1991 Honda Civic Cooling fan Running after a therostat change

Scotty

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#1
My 1991 Honda Civic DX Hatchback with a 1.5L D15B2 engine, auto trans with 157,000 miles had the water pump replaced and therostat replace due to the therostat not opening, and breaking a bearing in the water pump. I didnt blow the engine on the highway going 75 MPH or the timing belt didnt break either. The water pump i had in there was replaced with the timing belt at 142,000 miles. I only got 14,000 miles on out of the water pump. Now im on my second water pump due to the therostat going bad. Heres my problem. I replaced the therostat since the orignal one was shot. When i went to autozone, they didnt have the stock 180 degree therostat for the car which it is called for in my repair manual for the car. They gave me a therostat for a 195 degree rating that opens at that temperature. Now, my cooling fan runs all the time after the engine gets to that 195 degrees. It never ran before at all with the orignal therostat. Is there a way to adjust the fan so it wont come on at that temp, or i just deal with it?? Also, i have no codes in the computer or my check engine light isnt on at all! My temp gauge is about under the middle range in the normal range like it has been in since i owned this car. Otherwise, it runs like a top. thanks, Scotty
 

ironhead

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#2
First off, I don`t know how a bad t-stat can ruin the bearing in the waterpump. It sounds to me like someone is trying to pass the blame off of a poor quality rebuilt part. I will never again use a rebuilt water pump, just way too many comebacks. New ones aren`t usually very much more money.
Second, if the factory thermostat for that car is 180 degrees, that`s the only thing you want to put in there. Running a higher temp `stat can cause all kinds of confusion in the PCM. That is why your cooling fan is on. The PCM thinks that anything over the normal temp (180) is overheating so it is trying to protect the engine by cooling it down. It may also be richening the mixture and retarding the timing to bring the temp back down. This will decrease your performance and fuel economy. Also, some models of Hondas in the early-mid 90s have aluminum cylinder bores, no sleeves, no plating. ANY overheating, no matter how slight, can cause serious engine damage. That is why the engineers put the lower temp `stat in there in the first place.
Good Luck,
Guy
 

Paul

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#3
The Honda thermostat is only $17,its part number 19301P08316.The Cooling fan should begin to operate when coolant temperature reaches approximately 191-197°F,and fan should stop running when coolant temperature drops to approximately 182-188°F.So with a 195 deg t stat,Its little wonder the fan stays on.Stick with the Honda parts and you shouldnt have any troubles.
 

Scotty

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#5
I figured that the therostat was the cause of the fan being on. When i get back from Vacation, i will change it to the 180 degree therostat. Thanks for the help, Scotty
 

Scotty

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#6
I went to the car this morning, removed the 195 degree therostat, and replaced it with the proper therostat. the fan is staying off like it should. the problem is now fixed and it is running better, and i hope my gas mileage gets back to where it was before i put in the 195 degree t-stat. thanks for ur help on this. Scotty
 

Scotty

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#8
Ironhead, i was getting 42 MPG before the whole mess began. My friend is using the car since i will be on vacation for the next 10 days in freezing Connecticut. I'll call her over my vacation in a few days to see if the gas mileage comes back to where it was. I did notice the exhaust was alittle rich when the 195 degree t-stat was in there. She told me it was running funny and eatting alot of gas. Its good now. Just got to check the water for a few days until all the air is out, but i got all of it out. I'll post back sometime next week on the progress of the mileage, Scotty
 

Scotty

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#10
I did talk to my friend that is borrowing the car, and the gas mileage is back to normal. She told me that its driving good, and getting about 200 miles on a 1/2 tank of gas. no other problems. its a done deal. thanks for all the help. Scotty