might have a problem

[dallasb84]

b18 ls build

when my car idles it makes almost a rod nock noise..... but from what ive read its just piston slap.

i have standard sized je pistons in a standard bore ls


when rpms go up the noise goes away and the motor sounds just fine....

but at idle it sounds a little like a tdi vw..


just a bit worried but hell its pretty much made this noise for the first 500 miles or so that ive put on the build so far....



anyone have similar experience with this

[CaTcH22]

Probably piston slap. Piston is just a little loose. My car does the same thing. Like a diesel rattle. Ive been driven it for 3 years now with no problems. :goodjob:

[dallasb84]

thats man

[crashtke]

Eh, piston slap SHOULD go away when it warms up. It is just caused by the loose tolerances of forged pistons when they are cold. Once it is warm it should go away if the engine was properly assembled. That is why when we build an engine for someone we always recommend bore matching and going a little over (10 or 20 over) so that the cylinders can be matched EXACTLY to the necessary clearances. Drop ins are not the best thing in the world.

[dallasb84]

yeah i set mine je 2618's at 50 over which is recommended...... but some have gone 35 and siezed the block trying to run tighter tolerances....

i did some reading and on the 4g63 forums they are running 65 over and saying fuck the knock..... just as long as there ems isnt reading over 50+ on there knock sensor at above 30% throttle.... whatever the fuck that means

im guessing as long as the piston slap goes away when i press the gas im good..... which it does...

but at idle...... shes slappin away.

when she warms up it quiets down a little.... but. yeah i still hear it. kinda like a loose rocker

[crashtke]

It's not going to hurt power too much, but it will wear out the rings faster.

[dallasb84]

thats cool with me...

if i get 20k out theis motor ill be happy to tell you the truth