same old chain guide issue... do it myself?

[ScottJackson]

I'm sure everyone's tired of people asking about chain guides with the early Q45. I have a 92 Q45a that I'm wanting to put under the wrench for some fresh guides. I called the dealer in Des Moines and they said it would be $2100 in labor alone. They also said that it's basically the same as replacing the chains too. I says "BS" and that was the end of the conversation. Kansas City dealer quoted $2500 or so. I live in southern Iowa and don't think there's much option but to try it myself. I'm rather good with mechanic stuff and have built some domestic V8s and done the spark plugs on the Q. The plugs weren't too bad and just took a little patience. From what I understand, the critical moment in the chain guide replacement is when the motor is first started and there isn't oil pressure to the tensioners to keep the slack out of the chains. Is there an easy way to pressurize the oiling system before starting the car up when the new guides are installed? I was thinking maybe a tapped and plugged passage to an oil galley that I could put a fitting into with a hose connected to my old crown vic which I could start up and push its oil into my Q motor. What parts do I need? Do I need new hydraulic tensioners or can I use the originals? If so, I would just need the guides, longer bolts, front cover crankshaft seal, oil pump guides, and oil pump chain, correct? What's the best way to keep the chains from jumping the sprockets during the guide replacement? How about using a thin wire and wire the chain together under the cams to keep them from going too slack in the midst of the deal? Guys that have done this, does this sound like disaster waiting to happen or a reasonable plan? If there is no oil passage to connect with a hose fitting, could a oil filter be tapped and thread a fitting into it and pump oil into that? As for the front cover, all that needs removed is the lower one piece cover itself right? Does the alternator, power steering pump, A/C compressor, water pump need to be removed? I can see that the idler tension pulleys will need removed, but that's no big deal. As for changing the oil filter, I've just been taking the 4 10mm nuts off the fan and removing the fan to get to the filter, is this the regular way of doing it? Where's the best place for me to get just the needed parts for this job? If it's not something I should try, is there any good places between Kansas City and Des Moines/Ames that will do it for less than $2000? I kinda wouldn't want to take it to Des Moines even if I had $2500 because the "most experienced tech" obviously doesn't know what he's talking about, much less doing with this chain guide issue. Oh yeah, I'm new here but have been reading on and off here for the last several months, great site. ThanksScott J.

[DAEDALUS]

Welcome Scott. How many miles on the car? The job is more difficult with the Active I think, but not sure by how much. I don't think you have to worry that much about the oil pressure. Most people just unplug the pump/injectors and crank the car several times before firing her up. You can rotate the oil pump before installing the front cover...it might not help, but it couldn't hurt. You should replace the tensioners while you're in there...depends on how long you want to keep the car. They don't cost that much in the grand scheme of things. All aux components stay in place, but removing the water pump will give more access. Not a bad time to replace the pump too for around $80, and the thermostat as well for maybe $10 more. One of the PS brackets has to be removed.Using wire on the chains should be OK if you take out enough slack. The tricky part is that the cams tend to jump all of a sudden. There might be no force on the chain at all, then *CLACK" the cam snaps. Use patience. You need to keep the chain from jumping while still allowing enough slack to work the new guides in place.The correct way to change the oil is from below, but at least it sounds like you're avoiding the delicate MAF.

Good luck!

[Q45tech]

T3 Atlanta still has the $1,000 special [without the oil pan drop] for guides and oil pump chain replacement.

Been a while since anyone drove in from IOWA.

If you DIY, be sure you follow instructions to the letter, you must have a lift............and plenty of strong black tieraps.

A first timer has a 9 out of 10 chance of doing it wrong, it gets better after you have done 10 and by 100 it is the converse.9 out of 10 times you get it right the first time.

With the full blown valve cover removal and the total chain replacement the odds are much much higher that it gets done right the first time............why you pay a dealer $2500.

[Qdog]

I see you have another Q, is that one next for chain guides ? In August 2000, I had the full job done at Mark Bass Nissan in Joliet, Il, by their Nissan master tech. This was his second Q, but third chain guide job he had done. Earlier that summer he had to redo the first job, after putting in the wrong bolts on the tensioners. No mistakes on my job that I know of. They replaced 3 chains, tensioners, guides, resealed the valve covers (they needed it anyway), new front crank seal, a sprocket, 3 belts & 3 hoses, 8 new sparkplugs, all for about $2250. Almost 60k miles later, no problems. They gave a Nissan 12month 12K mi. warranty. The guides were all intact at 111K on the motor. Is the timing chain setup on the VH45 similar to the Nissan 24v V6 ? If so then any (good) Nissan tech should be prepared for the job.

[ScottJackson]

so instead of wire folks use black zip ties? Where do I get the complete instructions to follow to the letter? As far as the cams snapping all of a sudden, I know how that goes. I did the timing belt on my sister's 90 Toyota V6 4runner. On that it was simple though, just mark the cam sprockets with paint marker along with the crankshaft sprocket before taking it apart. Would that not work in this case? Are the cam sprockets not visible? I don't have a lift but it really looks like there's a lot more room to work from top. I do have a couple floor jacks and good stands. My car has 138K miles. I got it off ebay last year and only drove it until my first car wash when I found out the silicone on the timing cover was blue. I asked the seller that question specifically and he said it appears dark grey or black. Well, that was just the oil grime covering the silicone. Under the oil fill cap it's perfectly clean. It doesn't smoke on startup and runs great. When I got it, it would cut out at anything over 1/3 throttle. After a little digging I decided to take out the fuel pump. It had been installed with a LOT of orange silicone as a seal instead of the rubber O ring and of course the gas made the silicone jelly and it clogged the pick up strainer. That's a good deal, in Georgia. How about around here? Maybe St. Louis? The car drives great and i'd bet there aren't any chunks in the oil pan. The only problem I would see with using the black zip ties for holding chain tension is that they can't be gradually loosened like a piece of wire.

[90Q45blue]

Jesda is in St. Louis. E-mail him about shops to use there, though he hasn't done his guides yet. :rolleyes (Just giving you a hard time Jesda)

Nick

[maxnix]

You can probably get it to T-3 on a trailer for less than a dealer in St. Louis. Anyway, congratulations for having enough sense to realize the importance of hte chain guide update. If you read enough here, you will see 3 1992 Q45s which have failed catastrophically in the last few months with no warning.

Look for posts by Daedalus, forecast, and Q45tech. Read them all, and get a FSM.

[Q45tech]

Understand T3 just changes the guides and oil chain.........less time consumming but much much more prone to a mistake [and then T3 having to eat the cost of pulling the valve covers and retiming [T3 risks losing $700] to get the price that low.

Most people won't spring for $2000-$2500, so to keep the Q on the road [available for future repairs and income--maybe] we do the quick and dirty and risk the extra work from a slip.

If the guides are broken, the owner agrees in advance to pay another $500 for an oil pan drop and clean.........that way we all share some risk, yet the prices remain affordable to most. Instead of forcing everyone to pay $2,000 or more.

Socialism in action. Plus a good part of T3's income depends on Q45..........if they are dead in the junkyard they don't do much good for anyone........except parts.

The job on a Q is much harder than any other Nissan or MB or BMW or Jag V12.

The tensioners have internal springs to help before the pump up.

[ScottJackson]

you must be referring to the inline 6 cylinder motors. the DOHC V8 in my 540i looks much like the Q motor, but with an LS1 style intake. I do have the service manual, and upon closer inspection, AHAA- I do see that the cam sprockets won't be seen unless the valve covers and such are off. I'll have to look for a boroscope... So, could a person take a piece of plastic wrap (kitchen stuff) and put it over the cam gears and then put some JB weld putty between the gears and let it harden? this would keep the cams from moving assuming there was enough mass of putty on both sides off of center to prevent them from turning. To remove it, you'd just need to use a flat blade screwdriver and pop the plugs out when you're done. I don't think I'll follow the service manual's proceedures... Step 1. Remove engine and transmission.

[911/Q45]

No JB Weld please! Just tie strap the chains tightly, once they are ready to be released it won't need to be gradual. Be sure you get all the little bolts off the front cover before you pry it loose. There are a couple that are buried pretty deep behind the power steering pump. Also use the little hook to hold the passenger side tensioner while you change the guides and remember to unhook it before you close things up.

[Q45tech]

I love to hear owner success stories, but for everyone there are usually 4-5 horrors. We learn by mistakes including certified techs..........we ask how many mistakes they made if they say none they are not suitable employees.

[ScottJackson]

well, I'll need parts at least. It's all becoming very clear with the radiator out and many of the bolts removed. There is obviously no feasible way to hold the cams still other than to use the existing chain and tie it to keep them there. The silicone on the tensioner cover (passenger side) is obviously factory original. I don't forsee the active susp. causing an issue except one of the lines for it made it tight getting the radiator out. Right now it's time to take some digital pics before I go any further. The crankshaft hub is quite close to the cover, havta see about getting a gear puller that will fit in there. Also obviously need to find a thick washer to put on the crank snout so I don't damage the threads for the bolt. I used the starter to pop the big bolt free, what's the best way to tighten it? Just lock tite and tighten it as much as possible? I'm gonna spin the crap outta the oil pump once it's all back together, probably with an electric drill and a socket to go over the nut, then hook up the chain for it and reassemble. I will also disconnect the fuel pump and turn it over before starting. So who has the best deal on the parts I need, knows just which ones I will need, and can get them to me relatively soon? my 91 Q I'm pretty sure has had the guides done, the silicone is orange and relatively fresh. It was hit by hail last year so if the guides go out on that 206,000 mile motor, no biggie.

[Rex]

Call Joe at Scottsdale Infiniti (Everything Infiniti banner, I think) tell him you're from NICO and you'll be getting a deal.

[dsmtuner]

how could you tell if the chain guide hasnt been changed yet?

[ScottJackson]

there is no sure way of telling if it's been done. The factory used blue silicone on the tensioner cover plate on the passenger side. This is a small plate with 3 10mm bolts. If it's blue, get the chain guides done. If it's orange, black, grey... and you aren't too thrilled about spending the cash to have it checked then they probably have been done. Some have suggested that one could use a boroscope and look thru the opening of the passenger side tensioner cover to see inside and determine if it has been done.

[Q451990]

The RTV color on the inspection plate isn't really a good indication, since it typically doesn't get removed during the guide swap. The RTV around the front cover, is a much better indication.

One thing I remember from watching Byron (at T3) do the guide job, is that instead of removing the P/S pump, he just removed the pully from the front. A chain wrench wrapped around the harmonic balancer and braced against the crossmember that holds the tension rod - plus a 3-4 foot bar and socket on the harmonic balancer bolt should get it back in. 3 ft bar with 100+lb pressure should equal 300+ft/lb if I remember correctly. Getting enough torque there is critical, since the oil sprocket will slip if you don't.

It might also be worth your time to cut a peice of cardboard to put in front of your condensor coils to keep from banging them up... believe it or not my radiator stayed in during the guide job - but it's much easier on a lift. If your rocker covers are leaking at all, I'd go ahead and pull them so you can keep an eye on the chain positions on the cam sprockets. Nothing like getting everything re-sealed at the same time.

Please keep us posted!

Heath

[maxnix]

Boroscope is a non-conclusive intstrument, from what I recall. One cannot see enough of the chain path to tell if the guides are sufficiently intact or not.__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

[Q45tech]

I'm glad we don't get the same moaning and resistance about changing timing belts on 98 [first year of interfearence engine] and later LS400/430........its $1100 every 95-105,000 miles.

We recommend early because you should see the condition of many belts at 105k........think the new VVT places more stress on belt compared to 90-97 engines.

You need to find a dealer who will just do the guides for $1500 not the whole chain job.........they are around you just have to keep asking.

[ScottJackson]

I've got it all ready to pop open except for the crankshaft pulley/hub. Up to this point I don't see any easy spots to mess up the deal except that someone going into it completely blind could easily take out the driver side tensioner or loosen the two 10mm nuts holding it down before having the cover off and the chains zip tied. That is a good point about not trusting the silicone color on the inspection plate, the silicone is light blue all the way around. I'll be taking digital pics as I go, I'll try the job from the top. This is where I think the active susp makes it more work. The lines/hoses for the active are in the way from the bottom. I can look up from the bottom but won't be able to work from down there. I dread the active going out more than the current chain guide project, although both are pretty intense as for apprehension. How tough is it to replace the dust boots on the factory hydraulic shocks? The active works great now but I hate having the shiny shaft exposed like it is with the bad dust boots. I was wondering if it would be a good idea to make a hook with a piece of coat hanger wire and attach a spring to it that could be hooked to the crank timing chain sprocket or somewhere similar. The other end, the hook, would go up to between the cam gears on the chain and keep constant tension the the chains. This would be used in conjunction with the zip ties down lower. The beauty in the spring is that it would keep steady tension on the chain and still allow the chain to be moved while installing the new guides. I may try a spring across the chains too where the zip ties go and if I have to cut a too tight zip tie I could have the spring there to hold tension. With the new chain tensioners, is it beneficial to "pump" them in some oil to get them primed before installing?

[DAEDALUS]

Don't use a spring. How do you know how much tension you need on the spring to offset the valve spring compression? Tie them together, tight and *secure*. Zip ties and/or wire are fine.

[ScottJackson]

the idea behind using a spring loaded hook up between the cam gears was for tension but mainly to pull the slack of the chain down to cover more teeth for more grab. Of course it would need to be a strong spring. Ok then, I'll just skip that idea if I can slide in the new guides and such with the zip ties really tight. Guess I was under the impression that it was a fine line between too loose of zip ties and too tight preventing installation of the new guides. I'll probably get a second set of hands (my dad) to hold the chain also between the time I take the old guide out and insert new one and bolt it up along with tensioner. Is there any specific crankshaft position where the cams have the least amount of force from the springs to make them move in one direction or another? I was just planning on having it so #1 is about 15 degrees before top center so no pistons would be hit if a cam happens to snap. In hindsight, I shoulda done this when I did the spark plugs a month ago. Oh well...

[911/Q45]

You don't have to worry about valve/piston contact during the job. Not enough force is applied to cause damage. Cranking the starter with interference would be a different story! Stick with TDC in case you have to retime the cams due to a slip.

[ScottJackson]

Ok, I've got the front cover off and all looks good. None of the guides were broken and none appear cracked. I took out the slack side guide on the passenger side and it's dated 1991 so they haven't been changed. I zip tied the chain together at the crankshaft sprocket before removing the slack side guide. After removing the slack side guide I zip tied it in the middle to the chain on the tensioner guide. I need to get the driver side slack guide out now and it isn't coming easy. Do I need to take off the oil pump to remove it? I've got a zip tie on this chain also by the crank sprocket and it's hella-tight. I would think that the chain needs to stay tight mainly near the crankshaft sprocket. Also, my oil pump chain does have about 1/4" of slack in it but looks good otherwise. Should I order a chain to replace it? I've got the guides, tensioners, longer bolts, and crank seal coming tomorrow. I'm taking a few digital pics on the way and will see about putting them up on here soon. The hardest part up to now has been removing the damper, I had to modify a puller by welding on tabs and grind a rib on the timing cover to get behind it. What's the best way to put it on? Should I stick it in the oven to 275* like I have with other dampers to make it go on easier?

[Q451990]

I'd replace the oil chain too... they tend to have substantial stretch.

Heath

[DAEDALUS]

Getting the old guides out is easy. Cover up the oil pan and shatter them with a hammer/chisel. The damper came off easy with the Sears $30 puller. It's the only one reasonably priced I could find that is large enough. For getting the damper on, just tap it on as far as it will go with a rubber mallet and tighten the bolt to 270 ft-lbs. No need for an oven.

[ScottJackson]

does the oil pump need to be removed to get the driver side slack guide in? If so, I'll just take it out now to remove the original guide without busting it up. The only other way of getting the guide in/out in one piece is if the chain has quite a bit of slack, such as taking out the tension guide and then removing and installing the slack side guide. But this would cause a slack chain which is bad, right? I sure hope the new guides come in today....

[Q451990]

The pump doesn't need to come out. I'm not sure what advice I can give you, but they didn't break mine. I've never heard of having to break any guide to remove it - and even if you did, I'd think putting the new one in would be a problem as well. Maybe you need to relocate the cable ties. From what I remember they used ties at the top near the head cover plates above the front cover.

I'm sure they took the pump chain off... maybe a sprocket on the oil pump too?

Heath

[redmanfx]

I'd be real interested in seeing your pics and a anything else you want to add about this job. I have a 92 Q45a as well and it purrs like a kitten right now with 250k on it. I can't get over how quiet it is. Did you hear any racket that made you want to change the guides or did you just feel like it? Are you working this by yourself? I figured it would take me three days or so to do it by myself and two if I had help. Does that sound close?

I would have to do it myself because no dealer here will even touch it and the Infinity dealership 130 miles away said $2300 in labor alone. I think they also said $1500 in parts.

They are out of their mind!!

Thanks for tackling this first!!!redmanfx92 Q45a

[DAEDALUS]

I would bet dollars to donuts your driver's side guide is in your oil pan...here, here, here, here and over here.

[azskygod]

Hey guys, don't forget I just finished a complete chain guide replacement AND retime a couple of months ago on a '91 Q45A... Lot's of photos too!

AZSKYGOD