Timing Chain

[Dave]

Anyone here bother to change the timing chain when doing the timing belt? is it worth it to take care of voth at the same time?

--Dave

[Lyle's GTP]

I think when the dealers do the belt they do the chain too. However the chain will out last the belt by 2-3 times, but it will stretch some and throw out the timing a little. But that is easy to correct anyway. I wouldn't bother with the chain if it's the first belt change, do it for sure on the second change though. By the time that comes around you'll probably looking for a major engine overhaul anyway. If you are concerned with the chain stretch, just find TDC manualy don't use the harmonic balancer. I did this by putting a 10" steel rod down the #1 spark plug hole. Then I set up a dial micrometer to measure exactly where TDC was.

Lyle

[jmgtp]

I think when the dealers do the belt they do the chain too. However the chain will out last the belt by 2-3 times, but it will stretch some and throw out the timing a little. But that is easy to correct anyway. I wouldn't bother with the chain if it's the first belt change, do it for sure on the second change though. By the time that comes around you'll probably looking for a major engine overhaul anyway. If you are concerned with the chain stretch, just find TDC manualy don't use the harmonic balancer. I did this by putting a 10" steel rod down the #1 spark plug hole. Then I set up a dial micrometer to measure exactly where TDC was.

Lyle

are you kidding?! I really hope so. Changing the timing chain every 2nd belt change is just ridiculous. The chains generally last longer than the engine.

Reasons to replace the chain:
1.) you are rebuilding the engine
2.) chain went to hell
3.) your an idiot and you do it every 2nd belt change

and no, dealers do not do it when they change the timing belt. The chain is NOT regular maintenance. I don't know about everyone else, but I'm on my 2nd belt (over 100k miles on the engine) and its no where near close to requiring a rebuild.

[Dave]

.. I was just asking since I was gonna have the front of the motor a little more open...

--Dave.

[jmgtp]

.. I was just asking since I was gonna have the front of the motor a little more open...

--Dave.

I didnt mean to sound harsh, at least not towards you. It was a perfectly legit question. But, the response you got just seemed way off base to me. The easiest way to answer is, if it ain't broke don't fix it - that is unless you have the engine apart for a total rebuild.

[Dave]

the rebuild is comming this winter anyhow, this T-belt as ~40k on it from what I was told and I want to drive the car to Indiana so I figured I'd replace the belt before I went - I didn't mean to sound like I was offended by your response, I was tryin' to simply state that I was just curious -

I like these boards so much because you get good responses - fairly quickly too.

--Dave.

[Lyle's GTP]

Hey that's great that your car is that relible. I'm just going off what some mechanics have told me about the chain. But at 100000 miles and 2 belts, you've changed them early haven't you. Anyway I said that based on approximatily 200000Kms is probably a good time to do the chain too. I don't think I'm an idiot, but it is only a chain it may break. Or in our case where it has a plastic tensioner the tensioner may break, I don't know. You could call it "extreme preventative maintenance".

Lyle

[jmgtp]

Actually, 100k miles and 2 belts is right on schedule.

Belt 1: 0-60k and Belt 2: 60k-120k.

My car happens to be on its 3rd though. When I changed my cam timing I replaced the belt and all related components subject to wear. I think you need a new mechanic if hes telling you timing chains go after 120k miles. I'd bet that less than 1 out of 20 people on this board have required a timing chain replacement on a 120k mile engine.

[Lyle's GTP]

I personaly am my own mechanic, but I did work with alot of them when I was building engines for Optimax. That seemed to be the over-all consesus on the issue. I know that 99% of chains last as long as the engine, but like I said, "extreme preventative maintenance". Plus our chain works harder than any other motor, doesn't it.

Lyle

[brian89gp]

Normally on pushrod motors, 200k and the chain has stretched a little. I havn't heard of them breaking.

To get to the chain you have to take off the timing chain cover. That means you have to take off everything: alternator, power steering pump, crank pulley and damper, a/c compressor. After all that I'm not even sure if there is enough clearance to pull the thing off while in the car.

[Dave]

welp, then I guess I get to keep my chain and go for the belt only, and other suggested parts to change while I'm in there? (tensioners, ideler pully's or things of that nature?)

--Dave

[Lyle's GTP]

Tensioner and idler's would be a sound investment too.

Lyle

[grandprixgtp_91]

my chain tensioner broke on me but it was because i broke my belt at 7000 rpm and it broke the chain tensioner at the same time. the car had 260k km's on it and the chain was still good but i replaced it anyways and the tensioner exploded because its half plastic. but no my other engine has 220k km's on it and its still fine . but it is a big pain in the ass to change the chain. its very time consuming and you just barely have enough room to take out the parts. also its a bitch to take off the crank gear to drive the chain. just leave it if its fine.

Jake

[BlownL67]

...

Pullies and tensioner are always a MUST when doing a timing belt. Also you may wanna look into replacing the tensioner actuator and the actuator plate bolt too. If you are going to be in that deep, its a "might as well" thing to do. There is absolutely no need for timing chain replacement in these engines, unless that it the direct cause of a problem. From my years of ownership and being around 3.4's I have heard of maybe a handful of cases which the timing chain had been a problem. So unless you got the time, facilities, expertise and money, dont even waste your time with the chain. Just get the parts that were listed and you will be golden. Trust me - Mark

[Dave]

Sweet, I'm going shopping tomorrow

Thanks everyone!

--Dave.