Piston Slap: The German TL's Audi 5000 Syndrome?

Mark writes:

Hi Sajeev,

I have a 2003 Acura TL-S with 106K miles. I bought the car in 2013 with 84K and it was/is in excellent shape. I checked and made sure the car had the transmission recalls performed (I know there were a lot of issues with Honda/Acura 5 speed autos) Back in July I noticed on a hot and humid day it was difficult to move the gear selector from P to Drive. It seemed stiff but there were no other indicators of transmission issues.

I went to every Acura forum I could find and most issues were related to actual transmission problems and failures. There were some suggestions that the brake light switch might be failing. I replaced that (even though the brake lights work fine) no luck. It then started giving me fits about coming out of Park. I would have to use the key to move it into Drive or Neutral. Then it stopped doing that for a few months. Now it occasionally will not go into Reverse from Drive unless I shift down to then back up. The action is still very stiff but it will go into gear. Once you are going the Transmission is fine, it shifts perfectly, there is no missed shifts, clunking or any of the usual signs of an imminent transmission failure.

I live in Germany where Acura does not exist. The local Honda dealers are clueless since they have very little experience with Automatic Transmissions. Local mechanics are the same, very little experience working on automatic transmissions. I can’t find any useful information online or any examples of this issue. Perhaps you can help?

Thanks,

Sajeev answers:

Stuttgart is pretty far away from Ingolstat, and yet your German Acura’s infected with Audi 5000 syndrome?

Such an intermittent problem suggests a mechanical bind inside the shift mechanism, or perhaps electronic fault (just not the brake light). There’s also ammunition against Honda’s neutral safety switch, or Transmission Range Switch. The TRS can indeed interfere with the “interlock” system.

Unless you regularly spill large amounts of milky, sweet/sticky flavored coffee on your console to really screw it up, I suspect the TRS (or its wiring harness?) is at fault. To wit, this YouTube video:

What say you, Best and Brightest?

[Image: Acura]

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.