#B18b1PistonSlap

TTAC commentator PandaBear writes:

Hi Sanjay, (First Sanjeev, now we’re using my brother’s name? – SM)

I have a ’97 Acura Integra RS on which my mechanic recently did a top end rebuild. The radiator got stuck closed and somehow created a vacuum in the cooling system, overheated and warped the head. Soon after the rebuild a new grinding noise started and the mechanic isolated it to a failing water pump bearing. Before the rebuild my car had a noise that I thought might be exhaust or valvetrain related, but ended up being the failing water pump. After the water pump was replaced the car is a lot quieter, and because it is a lot quieter, I’m now hearing cold start piston slap that I never heard before.

The cold start piston slap seems to remain till the engine is completely warmed up. It seems to come when the outside temperature is about 50F or lower. The car has about 260k original miles and is in OK condition, and I’ve replaced the ignition coil, radiator, axles, struts / shocks, hoses, oil pan gasket, so far so it actually drives OK for its age (kind of hard as the bushings are old). How much should I worry about the piston slap if all I care is durability of the engine? My goal is to daily drive another 5-10 years and 100k miles out of it if possible without a rebuild or an engine swap.