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timing chain

djames6

New Member
Joined
Jul 26, 2008
Messages
2
Hi I have a 2002 Avalanche with a little over 101,000 miles. At what mileage should the timing chain be changed?
Thanks
Dave
 
Timing chains are not like they used to be back in the day. Timing chains these days are designed to last a long, long time. I have not heard of a timing chain breaking/slipping on a GM engine in a long time. I have certainly never read about anyone having problems with their timing chains on this site. There are many members here that have close to 200k miles on the original engines.
 
02 Z71 said:
Timing chains are not like they used to be back in the day. Timing chains these days are designed to last a long, long time. I have not heard of a timing chain breaking/slipping on a GM engine in a long time. I have certainly never read about anyone having problems with their timing chains on this site. There are many members here that have close to 200k miles on the original engines.

What he said.

I didn't even change mine whn I changed the cam.  There are aftermarket that are stronger but why?  I regularly spin mine to over 6000 rpm and the timing chain is the least of my worries.

 
Thanks for the info. If that's the case, then I guess I will not go to the expense of replacing mine.
Thanks
Dave
 
Good to know.  I was driving down the road yesterday, and with about 120k miles, it occured to me to look into this.

I do think a fuel pump may be in my near future though.
 
ggates said:
Good to know.  I was driving down the road yesterday, and with about 120k miles, it occured to me to look into this.

I do think a fuel pump may be in my near future though.

That is always a possibility.  From what I have read, the best way to ensure long fuel pump life it to make sure that you don't regularly run the tank down below 1/4 tank since the fuel pump is cooled by the fuel in the tank. Many member here also have close to 200k miles on there trucks with the original fuel pump, but then again a few members have replaced there quite a few times.
 
ggates said:
Good to know.  I was driving down the road yesterday, and with about 120k miles, it occured to me to look into this.

I do think a fuel pump may be in my near future though.

Mine fuel pump just dropped dead,at 118000km(90000m?)
 
Why would you not suspect that it was an interference motor?  I can't imagine there being anything but interference motors being sold these days by the major auto makers.  The GM dealer is "smart enough" to know when they see what you saw it's cheaper to replace the motor than to start throwing parts at it.
 
:welcome: to the club Crznit


All I can say is WOW. I would have just got a rebuilt long block.
 
Nobody was trying to attack you and nobody was trying to say you had to put a new motor in they were telling you what they would do in that situation you did not tell anyone this was a low budget project.... i know when i see a nbs avy i generally think that person has some money.... we are here to help people out and enjoy the truck that is the avalanche they stated that that is what they would do ... if thats the attitude that you are going to convey though when they give their .02 or anyone else then i would have to say on my behalf its a welcomed goodbye  :wave:
 
I'm guessing he has no idea what a long block is.

Good luck with your project. :wave:
 
MS03 2500 said:
I'm guessing he has no idea what a long block is.

I think you're right.

If you are still lurking Mr. Crznit, I had a lifter go out in my truck back in February, and took the cam and oil pump with it.  I thought about replacing the motor, but at no point looked at buying a new one - never even priced one.  (This truck and motor had over 260K miles on it at the time.)  Frankly I'd be surprised that a new motor would be $6K - I bought a new 350 for a '99 suburban 5 years or so from GM for less than half of that.  What I did price though, and thought seriously of doing was buying a used motor with under 100k miles for under $600.  Maybe that's in your customer's budget.
 
djames6 said:
Hi I have a 2002 Avalanche with a little over 101,000 miles. At what mileage should the timing chain be changed?
Thanks
Dave

I have a 07 LT and my check engine light came on. Took it to percision auto and they said both my timing sets need to be changed. From what im reading here I don't know if that true of if they are just trying to squeeze $2k out of my pockets. Right now im in a rental because they said if i drive my truck i could blow the engine.  ???
 
07TriniAvalanche said:
I have a 07 LT and my check engine light came on. Took it to percision auto and they said both my timing sets need to be changed. From what im reading here I don't know if that true of if they are just trying to squeeze $2k out of my pockets. Right now im in a rental because they said if i drive my truck i could blow the engine.  ???

What were the OBDII Codes that P-Tune pulled?
 
Get a second opinion.
 
07TriniAvalanche said:
I have a 07 LT and my check engine light came on. Took it to percision auto and they said both my timing sets need to be changed. From what im reading here I don't know if that true of if they are just trying to squeeze $2k out of my pockets. Right now im in a rental because they said if i drive my truck i could blow the engine.  ???



"Timing chains" on LS engines or any previous small/big block Chevrolet motors do not need to be changed out as part of schedule maintenance. They will typically last the life of the motor and rarely fail.

I could be wrong but as far as I know there are no OBDII codes that tell you there a problem with your timing gears or chain. There's a camshaft position sensor that can go bad, but that doesn't mean your gear set needs to replaced.

If you own or owned a vehicle with a timing belt, they are the ones that usually need to be changed as part of scheduled maintenance.
 
While it is not an Avalanche or even a V-8 engine for that matter, we experienced a timing chain and/or tensioner failure on my wife's 2006 V-6 Cadillac CTS a couple of years ago.

The failure began slowly and progressed over time.

The first notice of the problem was a rougher than normal idle that my mechanic made me aware of while I had the car in for an oil change and lube.

I very seldom drive the car and it always seemed fine to me.

Some time later, we got a CEL and the code indicated some kind of timing error, but did not reference the timing chain specifically.

At first, a little research pointed toward a possible camshaft position sensor failure.

The camshaft sensors were very hard to come by for that engine, but I located one and prepared to have it installed.

Once I got the car into the shop, it was discovered that the actual problem was a fairly common one with those engines in that the very complex set of timing chains and tensioners for the variable cam timing system were worn out with only 80K miles on the engine.

My mechanic had to purchase a special tool to hold all of the various gears and whatnot in place and it took several days to complete the repair, where they are usually much quicker that that.

But the new chains and other stuff solved that problem and the car has been smooth as butter ever since.

As far as I'm concerned, these new tech engines are just too durn complicated for their own good sometimes.

:E:
 
I agree, the more complicated, the more to go wrong... GM was using a nylon cam gear for awhile and I was supprised how well it held up, but I have seen them crumble.. Very bad for the rotating parts since they are all interference motors...

I always change them (or at least the chain) if I open up or rebuild a motor no mater how many miles it has on it.
 
Especially with a double overhead camshaft V6 engine.
 
They had problems with the early 3.6L V6's. It appears part of the issue was going to longer oil change intervals, at least on the Enclaves. We could have gone 10K miles between changes if we had waited on the "change engine oil" message. GM "recalibrated" the oil change interval down to 6000-6500 miles in 2009 and the majority of the stretched timing chain issues appear to have gone away. I used nothing but full synthetic on a max of a 6k mile change interval, mainly Pennzoil Platinum, on the 3.6 since it's been shown through UOA to shear the oil pretty badly. Pennzoil Platinum and Ultra were particularly good about holding up against that shearing in the 3.6.
 
MyBigToy said:
They had problems with the early 3.6L V6's. It appears part of the issue was going to longer oil change intervals, at least on the Enclaves. We could have gone 10K miles between changes if we had waited on the "change engine oil" message. GM "recalibrated" the oil change interval down to 6000-6500 miles in 2009 and the majority of the stretched timing chain issues appear to have gone away. I used nothing but full synthetic on a max of a 6k mile change interval, mainly Pennzoil Platinum, on the 3.6 since it's been shown through UOA to shear the oil pretty badly. Pennzoil Platinum and Ultra were particularly good about holding up against that shearing in the 3.6.

This is part of my understanding, as well.

The engine in our CTS is also victim of a common oil consumption issue where I have to add a quart every two weeks or so.

This appears to be from another poorly designed PCV system from GM.

We found that some of the oil that was missing from the crankcase got deposited in the plastic air intake tubing AHEAD of the throttle body.

Imagine my surprise when I took that tubing off to clean the throttle body and dumped a good portion of oil onto the ground from a device I expected to be oil free.

Now I check the tube at regular intervals and clean as needed.

Some people on the Internet have resorted to adding an oil catch can in line with the PCV hoses to deal with this issue.

Anyway, by adding a quart of fresh oil every couple of weeks to keep the six quart crankcase full helps to keep fairly fresh lube in our engine.

Or so I keep telling myself.

In addition, ever since the timing chain repair, I now change the oil at 50% on the oil monitor instead of trying to stretch it out longer toward 0%.

With the crappy PVC system, the oil tends to get much darker, much sooner than the oil in my EXT anyway.

I would think that if someone wasn't paying very close attention, they could trash one of those engines in no time.

The car runs and handles too good to get rid of, but it does take a little more attention than I would like.
 
My 2005 CTS had the same issue with oil and the PCV system..

:jacked:

But we are getting way off the original topic of a timing chain on a 2002 AV..
 
Randy said:
My 2005 CTS had the same issue with oil and the PCV system..

:jacked:

But we are getting way off the original topic of a timing chain on a 2002 AV..

Yeah, but it was fun while it lasted.

:laugh:
 
So I know it's been a while with this topic but I have a 2002 and I get all the symptoms of timing chain issue Power loss, back fire in engine Truck has 353K mile without any major engine work and I'd hate to throw another motor in it if it's the timing chain. Any one replace on an 02 timing chain?
 
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