Koby

A while back I posted that my car sounded like deisel when it was colder outside, and many people said that it was piston slap. I was unable to get a video or sound clip of it, but now it sounds like that constently. So my question is....could it be an exhuast leak? The sound is constant, it never goes away. Some days it is worse then ever, but it is always there. Any thoughts?

TraceZ

I bet it is rod knock.

Does it do it cold? hot?
What oil pressure do you have cold and hot?

1SlowFormula

list your mods...

Also have you been driving it since this started? How many miles?

If you have been driving it and have put decent miles on it then I wouldn't think a rod. It could be something simple like the AIR system hose broke. I had gone through 2 AIR tubes on the pass. side before I decided to !AIR. And each time it broke there was a loud tapping/knocking sound coming from it that increased with RPM...

Koby

It does it all the time. It is worse when it is cold, but it is always there. Doesnt matter if it was 90 degree outside and the car was at 180, it would still make the sound. My oil preasure hasn't changed since I bought the car. Cold it is normally around 60psi and then warm it falls normally around 40 psi or a little higher. I have noticed this since december and probably put around 2k or a little more miles on the car. I haven't noticed any performance drop, just the sound is annoying and I want to fix it.
The car idles around 500rpm, no hesitation. Still runs pretty smooth.

Current mods include:
LT4KM, !TB, !Air Silencer, !AIR, 180* thermo, Moroso CAI, Hooker Catback exhaust, MSD Coil, NGK Spark Plugs, Accell 300+ Wires, 85MM Z06 MAF, Prothane front and back endlinks, front and back bushings, Tranny mount, LCA'a, Panhard Rod, Strut Tower Brace, and Subframe connecters.

Guest47904

Check your coolant level, my Vortec did that and it was the intake gasket leaking coolant into a cylinder until the intake expanded and sealed up after getting warm.

If you need a reference point, fill both the radiator and the overflow resevoir and check them after a few days.

You could also do a leak down test and check the radiator for bubbles or you could pressure test the coolant system.

Koby

I have tested the cooling system already this year, and it doesn't leak any water. It has been running a bit warmer than normal, but I havne't noticed a decrease in coolant level, or any coolant in the oil. I am pretty sure that is just a thermostat issue.

Angelis83LT

Thank you for posting that.. I just found my annoying tapping sound on my 84z28 lol