Drove 2005 Mazda 6 with 6 cyl through water maybe 10" deep. A shuddering noise started almost immediately after, and car overheated, though I made it home.

When I start the car now, it overheats very quickly. The shuddering noise comes and goes. The shuddering does not appear to be the engine, as it runs as smooth as ever, and revs cleanly evenwhile the shuddering occurs.

Additional symptom is a slight, inconsistentloss of power steering while this shuddering occurs.

A red warning light on the dash is now always on (a red light with a silhoullette of a key).

Any thoughts onwhat might have happened?

 

Is your fan kicking on? Could have possibly shorted out the circuit. If that fan doesn't run, you'd overheat real quick.

 

Could have taken out a lot of electrical systems by driving through water. But you may have water in the engine still which will cause the shuddering. Sudden temperature changes could can cause cracks in the block. But I doubt this is the problem here.

The act of driving the car could evaporate the water and it will recover. But I would be cautious as this could break something else.

I'd start by checking all the fluids and see if anything has water in it. A foot of water is not a big deal as this would probably not even breach the oil pan. But I would make sure that you are holding your coolant as well.

I'd get under the car and check the electrical systems that touched the water. Clean the connectors, apply dielectric grease to keep out any more moister.

 

Thanks for the responses... I've just replaced my computer so I've not been able to access this site. Dang hurricane.

I'll check the fan, and look around a bit more underneath tomorrow...

A guy at Autozone suggested a pulley might benot be spinning freely,though doesn't the water pump sit up pretty high and run off the timing chain? A sticking pulley sounds like it might cause that shuddering noise. Does that sound reasonable?

 

Quick update... looked again at the radiator fan. One of the blades is broken off! The shuddering is due to the off balance fan spinning. When the fan spins, the shuddering starts. When the fan stops, so does the shuddering. Never would have guessed a missing fan blade would have made such an impact.

I appear to have multiple symptoms, as now (after drying out for several days), one of the pulleys is squeaking irrattically.

I also noticed that when I turn the key to on, but don't start the car, the "thingy" (is it an air flow sensor?) at the intake side of the hose that carries air from the air filter is making an odd buzzing noise. It sounds like a combination of a weak car door chime and a computer accessing a hard drive.

2 questions? If I replace the radiator fan, and the car is driveable, will the squeaking pulley cause any harm? Also, does this thingy normally make any noise? I don't recall ever hearing anything from it.