Piston Slap: Is It Piston Slap? Ja-nee, Baby!

Sajeev Mehta
by Sajeev Mehta
piston slap is it piston slap ja nee baby

Mu-een (from Cape Town, South Africa!) writes:

Hi I would like to know what is the difference sound of a tappet noise, or bad rocker, or a piston slap. Thanks regards.


Sajeev answers:

I suspect that –for most engines– piston slap is a deeper, more resonant sound than an out of whack tappet. Pistons are bigger and buried further in the engine (usually) than tappets, it’s gonna have a different sound by design. Conversely, you could easily isolate the two sounds with a decent mechanic’s stethoscope, or with a cheap one. So for whatever vehicle you own down in Cape Town, try isolating the noise with a stethoscope…or maybe just a loooooong screwdriver against the cam/valve cover on the top of the motor.

Now on to the important implications of this letter. Put another way, OH MY DAMN SON U KNOW WHAT THIS MEANS? We got us some Piston Slaps from North America, South America, Europe, Asia, Australia…and now Africa!

TTAC RULEZ THE WORLD! This is Panther Love with an LSX-FTW swap: a fantastic combination of wonderful things in a singular moment.

Wait…is Antarctica a continent too?

AND they drive cars down there?

Do they read TTAC?


We were sooooo close to world domination!

Send your queries to sajeev@thetruthaboutcars.com. ESPECIALLY IF YOU ARE FROM ANTARCTICA. 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.

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3 of 14 comments
  • Peter E. Puffington IV Peter E. Puffington IV on Apr 16, 2013

    They all sound like a large woosh coming from your wallet.

  • Raph Raph on Apr 16, 2013

    LSx swap into a pather! Have the gods no mercy!!!! That ain't panther love. Panther love would be FRPP 5.0 MOD block with a stroker crank making it dang close to 330 cubes topped off with a set of Trick Flow 2v heads and a nice set of cams. I swear if I ever get a heap of money, I'm doing a road-runner(Boss 5.0) MT-82 and 8.8 swap into a nice old 67 Nova.

    • JaySeis JaySeis on Apr 17, 2013

      I'm with you and I'd cram an FE in into say...a C4 'Vette. Maybe a solid front axle just for fun.

  • Redapple2 Barra at evil GM is not worth 20 mill/ yr but dozens (hundreds) of sports players are. Got it. OK.
  • Dusterdude @SCE to AUX , agree CEO pay would equate to a nominal amount if split amongst all UAW members . My point was optics are bad , both total compensation and % increases . IE for example if Mary Barra was paid $10 million including merit bonuses , is that really underpaid ?
  • ToolGuy "At risk of oversimplification, a heat pump takes ambient air, compresses it, and then uses the condenser’s heat to warm up the air it just grabbed from outside."• This description seems fairly dramatically wrong to me.
  • SCE to AUX The UAW may win the battle, but it will lose the war.The mfrs will never agree to job protections, and production outsourcing will match any pay increases won by the union.With most US market cars not produced by Detroit, how many people really care about this strike?
  • El scotto My iPhone gets too hot while using the wireless charging in my BMW. One more line on why someone is a dumbazz list?