Hi all,

As a newbie first let me introduce myself, I have been a car nut for a long time and have been racing on road courses for several years with different cars. I am mecahnical engineer and can do most things myself in my garage and in my friends shop. I moved to States couple of years ago from Finland.

I bought my latest car, 1992 Corvette with automatic gears, as non starting car, got it started and found that it has pretty loud ticking noise coming from engine. The car runs perfect when it is cold but starts ticking when water temp reaches around 180 F.
I have tried to find the source with hoses, screwdrivers and stetoscopes from the top but I haven't been lucky yet. I'll try today from under the car. I also try to get compression tests done today.
The nature of the sound might be described best as leaking exhaust manifold, fairly loud, but I havent been able to find the leak from them when checked with stetoscope.

Could there be leaking intake gaskets? Maybe underneath the intake manifold?
Cracked head?
Valve goes out of adjustment when warmed up and leaks?
Head gasket? (oil and water do not mix)
Other ideas or procedures to fid noise?

No V8 experience here, just 4-bangers.

Thank you in advance

hrk
1992 Corvette
1991 Miata
1986 Porsche 944 Turbo
1976 Porsche 924 with Turbo engine

 

Welcome to the forum!

LT1s are notorious for ticking fuel injectors, so that is the first thing to check. It's normal and harmless.

I suppose after that, you could check for loose rockers, bad lifters?

 

LT1 engines during that year and a few others always have a ticking sound which sounds like a lifter or lack of oil getting to the top. This however is normal unless of course you know your leaking oil serverly somewhere.

 

99% sure it's just the fuel injectors ticking. It's harmless and normal

 

First off, welcome to the forum.

I'll agree with the above in that ticking injectors is a normal condition. I chased that sound for some time after I bought mine. However, I would check the valve adjustment and push rod conditions just to be on the safe side.

 

Thanks for quick answers!

Have listened through injectors and while they differ on their sound a bit, none of them is as loud as the sound which worries me.
It definetly sounds like it ticks once in each revolution, loud enough to be heard from inside the car while driving and definetly loud enough to be heard from outside even when hood is closed. There is something going on in the engine which shouldn't be. Leak or mechanical problem, sound more like leak like "tsih". I will check under rocker covers if there is anything clearly visible there, at least I can fix the valve cover leak which I found while pouring oil into engine, made a mess on top of header...

Keep them coming

 

I'm not an LT1 guy, but I did stay at a Holiday Inn one time :lol:

I'm thinking the classic sound of a lifter hanging up...........maybe run a few oil changes thru it and see :confused:

 

Thanks

I lifted the car on ramps and tried to listen the tick, it sounds pretty similar on everywhere around the block, no solution there.
I opened valvecovers startedt the car and voila, sixth rocker in drivers side (intake) is much louder than others and syncs to the tick heard from outside.
Switched the rocker arm with the next one, adjusted while running, but the tick stayde in original place.
Any ideas how to proceed?
I was thinking getting engine once more warm, checking compression if possible in cramped area and then take intake manifold off to see lifters.
Can I do something for the lifters without taking the intake manifold off?
Is possible to remove cam while engine is in car?

Thanks for all your help!

 

The ticking in 1992 LT1's in a common and known condition. Although yours sounds like its more then the average '92 tick. However, it is important that you udnerstand the '92 tick before proceeding. Shortly after the release of the 1992 corvette many service departments got visits from worried vette owners that something was wrong with their engine because they heard a tick at warm idle.. (which usually was just normal engine noise comming from the valvetrain). To help insulate the noise from the outside in 1993 GM installed composite valve covers on the LT1's instead of the metal valve covers the 1992's have (hence why your valve covers are silver and the post-1992 valve covers are black). This helps alot.. but many LT1 owners still hear a tick.. just not as bad as the '92 model year..


now with your problem.. it seems as though you've isolated it down to one cyl. (#6).. most likely you have a lifter with a bad seal that bleeds down and doesnt stay pumped up..You could try changing the oil a few times at short intervals.. (some might even recommend a oil flushing agent be added). However, access to the lifters in not that difficult in these engines and can be gained in a few hours (removing the intake manifold). If it is as loud as you describe it would drive me nuts.. probably causing me to replace the lifter..

good luck!

 

Sounds like you've narrowed it down to that lifter :cheers:
About the only way to (maybe) save it is to take an additional half turn on it and run some flush thru it a few times.........make sure you don't hammer it while it's a little tight. Run the freeway an hour out and an hour back to maintain oil pressure, then do an oil change........do this 2 or 3 times.
If the little piece of debris doesn't dislodge, you gotta live with it or replace it :yesnod:

 

For what it is worth (not much I'm sure)
I have had very good luck using Marvel Mystery Oil, to free up a stuck lifter.
An older gentleman showed me this when I was about 15yrs old and it has proven itself to work many times for cars that have been sitting in someones yard for long periods of time. Add about 1/2 quart to the oil and drive it for about an hour or so and then change the oil. It can't hurt and it only cost a few bucks to do. :auto:

 

Welcome to the forum :cheers:

 

I agree with the ticking injectors,but I didn't think you adjust the valve train.

 

two causes of ticking with that particular year:
1. the vavle train, check for loose lifeter and adjust
2. the injectors, this was noted as a major concern for owner's in 92. it was considered as normal operation..good luck in determining your problem!

 

Welcome hrk,

Good luck finding the problem.

Any chance it might be a small exhaust leak at the exhaust manifold?

 

I still think it is collapsed hydraulic lifter. When oil is warmed up it escapes and lets lifter collapse before moving valvetrain, once it bottoms it may make that ticking sound.
Compression on that cylinder was 208 and one next to it 194 psi.

I went ahead and bought intake manifold gasket set and a lifter. Anything else I should get before taking intake manifold off?

Thanks

 

Quick update,

I took intake manifold off yesterday, repalced lifter from the valve which was ticking, and put manifolf back together.
Started the car and let it idle until water was 202 F and oil 155 F, no excessive ticking.

I did not drive or heat it up more, valvecovers needs to be attached and maybe all valves adjusted. Any pointers on that?

 

Good... I had the same question and have been worried SICK! I thought that I was in real trouble. I can hear a ticking sound that could pass for loud lifters, but the exhaust burble sounds soooo good. I don't want to believe that my engine could be in trouble. It's a Chevy small block for cryin' out loud!!! PS... I drive a '93 40th anniversary ruby. anyone else out there?


[Modified by eschoendorff, 1:33 PM 10/23/2003]

 

For what it's worth my 94 was ticking louder than normal last winter,I pulled the intake off to find #4 intake lifter completly munched,it also took out the cam[I went to the zz-4]Make sure your cam lobes are perfect before replacing lifters.As for setting vavles make a oil splash from a piece of cardboard loosen till it clacks tighten slowley till rocker goes quite,then slowly turn an aditional 1/2 turn,Mite as well check them all. :cheers:

 

[QUOTE=JasonL;1545421203]Welcome to the forum!

LT1s are notorious for ticking fuel injectors, so that is the first thing to check. It's normal and harmless.

. How loud usually? I got a 89 camaro with 96 lt1 in it and when warm it ticks really loud. And mine is boosted