Piston Slap: a Camry Car Wash Conspiracy?

Scott writes:

Dear Sajeev,

Recently I took my 1999 Toyota Camry (2.2L 4-cylinder) to a touchless car wash with underbody sprayers. This was a car wash that I used often, so I had good luck with it until this one particular day. Prior to getting it washed the Camry ran fine all afternoon, including during the wash.

However, after I left and drove about a quarter-mile down the road, the car acted funny–running rough, no power, etc. This happened sporadically, so one second it would “act up” and then it would run normally for another half of a mile and then “act up” again. As I was trying to nurse the car along to get me back home, the check engine light came on and the hiccups became more frequent until it ran poorly, period (the entire trip, from car wash to my house, was about four miles in stop-and-go traffic with speeds up to 30 MPH). Conveniently the engine stalled just as I parked it in my driveway. Long story short–I had to get it towed and the mechanic had to replace both ignition coils. Was this just a matter of coincidence, or was there a possibility the car wash somehow affected my vehicle?

Thanks in advance for the help.

Sajeev answers:

This is pretty scary: it’s a conspiracy by the automakers to damage the sterling reputation the Camry’s durability! I’ve never heard of this problem with livery drivers (in regularly washed Panthers) so I suggest you find the nearest Mercury Grand Marquis for sale and BUY IT…SON!

I’m realizing that I need a Panther Super PAC: I’d make a difference in our society! Hey, if Colbert has one, why not the Crown Victoria?

But I digress. It’s unfortunate that water vapor does this, but it is true. One of the cars in the Mehta garage is a Mercedes buyback because of this exact problem. Or was. But that’s not the point: power washing is bad for electrics, but older motors with older rubber bits are susceptible to even a bit of vapor from regular car wash use.

Let’s make this simple: odds are your Camry needed a FULL tune up (plugs, spark plug wires, fuel filter etc.) anyway, and the magic powers of water vapor was the last straw.

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry.