91 Civic Hatch Thermostat Replace?

1991CivicEf9

Cruiser
I have a bad thermostat in my 91 civic hatch. Stock motor. Is there anything else I should replace while doing the thermostat? My buddy told me to replace the Thermostat switch aswell but i'm not sure. Also, how would I go about replacing the thermostat? Remove the top rad hose that goes to the engine and go from there?
 

Kensai

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If you ran low on coolant its probably a good idea to replace the coolant temp. sensor.

Check the hoses while you're at it as well!
 


Blood_Shot

Banned
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how do you know its bad

when was the last time you had that fluid changed?

things to think about
 

jlicrx

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Registered VIP
5+ Year Member
I have a bad thermostat in my 91 civic hatch. Stock motor. Is there anything else I should replace while doing the thermostat? My buddy told me to replace the Thermostat switch aswell but i'm not sure. Also, how would I go about replacing the thermostat? Remove the top rad hose that goes to the engine and go from there?
first off, you should get a service manual for your car and not listen to your buddies - the manual will tell you everything you need to know in making repairs

second, your buddy is most likely referring to the switch that is on the thermostat housing on 92 and up cars, but it is not located there on a 91 - that switch is the cooling fan switch - on the 91, the cooling fan switch is on the back of the block next to the oil filter - if your cooling fan is working, the switch is o.k

third, the thermostat is not located where the top radiator hose goes into the engine - it is located where the bottom radiator hose goes into the engine, which is just behind and below the distributor - this is the instructions from the 91 factory service manual for replacing the thermostat

 


1991CivicEf9

Cruiser
Well for one, When I run my car till it gets hot (a few miles or so) and turn it off, it won't start back up. It just cranks but does not turn over and actually start. I replaced the ECT sensor, so it was not that. So I turned the car off when it was hot, took the rad cap off, and tried to start it again. It shoots fluid like a fountain, so basically the thermostat isn't opening up to let it go thru the engine.
 

jlicrx

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5+ Year Member
not starting when the engine is hot can sometimes be a faulty igniter in the distributor - do you have any codes showing on the ECU? - a faulty igniter would be code 15, meaning the red LED on top of the ECU will be flashing 15 times
 

1991CivicEf9

Cruiser
not starting when the engine is hot can sometimes be a faulty igniter in the distributor - do you have any codes showing on the ECU? - a faulty igniter would be code 15, meaning the red LED on top of the ECU will be flashing 15 times
Wouldn't that throw a CEL?
 


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