Timing Chains at 50k

[harleymonster1]

50k the odometer....check engine light comes on, press on- star.....they tell me the cams are out of timing have it serviced. Check engine light goes out, dealer explains several codes have come and gone but the final diagnostic was not a computer problem but streched timing chains.
This had been an ongoing problem for several months, the first time the light came on it was a gas cap. After several more check engine lights and many on- star chats..(.they all knew me by my first name), finally the dealer figures it out, timing chains have to be replaced.WTF.
Anyone with a similar issue??????

[Panzer Leader]

Not on mine. Most of my past cars were timing belts that were replaced around 100K miles. I have never had to replace a timing chain under these conditions. Never heard of a chain stretching but rather breaking. Another question would be, what happens if it does break. Is it a non interference design or will the valves and pistons be damaged? Normally, when a belt is replaced one would replace the water pump as well. (Since you are there anyway) Please keep us posted on developments.

[Bear]

That's a bummer ! With the modern technology available,engineering ,and testing methods used before the cars start production,it's just not acceptable for a modern car. Have you done any mods, cam,valve springs,etc? That might have contributed to your problem, more load on the valve train could equal more wear on the chain?

[dandragonrage]

Chains DO stretch but 50k seems like way too short a time for it to happen in. Maybe your chain was defective from the factory and thus prone to stretching sooner than it should.

The dealer could also be wrong...

[Sephiroth]

the LS2 Timing chain's service intervale is 150K miles, so no, it should not be common.

And your car does not have cam(s)

it has a single cam.


Maybe your chain was defective from the factory and thus prone to stretching sooner than it should.


This is my guess, or the tensioner was installed incorrectly, or damaged.. ect.

[TomPierce]

Stock timing chain tensioners are prone to failure - usually it does not damage anything in the motor - in fact, it may not even be apparent that the tensioner is broken unless you disassemble the motor for some reason. This could be part of your problem.

http://forum.grrrr8.net/showthread.php?t=21627

[Panzer Leader]

Is this the same setup on the 3.6L V6? This is a V6 engine he is talking about.

[Sephiroth]

Is this the same setup on the 3.6L V6? This is a V6 engine he is talking about.

The LY7 System is much more complicated. OP if you have a LY7, I would not hesitiate to take it into the dealer. Eye spy 7 tensioners and 3 chains in this picture.
http://i989.photobucket.com/albums/af16/puppabriggy/P7060030.jpg

you should know! D= you posted in this thread
http://www.g8board.com/forums/showthread.php?p=586251

[Bear]

WOW !!!!!!!! That's just sumthin looooking to come aaaaaparrrrt.

[Sephiroth]

WOW !!!!!!!! That's just sumthin looooking to come aaaaaparrrrt.

The only engine I've seen that's come close to the stupid complicated mess the LY7 represents is a DOHC 40v audi V8. All the chains and tensioners are on the back of the engine(requiring a power train separation) although I'm pretty sure it has only 1-2 chains and 3-5 tensioners/guides. The LY7 still takes the cake seeing as even the GM service manual is littered with inconsistencies in the chain service procedure.

[Panzer Leader]

Looks like the layout for a roller coaster at Coney Island. Thanks for posting the picture. Is the tensioner that device that is to the right and up from the center of the front of the engine? The device with the "X" marked on it.

[harleymonster1]

Thanks to you all and i will be asking more indepth questions when returning to the dealer to have it serviced. The wacky thing is as of right now the check engine light is off and no issues have arised, according to my dealer as well as the folks at on-star the engine will operate at 100% with the system resetting itself and the cams are in sync. Listen, i am no machanic but i am not an idiot either i have to believe that once an issue comes to the fore-front that issue continues until rectified, yes or no. I change the oil every 3-5k depending on my travels, i am an aggressive drive but not a stunt driver and i service the vehicle according to dealer specs. The car is an 08, and the design of the chains ( all three of them running the double cams ) have been around for a couple years but new to the G8 in this model year. There have been a couple of similar posts on other sights but i will keep you LY7 guys up-dated........Have a great Holiday and b safe.

[-Ray-]

I would insist on getting the chains replaced. If the chains are stretched, the problem isn't going to go away, but your warranty will.

[Sephiroth]

Looks like the layout for a roller coaster at Coney Island. Thanks for posting the picture. Is the tensioner that device that is to the right and up from the center of the front of the engine? The device with the "X" marked on it.

there are 3 independent chains. your assumption is correct, the individual bank tensioner for the right side is the one twoard the inside of the block, the one for the left side is the other one marked X on the outside of the block, and the middle chain at the bottom's tensioner is the one toward the top inside. Everything else are just guides.

[Panzer Leader]

I would insist on getting the chains replaced. If the chains are stretched, the problem isn't going to go away, but your warranty will.

Ray is totally correct. My only concern is that GM will say, "When it breaks we will fix it". Which is why I asked will the chain breaking lead to other damage. It seems that most companies today would rather replace component modules than say individual pieces. I have not noticed any symptoms of this problem. But I don't run the car hard. So I have to ask, how do you drive? Also, what may cause premature stretching of the chain? Fast take offs? Continously hitting the passing gear? Also, are there better aftermarket timing chains and tensioners available? Of course the problem with installing these is the drivetrain warranty.

[dandragonrage]

Eye spy 7 tensioners

I don't think this is correct. I think most of what you think are tensioners are just smooth surfaces for the chain to run against in order to keep the room that it takes within reason. To be a tensioner, they'd each need to have some sort of spring setup that would apply pressure.

[Sephiroth]

I don't think this is correct. I think most of what you think are tensioners are just smooth surfaces for the chain to run against in order to keep the room that it takes within reason.


there are 3 independent chains. your assumption is correct, the individual bank tensioner for the right side is the one twoard the inside of the block, the one for the left side is the other one marked X on the outside of the block, and the middle chain at the bottom's tensioner is the one toward the top inside. Everything else are just guides.

3 tensioners, 4 guides.

[dandragonrage]

gotcha

[Sephiroth]

gotcha

I get lazy with my typing without my coffee :sleeping:

[2QUIK4U]

If the chains are stretched to the point of causing a CEL they should be replaced under warranty no questions asked. I would take it in ASAP.

[Panzer Leader]

^100% agreement.

[harleymonster1]

Yes, new chains-water pump-hoses-belt, installed tomorrow. thanks for all the insight.

[harleymonster1]

Timing chains complete......this is how it went..... got her back today......runs better than ever.
scan system for codes. DTC P0008 and P0009 camshaft position system performance banks one and two stored. The presence of DTC P0008 and P0009 indicates a possible condition with the primary timing chain and the alignment between both intermediate sprockets and the camshaft. Removed front cover and inspect both secondary and primary timing chains. Did not find any measureble amount of play in chains. Sprockets did not seem to be worn, ( after further inspection they did find one sprocket with a crack, the root to the evil) Due to DTC's set, it was in the best interest to replace the primary, both secondary timing chains, all four cam shaft actuators and gears, crankshaft gear, both idler chain gears and all three timing chain tensioners. Replace all three timing chains, all four camshaft actuators/gears, crank grear and both idler chain gears along with all three tensioners.
Replaced water pump, and hoses, serpintine belt, new coolant and oil/filter all seals and gaskets.
....they took car as not to scratch anything and cleaned engine bay and car when they finished....losk and runs great

[Panzer Leader]

All under warranty?

[schwartz]

My engine light was on when i started it,but i just cleared the codes.I wonder if its related?

http://i336.photobucket.com/albums/n328/schwartz19/codes002.jpg

[harleymonster1]

All under warranty?

all covered ....no money spent

[harleymonster1]

My engine light was on when i started it,but i just cleared the codes.I wonder if its related?

http://i336.photobucket.com/albums/n328/schwartz19/codes002.jpg

do you have on-star? as you know they can give a little more info. on the codes, they we very helpful in my case...as stated before i had many codes but the honed it down to the chains and sprockets. The dealer did charge me $45 when they first could not find the problem but have since credited my account after the fix.
don't fool around with second guessing...get it checked.

[schwartz]

do you have on-star? as you know they can give a little more info. on the codes, they we very helpful in my case...as stated before i had many codes but the honed it down to the chains and sprockets. The dealer did charge me $45 when they first could not find the problem but have since credited my account after the fix.
don't fool around with second guessing...get it checked.

I'll get it checked after the car show on sunday.Thanks.

[victory12]

The LY7 System is much more complicated. OP if you have a LY7, I would not hesitiate to take it into the dealer. Eye spy 7 tensioners and 3 chains in this picture.
http://i989.photobucket.com/albums/af16/puppabriggy/P7060030.jpg

you should know! D= you posted in this thread
http://www.g8board.com/forums/showthread.php?p=586251
WOW !!!!!!!! That's just sumthin looooking to come aaaaaparrrrt.