Broken Timing Chain - Assessing Internal Damage
Thread Starter
Pro
Joined: Sep 2002
Posts: 715
Likes: 2
From: Mooresville NC
Broken Timing Chain - Assessing Internal Damage
I started getting a cam sensor code a few weeks ago then a week ago the car quit running while my wife was driving. Turns out the valvetrain isn't moving so likely a broken timing chain. I also found a groove on the cam sensor like the cam had backed out and made contact. I removed the valve covers and intake today and found some bent pushrods and some of the valves aren't closed.
The car is a 2005 with an A&A supercharger and headers. Stock internals. I had a wobbling crank pulley about a year ago that I replaced but not sure if that could be related. I was planning on swapping the cam and putting on a smaller blower pulley while changing the timing chain.
Does this mean the valves are bent and requires head removal? Should I be checking anything else for more extensive damage?
The car is a 2005 with an A&A supercharger and headers. Stock internals. I had a wobbling crank pulley about a year ago that I replaced but not sure if that could be related. I was planning on swapping the cam and putting on a smaller blower pulley while changing the timing chain.
Does this mean the valves are bent and requires head removal? Should I be checking anything else for more extensive damage?
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
I think you're in for at least a head tear down. With bent valves there had to be piston/valve contact. Just hope you don't have to go deeper.
You might want to talk to the guys in the C6 Forced Induction Forum.
Good luck.
You might want to talk to the guys in the C6 Forced Induction Forum.
Good luck.
Thread Starter
Pro
Joined: Sep 2002
Posts: 715
Likes: 2
From: Mooresville NC
Melting Slicks
Joined: Oct 2010
Posts: 2,220
Likes: 16
From: Sugarhill Ga
god i hope you are not the person that posted pictures of the cam sensor with the groove cut into it. I had the timing gear shear of the cam without braking the chain and did tons of damage to my engine.
Thread Starter
Pro
Joined: Sep 2002
Posts: 715
Likes: 2
From: Mooresville NC
I got my heads off and found bent pushrods and valves along with small dents in the pistons from the valves. They are so small I can barely catch a finger nail in them. Advanced Induction is currently rebuilding the heads.
What scares me even more is that I got the timing cover off and found I don't have a broken timing chain. Turns out all three cam bolts broke off. I'm trying to figure out what could cause this and it the cam being able to move around for a few seconds would cause any other issues.
Should I just put a new cam and the rebuilt heads back on and hope for the best or should I go ahead and pull the engine and have it rebuilt?
What scares me even more is that I got the timing cover off and found I don't have a broken timing chain. Turns out all three cam bolts broke off. I'm trying to figure out what could cause this and it the cam being able to move around for a few seconds would cause any other issues.
Should I just put a new cam and the rebuilt heads back on and hope for the best or should I go ahead and pull the engine and have it rebuilt?
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Pro
Joined: Aug 2009
Posts: 517
Likes: 25
From: Westchester NY
Join the club of the cam gear bolts backing out. Mine did not fully come out but came out enough to hit the timing cover, take the sensor with it, take the dowel out of the cam and that fell into the oil pan, took out the cam due to the movement and took out the lifters. Definitely check your lifters and your cam for wear.
Burning Brakes
Joined: Mar 2006
Posts: 891
Likes: 18
From: Dayton Ohio
Join the club of the cam gear bolts backing out. Mine did not fully come out but came out enough to hit the timing cover, take the sensor with it, take the dowel out of the cam and that fell into the oil pan, took out the cam due to the movement and took out the lifters. Definitely check your lifters and your cam for wear.
Matt
Thread Starter
Pro
Joined: Sep 2002
Posts: 715
Likes: 2
From: Mooresville NC
Mine didn't back out... they actually broke off even with the cam. I need a new clutch anyway so I'm leaning toward pulling the engine and having it rebuilt and maybe throwing some forged pistons and rods in there.
Pro
Joined: Jun 2005
Posts: 693
Likes: 2
From: Los Angeles CA
My 05 did the same thing last year. Thought it was broken chain but shop found broken bolts. Had them do a head n cam on it since might as well.
Did not rebuild bottom end, but they did remove oil pan to make sure all clean no debris.
Did not rebuild bottom end, but they did remove oil pan to make sure all clean no debris.
Burning Brakes
Joined: Mar 2006
Posts: 891
Likes: 18
From: Dayton Ohio
Matt