Piston Slap: Niedermeyer Dumps the Clutch. Actually, No.

TTAC’s very own Paul Niedermeyer writes:

I bought my ’05 Scion xB two years ago (used) with 15k miles. Perfect condition; mommy driver. Within a couple of weeks, I started hearing a chirping sound when the clutch was not engaged (pedal up); it stopped as soon as I put some pressure on the pedal. Bad throw-out bearing! Dealer confirms, replaces bearing, resurfaces flywheel, and throws in a new clutch as “goodwill gesture.” I’m very happy with how I was treated (it was under warranty, of course). They tell me these bearings hardly ever fail; I must have gotten a fluke bad bearing.

Fast forward two years: (now) and another 15k miles. The chirping is BACK!! Exactly in the same time frame (two years) and mileage (15k miles). I’m a fanatic about not riding the clutch pedal. Never abuse the clutch. I intend to keep this car for the long haul. And now the warranty is out (clutch not covered by powertrain warranty). I’m going to try to negotiate something with Toyota.

My question: It utterly defies my understanding and logic for this to happen. I can’t come up with an explanation. Is it possible that there is something (weird) about my car that is causing this, like in the (hydraulic) linkage, or??? If this is going to happen every 15k, I gotta get rid of this car, which I don’t want to do. Can anyone offer me an explanation? Something to use as leverage with Toyota?

Sajeev answers:

Holy karmic retribution, Batman! I had better play nice with the Lincoln MKS lest my land yacht also face an ironic mechanical malaise.

Like you said, the connection between the clutch and the clutch pedal is the suspect. Since it’s hydraulic, I’d look at the master/slave cylinder. From what (little) I know about these systems, they are either self-adjusting or have very few adjustment points.

So verify what can be adjusted then check if the cylinder is moving when you push on the clutch pedal. Maybe it’s clogged (from contaminated fluid) and needs to be replaced? Or the system needs to be flushed? No matter, you are on the right track.

I am very interested to hear from the B&B on this, as TTAC’s own 24 Hours of LeMons car (a 1973 Datsun Z) has a similar clutch engagement problem.

[Send your techno-mechanical queries to sajeev.mehta@thetruthaboutcars.com]