LT1-Lifter Noise

[Red VelVette]

I just picked up a '92 Coupe this weekend and have just noticed a ticking sound that sounds like a noisy lifter. I bought the car from the origianl owner with 35K well documented and maintained miles. I had the car checked out last week by a Chevy dealer in Orlando and everthing was clean.

I did not notice the ticking sound until I arrived home yesterday. I drove it home 450 miles and it ran great. Never even abused it on the drive back as I had my wife with me. Oil pressure is good and the oil, (Mobil 1), was just changed 3 weeks ago. Seems to run frine but the "lifter" noise has me concerned. Any ideas?

 

[bradfordsvettes]

are you sure it isn't the injectors ticking away as they meter the fuel . Some are noiseier than others but it is a normal operating sound . just a thought Steve

 

[Red VelVette]

I hope that is all it turns out to be but the sound is more pronounced than injector noise that I have heard before and the frequency changes in unison with the RPM"s.

Thanks,

 

[WhalePirot]

are you sure it isn't the injectors ticking away as they meter the fuel . Some are noiseier than others but it is a normal operating sound . just a thought Steve

That was my thought. With good documentumentation of great maintenance, don't you think lifter problems would be unlikely at 30k?

I chuckled at the "as I had my wife with me" comment.

 

[ZumZum]

I hope that is all it turns out to be but the sound is more pronounced than injector noise that I have heard before and the frequency changes in unison with the RPM"s.

Thanks,

You'd be surprised as how noisy the injectors can be and they will change frequency with the engine speed also. My bet is that it's injector noise but if your not mechanically inclined or just want a second opinion, a good mechanic could tell you in 5 seconds whether it's lifters or injectors.

 

[markone]

Here is a copy of my post on the same subject last Decmeber and Hibs reply, hope it helps:

Quote:
Originally Posted by markone
Hi everyone:

This may have been asked before but I searched the forum and could not find a specific reference to a '92. Mine has 11k on it and I notice that there is a distinct "ticking" noise (if it was a pre '90's small block I would swear it was a lifter) after it is running for a while at oper temp. It appears to be less pronounced when cold. Is there a documented problem with noisy injectors on the '92's? I was planning on running some Marvel Mystery oil in with the regular oil to clean out the lifters. If anyone has any definitve information it would be appreciated.

Thanks,

markone


The key issue here is: how loud is this ticking?

We'll assume that it's not excessively loud.

It is normal that the ticking would get slightly louder when the engine is at operating temperature.

The 1992 LT1 has a slightly more aggressive camshaft profile than do 93-96 LT1s. The difference makes little or no difference from a performance standpoint but it does cause 92 LT1s to make a little more valve train noise so, with 92s, a little more valve train ticking or clicking is normal. The change in camshaft profile was made to reduce the loudness of this clicking.

Secondly, injectors, even when working correctly, emit a little clicking noise of their own.

Lastly, from about 94 on back, C4s have a noise problem with fuel-line-hammer, however, that noise is characteristicly different than valve train noise. If you have fuel-line-hammer, it sounds like someone flicking the top of a coffee can with their finger nail....kind of a thunk, thunk, thunk, rather than a tick or click. Fuel line hammer is not easiily eliminated.

DO NOT put "Marvel Mistery Oil" or "Justice Bros. Engine Tune-Up" or any other similar additive in your engine oil. They contain oil thinning solvents which should only be used as a last resort in a very-high-mileage engine with obvious levels of sludge and dirty oil. A 92 with 11,000 miles on it will not be in that condition. Anything that thins oil is the LAST additive you want to put in an engine which already has 5W30 oil.

The best thing you can do is switch from 5W30 synthetic oil to a 10W30 synthetic and learn to like the little bit of ticking your 92 LT1 valve train makes. Also know that your 92 makes about 3-5hp more than 93-96 because of the more aggressive camshaft.

Now....if this ticking clicking is very loud then we have a completely different thread.
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Hib Halverson

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[Tuna]

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What he said!

The 92 LT1 has more valve train noise than the later LT1's. In addition to changing the cam profile some, the black composite valve covers were added to quieten the noise some - the composite valve covers act like mufflers, much more so than the metal ones on the 92. BTW, I changed mine out to the black composite covers a long time ago and reduced the underhood valve train noise quite a bit.

 

[Red VelVette]

The verdict is in...for now

I took it today to Maxie Price Chevrolet after talking with their service manager last night. He had two of his more experienced Corvette mechanics listen to it, (with stethacopes no less), and they each said that indeed it was a noisy lifter.

They said that it was certainly louder than normal but not enough to warrant a hunting expedition and that there was nothing to be concerned with. They suggested that if it gets louder or more annoying then we might need to address it and replace the offending lifter. And the best part of all is they spent the better part an hour with it and did not charge me anything!!!

So for now all is OK again, unless so of you have some other thoughts that I should be concerned about. By the way what was the other thread that Hib referred to in his article if the lifter ticking sound was louder?

 

[Red VelVette]

markone,

Did your lifter noise subside or is it still the same level? Did you do anything or leave it alone? How loud would you say yours is (or was)?

Thanks for the input!

 

[markone]

My "noise" stayed the same, and I did nothing based on Hib's response. However I only drove the car 600 miles in one year. I'm taking the positon that it is the injectors. The way I would describe the noise would be as a low ticking. If it were an older carbureted small block I would suspect a lifter, but with all of the discussion about the noisy injectors on the '92 and the cars mileage (11K) I figured I am safe.

 

[Red VelVette]

Thanks for the info. Hib's response to you and the comments of the mechanic at the dealership eased my concerns. I am not crazy about the lifter noise but I can live with it for a while. Right now I can fix it by keeping the windows up or turning up the volume on the radio!

 

[Tuna]

Corsa exhaust and you'll never have to listen to a noisy lifter again!