Piston Slap: Batting an Eye at B18B1 Piston Slap?

Sajeev Mehta
by Sajeev Mehta

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.

Sajeev answers:

From my googling, the Honda B18B1 is not known for piston slap but anything’s possible at this age and mileage. But that’s really not the point.

If nothing more external (so to speak) could be the source of that noise, I still wouldn’t bat an eye at the sound of pistons slapping against cylinder walls. The rate of increased engine wear is likely irrelevant, even at your mileage: there are too many variables at 21 years and 260,000 miles, provided you keep those oil changes coming!

Drive the wheels off that Integra and love every minute of it. Then restore it into a street cruiser/weekend toy, as I’d regret selling such a loyal soldier for next to nothing.

What say you, Best and Brightest?

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Sajeev Mehta
Sajeev Mehta

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  • Eddy Currents Eddy Currents on Feb 10, 2018

    When the noise is present, pull one injector wire/ignition coil at a time and see if the noise is affected only for one cylinder. If all are the same, I'd just drive it. Don't thrash it till it warms up. Please note, sometimes an overheat will damage pistons. Not sure how sensitive Honda is to this.

  • SPPPP SPPPP on Feb 12, 2018

    You're planning to get 360,000 miles out of this engine without a rebuild? You are very optimistic. It might happen, but don't be surprised if it doesn't. Are you sure the noise isn't related to valve lash?

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