Honda Car Forum

Greetings all. I've stumped my trusty Japanese mechanic with this particular issue, as it appears to happen only in inclement weather. Hopefully someone has experienced something similar or can give me a possible diagnosis.

I have a '94 5-speed Integra LS (Canadian) w/ 280,000/km's - I had the timing belt done @ 150,000/km's - and have had water pump, sparkplugs and wires, etc. All done and just had it tuned up a few weeks ago in hopes they would discover the cause of this issue.

Now for the mystery.

When driving in the rain for 10 mins+, which for Vancouver is quite often, thus giving the undercarriage plenty of time to get wet - a mysterious 'knocking'/flat-tire'esque sound will happen in 3rd + 4th gears...less noticeable in 5th. When I take the car out of gear, the noise goes away (at first i thought it was a shocks/CV boot issue). When I re-engage the noise will start again - it sounds like I'm running with a flat tire or that I just blew my exhaust off at the catalytic converter.

There is no temperature increase, no real loss of power in acceleration and the mystery is, when it's dry - there's no issue whatsoever.

Any ideas of where to start? someone suggested transmission bands?

thank you kindly for your insights gentleman (and women) of the forum.

so, after reading up in the forums on the heat-shield issues that are prevalent with these cars - I think that might be part of the equation.

could the heat shield issue be problematic enough to make that loud of a noise? from inside it sounds that the muffler has blown off.

thanks for your insights wise gentleman of the board.