Hey guys i just bought a 99 tahoe the guy i bought it from had the engine built by a pretty reputable shop. When its cold it makes a wierd knocking kind of noise but goes away when warmed up it also has a lifter tickonce it gets warmed up i called the builder and asked him and he told me to run 15w40 so i did and it helped but did not completely go away. Other than the noise it runs great and has tones of power.

 

I'm only making guess but the cold knock sounds like piston slap that goes away when warm.

The lifter tick will be far louder if you have headers. Iron manifolds will dampen the sound a lot.

 

Thats what the seller told me and after driving it i asked about the lifter tick and he said he didnt know. So the piston slap is normal? He didnt know the numbers but this engine has a bunch of torque. It runs great but the cold start noise worries me a bit. Its not so bad on warmer days

 

I run a fresh stroker in my current setup and indeed there is startup piston slap given the nature of the makeup of the stroker. If you're in a warmer climate I would suggest running ZR1 Racing Oil in 20W50 (non synthetic). Makes a world of difference in a stroker motor. Helps keep the lifters pumped as well.

 

I live in the dfw area. When its 70 outside there is almost no noise on startup but once it reaches operating temp there is a ticking noise that Sounds like a lifter tick i chabged the engine oil to rotella 15-40 after talking with the builder and it has helped. I just wanted to know if the piston slap was normal. This engine only has about 20k on the clock. Ill try that oil on the next change.