Engine making loud knocking noises on startup :(
Thread Starter
Member
Joined: 09-23-07
Posts: 216
Likes: 1
From: Whitby, Kanada
I wouldn't blame it specifically on the tensioner 
I had a cracked piston ring, causing fuel to get into the oil. This makes the oil super runny (it was like water even though I had just changed it when I had the tensioner replaced) which means that it can't push on the tensioner properly to keep pressure on the cam chain. This runny oil also causes your bearings to wear faster, and eventually they wear so much your car isn't able to keep proper oil pressure.
So, runny oil, low oil pressure, worn cam chain and guides, etc. led to a bolt braking and all hell breaking loose under there
The mechanic said he's seen it a TON OF TIMES on cobalts?!?! WTF!!!
Gave me this print out:
They accidently put some non-hardened parts in the automatic feed hopper that our engines get built with!??!
WHAT THE ****!
Looks like I'm calling Sarah from GM back!! I asked her about ANY service bulletins or recalls on my car, and she said "nope", but my f'ing mechanic can just print this out??
Will be interesting to find out what date my engine was built...
EDIT: Says built 11/2006 on the door sticker! hmmmmmmm.
-Jamie M.
I had a cracked piston ring, causing fuel to get into the oil. This makes the oil super runny (it was like water even though I had just changed it when I had the tensioner replaced) which means that it can't push on the tensioner properly to keep pressure on the cam chain. This runny oil also causes your bearings to wear faster, and eventually they wear so much your car isn't able to keep proper oil pressure.
So, runny oil, low oil pressure, worn cam chain and guides, etc. led to a bolt braking and all hell breaking loose under there
The mechanic said he's seen it a TON OF TIMES on cobalts?!?! WTF!!!
Gave me this print out:
Originally Posted by GM
AIP3252
MODELS:
2006-2007 CHEVROLET COBALT, COBALT SS
2006-2007 CHEVROLET HHR
2006-2007 CHEVROLET MALIBU
2007 PONTIAC G5
2006-2007 PONTIAC G6
2006 PONTIAC PURSUIT(CANADA ONLY)
2006-2007 PONTIAC SOLSTICE
2006-2007 SATURN ION REDLINE
2007 SATURN SKY
BUILT BETWEEN 4/1/06 - 11/1/06
WITH ANY OF THE FOLLOWING ENGINES
2.0 ENGINE (VIN P - RPO LSJ)
2.2 ENGINE (VIN D OR F - RPO L61)
2.4 ENGINE (VIN B OR P - RPO LE5)
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
CONDITION/CONCERN:
On rare occasions, a tick or rattle noise may be heard from behind the front cover of the engine and/or pieces of a timing chain roller may be found during an oil change. This may be the result of a timing chain concern.
Non-heat treated timing chain rollers were randomly installed in the assembly line hoppers. He advised that this happened sometime between 4/1/06 - 11/1/06 so it can randomly affect late 2006 - early 2007 models.
RECOMMENDATION/INSTRUCTIONS:
If this concern is experienced, inspect the timing chain for missing or damaged timing chain rollers. If a missing or damaged timing chain roller is found, replace the timing chain and gears using the part numbers currently listed in the parts catalog.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
MODELS:
2006-2007 CHEVROLET COBALT, COBALT SS
2006-2007 CHEVROLET HHR
2006-2007 CHEVROLET MALIBU
2007 PONTIAC G5
2006-2007 PONTIAC G6
2006 PONTIAC PURSUIT(CANADA ONLY)
2006-2007 PONTIAC SOLSTICE
2006-2007 SATURN ION REDLINE
2007 SATURN SKY
BUILT BETWEEN 4/1/06 - 11/1/06
WITH ANY OF THE FOLLOWING ENGINES
2.0 ENGINE (VIN P - RPO LSJ)
2.2 ENGINE (VIN D OR F - RPO L61)
2.4 ENGINE (VIN B OR P - RPO LE5)
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
CONDITION/CONCERN:
On rare occasions, a tick or rattle noise may be heard from behind the front cover of the engine and/or pieces of a timing chain roller may be found during an oil change. This may be the result of a timing chain concern.
Non-heat treated timing chain rollers were randomly installed in the assembly line hoppers. He advised that this happened sometime between 4/1/06 - 11/1/06 so it can randomly affect late 2006 - early 2007 models.
RECOMMENDATION/INSTRUCTIONS:
If this concern is experienced, inspect the timing chain for missing or damaged timing chain rollers. If a missing or damaged timing chain roller is found, replace the timing chain and gears using the part numbers currently listed in the parts catalog.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
WHAT THE ****!
Looks like I'm calling Sarah from GM back!! I asked her about ANY service bulletins or recalls on my car, and she said "nope", but my f'ing mechanic can just print this out??
Will be interesting to find out what date my engine was built...
EDIT: Says built 11/2006 on the door sticker! hmmmmmmm.
-Jamie M.
Last edited by toysareforboys; Aug 17, 2012 at 03:54 PM.
Junior Member
Joined: 12-13-11
Posts: 420
Likes: 0
From: Wisconsin
Damn, that sucks, and I wish I would have been watching sooner, I would have suggested you get a complete timing kit off crateenginedepot. But the thing I don't get is their is nothing fuel related around the timing set that would cause it to leak into the oil from it rubbing on something in the head without getting a bad vacumm leak. honestly, what I think the fuel was coming from cause of the miles you had on it, was when you shut off your car one or more of your injectors were leaking into the cylinder, and past the rings, could the rings have been bad, yes, but I"ve seen gas leak past either way.
But I hope you find another engine soon. and again sorry for your experience with your car
But I hope you find another engine soon. and again sorry for your experience with your car
Last edited by brian.olsson; Aug 19, 2012 at 09:53 PM.
Thread Starter
Member
Joined: 09-23-07
Posts: 216
Likes: 1
From: Whitby, Kanada
It's better to spend $1k and fix the knocking, then spend $3.5k replacing your engine
-Jamie M.
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Joined: 11-18-08
Posts: 781
Likes: 0
From: MONCTON
Senior Member
Joined: 11-18-08
Posts: 781
Likes: 0
From: MONCTON
i have a theory but this noise is actually part of the belt tensionner, but to make the noise it seems like the chain is loose because when it was really loose(bad chain tensioner) that was like 3 times as noisy. i have anew tensione in and now it makes noise on startup so i believe my chain is stretched. causing the idle pulley to not turn smoothly causing the belt to kinds jump around. does this make sense at all or im just going nuts?
It makes sense; my belt tensioner looks a little lose but it doesn't look like it will get tightened up with the bolt.... I thought it was suppose to be like that... I might have to check later
And by chain stretched u mean belt or actual timing chain?
And by chain stretched u mean belt or actual timing chain?
hope it fixes it
its the chain guides and bolts folks....good luck. CED has a package with everything for small $
I got one, try email or the fone...
I got one, try email or the fone...
Last edited by Powell Race Parts; Aug 20, 2012 at 07:54 PM. Reason: Automerged Doublepost
it could be the black guide, and the shoulder bolt that holds it breaks and the guide flops around. Or the bottom of the black guide chips and lets the chain get a little bit out of control especially on the over run (decel) I always so complete kits on rebuilds, and ZZP told me they are looking at going to an 8 mm bolt instead of a 6 mm shoulder bolt.
Thread Starter
Member
Joined: 09-23-07
Posts: 216
Likes: 1
From: Whitby, Kanada
I e-mailed you on Friday John. I haven't got a reply yet.
Here is what I sent you:
Let me know if you've got an engine for me, or if that rebuilt one on ebay seems good.
Thanks!
-Jamie M.
Here is what I sent you:
From: Jamie M.
Sent: Friday, August 17, 2012 5:38 PM
To: 'john@powellraceparts.com'
Subject: Cobalt engine swap
Hey John. My 07 Cobalt SS Supercharged engine is sick. It drinks more coolant than it does fuel (not into the oil, not externally, must be burning it), pisses fuel into the oil, and now the timing chain is going/gone (already replaced the tensioner with the updated one 2.5 months ago).
Im thinking about buying this engine: 04-07 COBALT SS/ION REDLINE LSJ SUPERCHARGED 2.0 ENGINE REMAN/REMANUFACTURED | eBay
Would you be able to swap it for me? How much would something like that cost?
Sent: Friday, August 17, 2012 5:38 PM
To: 'john@powellraceparts.com'
Subject: Cobalt engine swap
Hey John. My 07 Cobalt SS Supercharged engine is sick. It drinks more coolant than it does fuel (not into the oil, not externally, must be burning it), pisses fuel into the oil, and now the timing chain is going/gone (already replaced the tensioner with the updated one 2.5 months ago).
Im thinking about buying this engine: 04-07 COBALT SS/ION REDLINE LSJ SUPERCHARGED 2.0 ENGINE REMAN/REMANUFACTURED | eBay
Would you be able to swap it for me? How much would something like that cost?
Thanks!
-Jamie M.
Thread Starter
Member
Joined: 09-23-07
Posts: 216
Likes: 1
From: Whitby, Kanada
it could be the black guide, and the shoulder bolt that holds it breaks and the guide flops around. Or the bottom of the black guide chips and lets the chain get a little bit out of control especially on the over run (decel) I always so complete kits on rebuilds, and ZZP told me they are looking at going to an 8 mm bolt instead of a 6 mm shoulder bolt.