1990 Civic Sedan 5 speed 96K miles

Car overheats and is losing coolant but I cannot find out where. The higher the RPM the hotter she runs. The fans are cutting on and at idle the car runs a fine temp unless boiling over.

Does this make any sense?

 

If you cant find a place where its leaking from maybe its coming out your exhaust. THat would be due to a broken ghasket.

 

That is a limited explanation. Which gasket are you talking about? Why would this mean the car is raising and lowering engine temp with the RPM?

 

I think he means head gasket.

Maybe your Water Pump is shot and that's where it may be leaking from.

 

I am not getting any funky oil though, I was thinking water pump as well. Is there an easy way to tell one way or the other?

 

Easy way to see if your water pump is working....

Take the cap off the radiator.

Start the car and let it warm up.

When the thermostat opens your anti-freeze should be flowing like a river if your water pump is working properly.

If it isn't moving(or hardly moving)when your car is at normal operating temperature then I'd guess it was the water pump.

 

head gasket

 

water pump.

 

Given the mileage this car, changing the headgasket. waterpump, and replacing the hoses would not be a bad ideal.

 

U can have coolant enter the combustion chamber but not the oiling system. Usually from a crack. Have you even done a compression and leakdown test? That will tell you a lot more.

Janos

 

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Theres not many other ghaskets that let coolant our your exhaust pipe lol. It wouldnt explain the heat fluctuation, but explains the loss of coolant. Low coolant plus high revs could easily mean that theres not enough coolant to cope with the large amounts of heat from an engine when its working hard. As your revs drop the coolant is able to get it back to a reasonable temp again.