Loud Noise under car when it rains - Toyota Nation Forum : Toyota Car and Truck Forums

hkkc · 08-10-2011, 03:07 PM

my car is a bit older 1992 Camry but still runs well except for this issue.

It is a strange one, only when it rains, I get a loud noise, it feels like the muffler fell off, gets louder when you hit the gas. A LOUD rumbling and knocking under the seat, loud at 80+ kmph and above.

When it is dry and warm no noise. Been searching for an answer but only found others with the same problem.

Still cannot believe no one found the answer.

mazdaverx7 · 08-10-2011, 03:34 PM

check the catalytic converter heat shield and ensure its not loose. ensure all exhaust hangers are not crumbling form age. the rain can cause belt slippage but that wold cause a squealing noise over a loud exhaust noise.

hkkc · 08-10-2011, 08:40 PM

no, the shield is ok.. besides that would happen any day.. rain or shine.. this loud noise only happens when it rains?
There was a theory on a crack in the exhaust system and when water cools it, it opens up and hence the noise but cannot duplicate the scenario at the garage. I do think this theory holds some merit, but it maybe at the joints along the exhaust system, when hot it expands but when cool it contracts opening up the seals.
So maybe I ask the mechanic to tighten bolts along the eshaust system and see if that works.