I Overheated My Car. What Now?

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Most RX-7 owners will never have to worry about an overheated car, but if you are one of the unlucky ones, the information on this page should be useful. By now, I'm sure you know that rotary engines don't take to overheating very well. Overheating usually results in warped housings, which results in the water o-rings not seating very well. This condition causes coolant to leak into the combustion chamber. Obviously, this is a bad thing.

If the car is overheating, the first thing to do is pull over. If you were running the car hard and idling would help reduce the temperature of the engine in a natural way, let it idle until the temperature gauge reads normal temp. If the car suddenly overheated due to lack of coolant or other reasons, shut off the engine immediately and allow the car to completely cool down.

With the car cooled down, it may be driven to a convenient place and examined for damage. If the car begins to run hot again, shut it down and have it towed.

Does the car still run? That is always a good sign. What you want to do is look for possible damage. Does the car belch out huge clouds of white smoke after it is started? This could be caused by coolant leaking into the chamber and being burned off by the running engine. It is rather normal for an engine to expel a could of steam when cold started or operated in cold weather, but excessive amounts of sweet smelling smoke almost certainly indicate burning coolant.

Does the car consume coolant, with no noticeable external leaks? If you continue to add coolant to the car with no external leaks seen on the engine, it may be being burned. The coolant may be leaking into the engine internally. This is what creates the cloud of white smoke. The best way to test for this condition is to look for bubbles in the coolant. With the car completely cold, remove the coolant filler cap. Now start the engine and look at the coolant through the filling hole. Do you see a steady stream of bubbles coming from somewhere in the engine? Now, rev the engine by grabbing the throttle lever at the front of the engine. Does the coolant bubble up and/or gush out? If these two conditions are present, it is a pretty good sign that the coolant O-rings are leaking and allowing coolant to enter the engine, and combustion gas to enter the coolant.

If you have performed the above test and suspect engine damage, it is best to have the cooling system pressure tested to be absolutely sure. Any damaged pressurized system will leak coolant into the engine, resulting in hard starting and cloud of white smoke. Most rad shops can provide this service.

Now, if the car shows no loss of coolant and still runs properly after being overheated, consider yourself lucky. Now would be a good time to figure out what caused the initial overheating and correct it so the situation does not re occur.

If you have suffered engine damage, the only cure is a full rebuild. The car may still be driveable, but the condition will continue to get worse until the car no longer runs. This may take days, weeks, months or even years. There are various temporary fixes that can be employed, but they are just delaying the inevitable. Better start saving for that new engine.

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