) expects a 10% rate of slipping - so it's not uncommon.

Good luck!

Heath

[Raxephon]

It should not slip at all if you :

1. Set at TDC2. R&R Passenger-side guides only3. Rotate crankshaft 120 DEG.4. R&R Driverside guides.

The "slipping" is from the tension the valve springs put on the cam lobes causing the camshaft to spin when the chain has enough slack to allow it.

[texasoil]

Regarding the smoky operation intermittently B4 timing chain--most likely its a flaky connection at the MAF (mass flow air sensor) wiggle it. Better yet, take it off, clean it carefully, apply a little Stabilant-22 to the contact and reassemble.

[trw2k]

Interesting..thanks. I have searched a little but I am not sure where I would get a manual. I called the dealer to price parts and they are literally twice as expensive as the prices quoted above. I didn't ask about a manual though.

[Raxephon]

Interesting..thanks. I have searched a little but I am not sure where I would get a manual. I called the dealer to price parts and they are literally twice as expensive as the prices quoted above. I didn't ask about a manual though.

I already posted a link to a Factory Service ManualG50 = Early Q45

These should help you out a little.

It sounds as if you don't have an FSM, so here's one for a '94 G50. http://phatg20.net/modules.php...d=203