Piston Slap: Yes, another question about piston slap

To get things started, here’s an update from Tito and the problem with his Corvair:

I finally had the time to get the Corvair up in the air, and sure enough, looks like I have some bushing replacement in my future. Steering linkage all looks good. The boots on the ball joints are torn, but otherwise they seem fine. However, the bushings throughout the front suspension are in varying levels of squished-out and cracked-up.

Every time you think you’re done spending money for a while, the car begs for another few hundred! (I know that’s right! – SM)

And now to our regularly scheduled programming:

Calvin writes:

I have a Acura 1.8L engine that overheated and now has piston slap. Is this bad, or can I just drive it until it is time to replace the engine? The car runs fine except for the slapping sound.

Sajeev answers:

As we’ve discussed in the past, piston slap is usually more of an annoyance rather than an issue compromising engine performance or durability. But I am a little concerned it happened after an overheating incident. Does that sound go away at engine speeds above idle?

Calvin:

It lessens with driving but the slapping sound is always there.  The slapping was there when I bought the car with 120K miles on it, however it went away when the car warmed up. I put 30K miles on it before it cooked the head gasket.  Head was warped; it was replaced as well. I have also replaced the rod bearings, thinking that it was a rod knock. I am wondering if it might be a wrist pin problem.

Sajeev:

Wrist pin knock is entirely possible, especially since you don’t know how well maintained it was before your purchase at 120K miles.  While I have never tested this following piece of advice, it wouldn’t hurt to disconnect a spark plug wire lead one at a time, and see if the wrist pin noise goes away.  If nothing changes, maybe it is just a case of piston slap.

Considering this information, especially the fact that the short block has 150K on the clock, just keep the oil changes coming at appropriate intervals, and drive your 1.8L Honda product until the motor dies. And if this is a hot commodity like an Acura Integra, installing a fresh motor will probably bring you affordable enjoyment and increase its resale value.  Which is always a nice pairing, if you own a vehicle desirable enough to make the numbers work. As a Lincoln-Mercury fanboy, I wish I knew that feeling … but I digress. 

There’s little doubt that you can safely (so to speak) drive that motor until it dies. And odds are that failure will likely happen a long time from now.