Hi, I have a 1992 Honda Civic EX 4 door 5 speed. I've had a running hot condition recently (not quite overheating, but close). I took it to a shop on Friday and they tell me it's a blown head gasket. They also told me that the radiator was very low on coolant and has a leak. I took it in because the radiator fan was not coming on ever, so I had to drive with the heat on all the time to keep it from overheating. I see no antifreeze in the oil and I see no white smoke in the exhaust. The shop did not use an exhaust gas analyzer over the open radiator cap, but told me it just kept bubbling after the thermostat opened up. What should I do next to determine if the head gasket is shot? Does this even sound like a blown head gasket? Thanks for your help.

 

My opinion is that you first fix the fan problem (does jumping the coolant temperature switch on the thermostat housing cause the fan to run?) and the radiator leak. Then go from there.

 

Go to an auto part store, get some "stop leak" and fill it up with your coolant. It should stop your coolant leak. See what happens if it still leaks, if it does you might need more things. Check this out before doing anything else.

 

What's the procedure for jumping the coolant temp switch?

Is it a good idea to replace the cooling fan relay due to age? My AC compressor fan will not turn on either (but compressor switchs on) so I'm thinking of replacing the relay on that, as well. Both relays are original and the car has almost 250k miles on it.

 

First check whether fuses 13, 33, or 35 is blown.

Engine OFF: Disconnect the connector for the 2-wire (2P) coolant temperature switch located in the thermostat housing. Get a ~4-inch piece of wire with a section of insulation removed at each end. Insert each end of the bare wire into separate terminals of the free connector (leading to the fan relay). In essence, you are completing the circuit at the free connector.

Turn the engine ON: If the radiator fan now runs, then the temperature switch is bad. Replace it. If the radiator fan does not run, then the radiator fan or fan relay may be bad. Next, supply power directly from the battery to the radiator fan. If it runs, the radiator fan relay in under-hood fuse/relay box may be bad or there is a circuit/wire problem.


I don't think you need to replace good relays. As mentioned above, run power directly to the condenser fan to test whether it works.