Did a compression test to my car today , and compression at cylinder 8 was equal to zero , so what do you think guys, a damaged valves or a burned a piston?

any advise what to do next ?

 

Well, what exactly happened? Oversped the engine? Went lean on the bottle? I would pull the head and see what happened. If it is an engine oversped or too much nitrous you probiably knocked a hole in the slug or bent a valve if it is a oversped deal.

 

Guesses are useless at this point. Pull the heads and check it out.

 

Thats what happen to me
https://ls1tech.com/forums/generation-iii-internal-engine/445285-opps-blowed-something-my-engine.html

well I need to pull the engine to get the heads of!??!

 

Hole in piston or broke at the ring lands.

 

do I need to pull the engine guys ?!??!

 

Pull the heads with the motor in the car first. It might just need a new set of heads or have your current set reworked. You might have gotten lucky. No smoke leads me to think no ring problems or holes in the pistons. You probiably just bent the **** out of a valve or two.

 

Start with the #8 valve cover.

You don't need to pull the engine to fix a valve problem.

 

Mine did the same thing, check for bolts in the exhaust that were left in the intake due to warrenty work done by a Dealership......

 

Guys I am little confused in here , How hard is it to pull the cylinder heads ? I took my car to a very known mechanic with ls1`s and said that he must pull the motor in order to fix the problem ?? and I was like what the **** is going on?

what do u think guys??

 

difficulty varies with experience and how mechanically inclined you are.

http://www.ls1howto.com/index.php?article=2 . Deals with a head & cam swap, but you're just doing a head or two, which is less work. Skip the parts that don't pertain to you.

Buy a service manual. I don't trust torque specs "on the net", but this site may be good for it. I don't know for sure.

 

ls1howto is very accurate on all of their numbers, you can trust it. I used it for my first cam swap a while back, had every detail you could think of explained. It is very easy to pull the heads with the motor in the car.

 

I am not sure what this mechanic is trying to do !!

 

Stick it to you where it hurts!

 

Before you pull anything apart buy or borrow a leakdown gauge and see if it's actually a valve or piston problem. Make sure you roll that cylinder up to TDC on the compression stroke. Listen for where the air escapes. It will be out the intake, exhaust, radiator or crankcase.

There is no reason the remove anything until you know what to look for.

 

I agree, a leakdown will narrow your search. It will also let you know if maybe you botched the compression test. Assuming you didn't check, double check, and re-check your results.

 

check your pushrods too... i broke one of mine off, and it did the same thing on a compression test. Also, mine didnt make a ticking sound after it actually broke, it just ran rough, and made the SES come on.

 

Do you have blowby? Pull the oil fill cap witht he car running. Then stick your hand over the hole, if you feel a pulsing and smell oil, choo-choo effect, then plan on a shortblock. Otherwise look at the heads.

 

Just wondering out loud here. Did you make sure both valves are actually closed before doing the compression check????


Checking for a bent valve can be very easy. Pull the valvecover, then pull both rockers off for piston 8. If both valve and spring assemblies are not all the way back up you've bent a valve. You may have to pull some other rockers to compare the height of the springs to the ones on your problem #8.

 

thanks for the input guys , i will do what u all mentioned above , and re-compression test one more time .

i will tell what will happen tomorow.