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Old 10-06-2011   #1
oricale
 
Join Date: Oct 2011
Location: STAFFORD VA,
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Default NEED LT5 TIMING FAIL HELP!!!!

Hello,I have purchased a ZR1 that had a timing belt jump on the passenger side and now it sounds like a diesel on one side,..apparently it runs,...we had it compression checked and leak checked with NO issues,..My question is

*will I need to tear down the Head to see if there was any damage?
*would there be any damage if the timing chaing jumped?
*would it be best to do a Valve/Timing chain job on both sides
*what benefits could I gain if I had the to do a valve job on both HP wise?

THANKS FOR ANY INPUT!!
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Old 10-06-2011   #2
A26B
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

Quote:
Originally Posted by oricale View Post
Hello,I have purchased a ZR1 that had a timing belt jump on the passenger side and now it sounds like a diesel on one side,..apparently it runs,...we had it compression checked and leak checked with NO issues,..My question is

*will I need to tear down the Head to see if there was any damage?
*would there be any damage if the timing chaing jumped?
*would it be best to do a Valve/Timing chain job on both sides
*what benefits could I gain if I had the to do a valve job on both HP wise?

THANKS FOR ANY INPUT!!
There is no timing "belt' on the ZR-1 Corvette LT5 engine. It uses chains to drive the cams.

If indeed this is what happened, you will most definitely need to remove the cam cove to inspect. Cam chains do not "jump". It could be a broken cam sprocket bolt, broken cam, broken chain.

It needs to be inspected by someone with bonafide knowledge & experience with the LT5 engine. Where are you located? We can probably direct you to the closest service.

No Hp gain from a valve job if it was Ok before. There are a number of performance enhancement modifications that could be done at the same time as the repairs. Depends only on the depth of your pockets.
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1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc.
2016 Black-Red, 3LT-Z51 Auto 8-speed.
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Old 10-06-2011   #3
oricale
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

Hello,..yeah I meant chain,..here is a pic of the head with the cam cover off:

,..chains are tight still as I could tell,..apparently this happend at idle and they shut if off when it started to sound like a diesel engine,..I live in washington DC..

From what I gathered they just dont have the knowledge to identify what actually happend,..
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Old 10-06-2011   #4
Pete
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

Quote:
Originally Posted by oricale View Post
Hello,I have purchased a ZR1 that had a timing belt jump on the passenger side and now it sounds like a diesel on one side,..apparently it runs,...we had it compression checked and leak checked with NO issues,..My question is

*will I need to tear down the Head to see if there was any damage?
*would there be any damage if the timing chaing jumped?
*would it be best to do a Valve/Timing chain job on both sides
*what benefits could I gain if I had the to do a valve job on both HP wise?

THANKS FOR ANY INPUT!!

Chains do not/can not skip/jump in our Z's unless there was a whole lotta of other issues.
Since your comp/leak tests good not the chains or cam timing.
Check for a miss.
I'm thinking your hearing flywheel/trans rattle or have a bad lifter which is very rare.
Most common issues for a miss injectors,wires,coils,check/change plugs easy and cheap.

Pete
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Old 10-06-2011   #5
Kevin
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

was it a backfire?
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Old 10-06-2011   #6
oricale
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

I wasnt there thats the problem,..they took the cover off and did the leakdown and compression found nothing,...cant fire it up due to that,..but they said it was at a low idle when popped and started sounding like a diesel...(their words...not mine)...so i am trying to figure our the best way to move forward,..but at this point i just want to make sure that no damage can or did happen to the block or anythign i cant fix or have fixed,..any ideas?
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Old 10-06-2011   #7
Kevin
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

Quote:
Originally Posted by oricale View Post
I wasnt there thats the problem,..they took the cover off and did the leakdown and compression found nothing,...cant fire it up due to that,..but they said it was at a low idle when popped and started sounding like a diesel...(their words...not mine)...so i am trying to figure our the best way to move forward,..but at this point i just want to make sure that no damage can or did happen to the block or anythign i cant fix or have fixed,..any ideas?
yeah, get the car back, have the dc zr-1 crew look at the car, DON'T LET SOME JAGOFF AT A DEALER WORK ON IT
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Old 10-06-2011   #8
secondchance
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

May I ask where the car is at? Call me at 703 980 8814.
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Old 10-06-2011   #9
oricale
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

i also would like to know how to check/reset timing of the cam chains
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Old 10-06-2011   #10
Pete
 
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Default Re: NEED LT5 TIMING FAIL HELP!!!!

Quote:
Originally Posted by oricale View Post
i also would like to know how to check/reset timing of the cam chains
Have them stop all work put the valve cover back on with anerobic sealent,make sure you clean the surfaces good head & cover.

They will do more damage then you will be able to afford $$$ seen it too many times these techs think they know everything at your expense/loss this is not what they are use to it's not a small block chevy they hear a rattle and start taking things apart what the hell was he looking for rocker arms,has no clue about the motor/trans design freaking shmucks instead of manning up and saying i have no clue they start taking sh!t apart WTF.

Do not atempt to retime the cams it's impossible with the motor in the car.
JUST PUT THE VALVE COVER BACK ON.

Look at the MAP sensor at the back of the plenum make sure the vacuum hose is connected very common they blow off.

Like i said before most common are injectors,wires,coils.
Go to common issues/solutions.

Pete
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'91 #1635 PoloGreen 350 LT5
11.09 @ 129.27
11.04 @ 128.86
474RWHP 400RWTQ
http://www.youtube.com/watch?v=SFNFOhGGlR4
http://www.youtube.com/watch?v=ZlRIOMwaDYY
https://sites.google.com/site/peteszr1garage

Last edited by Pete; 10-06-2011 at 01:52 PM.
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