Jamoolian
05-18-2008, 10:22 AM
Guys, this is my first rotary engine car. It's an 04 with approx 86K miles. A few thousand miles again, I began experiencing a scary event, and my mechanic can't seem to figure it out yet (no "bad readings" on the diagnostic computer) so I'm hoping somebody can help us. Here's the symptoms ...
When I've been driving on the highway for an hour or more with the a/c on, up and down long hills, maybe 75-80 mph, a very bad noise develops in the lower engine. If the car had pistons, I'd say it sounded like it needed a valve job. Sounds like valve clatter. Oh, and at the same time, the radiator light goes on. If I shift to a lower gear and turn off the air, the noise dissipates, and if I get off the road and let it cool for a bit, it goes away until the next occurrence under similar circumstances.
The noise does not occur during every day home to office driving, only longer trips where the engine is stressed.
As I said above, the diagnostics don't indicate any major failure. It's like the computer is occasionally "tricking" the engine into feeding it less coolant than is needed. My mechanic, a guy I trust, says the coolant sensor could be bad, but would that result in this serious engine knock? He also thinks it may be the result of a malfunctioning catalytic converter.
Any ideas or similar experiences and fixes would be greatly appreciated!
Thanks,
John A.
When I've been driving on the highway for an hour or more with the a/c on, up and down long hills, maybe 75-80 mph, a very bad noise develops in the lower engine. If the car had pistons, I'd say it sounded like it needed a valve job. Sounds like valve clatter. Oh, and at the same time, the radiator light goes on. If I shift to a lower gear and turn off the air, the noise dissipates, and if I get off the road and let it cool for a bit, it goes away until the next occurrence under similar circumstances.
The noise does not occur during every day home to office driving, only longer trips where the engine is stressed.
As I said above, the diagnostics don't indicate any major failure. It's like the computer is occasionally "tricking" the engine into feeding it less coolant than is needed. My mechanic, a guy I trust, says the coolant sensor could be bad, but would that result in this serious engine knock? He also thinks it may be the result of a malfunctioning catalytic converter.
Any ideas or similar experiences and fixes would be greatly appreciated!
Thanks,
John A.