Rep Power: 0

I have a 1998 civic lx and when the engine is cold(first start up) the valves tap...The motor runs fine and has no oil leaks or other apparent issues. It just has a valve tap until the motor heats up a bit.. Is there something I can do or use(an additive, etc...) to fix or help this issue.. thnks TG

 
Rep Power: 518

It's not the valves.

If it goes away as the engine is warmed up, it's fine.
It's usually just piston slap.
No, you can't do anything about it.
Most of them seem to do it to some extent.

The aluminum pistons are small when they are cold (that's when the noise happens as they rock in the bore) then they grow to fit the hole as they heat up and the noise goes away.

They are machined to be correctly sized at operating temperature.


HTH

 
Rep Power: 204

thanks for this info.

I've wondered about that for a while now.

 
Rep Power: 0

Yes there is something you can do. If you have feeler gauge of 0.010Inch You could check your Valve lash. It 90% of the time the cause and this happen when engine Cold. The adjustement of valve has to be done while the engine is cold too.

If your car has more than 120k Miles it something you have to do.

Can increase your car performance if they decrease with time and will increase your mileage with a tank if the lash was too big.

But its important to respect the spec. It should be under the hood on the Catalytic Sheet under the Tab Valve Lash.