1999 sunfire GT 2.4L 215,000km

[Jeremy_steven10]

Ok, highway driving, temperature rises to 222 degrees, no engine fan. I changed thermostat, coolant, checked power to coolant temp sensor (5 volts), getting power to fan (checked), fan works but when on highway cruising, fan doesn't want to work. Cold coolant level is proper. Also changed coolant temp sensor with a used one wrecker. Maybe try new brand new sensor next. But ohms on sensor seems to be ok. Temp reading is there. Fan doesn't kick on with a/c either. I have to crank heat to keep highway driving safe temp wise. Also disconnect coolant temp sensor to run fan constant. So I read I guy reset PCM by disconnecting battery and changed coolant temp sensor and that worked for him, so I'll try that now. And also had shop check cooling system pressure, they said was fine.

 

[EaOutlaw]

This is the 3rd thread you started with this cooling fan, several people have tried to help, yet many questions that we asked of you went unanswered.

I am not sure we can help you like this.

Perhaps it is time to have the car repaired by a qualified technician, before you burn up the engine or blow the head gasket.

 

[melsg5]

I agree, in your previous thread you stated you had a bad connection and it started coming on at 152 then a few posts down all of a sudden it doesnt work and you never responded when asked if you went back and checked the connection. You had it in a shop why didnt you let them scan it to see if the PCM is commanding the fan to come on? You were also asked if you AC compressor engages and never responded, if the compressor doesnt engage the fan wont come on with the AC.

 

[Jeremy_steven10]

Yeah well thanks, and fan doesn't come on with A/c. temp is at 222 degrees steady on highway. And runs ok around half way mark in town. So my friend says flush the heater core, and cut the thermostat in the mean time. Fan works fine while idle, and around town, but highway doesn't respond. Appoligies for so many threads. I'll bite the bullet and bring to the stealership perhaps. Thanks for your input, as it is greatly appreciated.

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[melsg5]

I understand the fan doesnt come on with the AC but you still havent answered whether the AC compressor comes on?
So now we are back to the fan does work and you are only guessing about whether it stops at highway speeds based purely on the increased engine temperature. The fan is for cooling the engine at low speeds when there is no forward motion of the car to force air through the radiator. Is there anything blocking the radiator?
Have you ever flushed the cooling system, not just the heater core?
Do you have a check engine light on?

 

[Jeremy_steven10]

No sorry, no check engine light, and I just did a 3 day flush coolant flush (prestone)... There's no open vents in the front, so may not be getting proper wind Channel, just at dealership now, see what they have to say.

 

[Jeremy_steven10]

Ok not sure how to delete all my treads. Admin can delete perhaps, and as for my overheating problem, blowing white smoke, mechanic buddy said head gasket blown. Bought NnW nanotechnology bottle, dumped half in my cooling system, and presto! No more over heating. But I used only distilled water with KnW solution and been driving for 350 miles so far, recommend 500 miles before dumping and switching to 50/50 coolant again. Before so, I used brake clean on radiator and cleaned with hose water after wards. Also took E3 spark plugs out and put good old NGK iridiums back in. Also changed out engine coolant temperature sensor again. Whatever it was, not over heating at the moment, been a few days now. I'd like to thank you EaOutlaw and melsg5 for all your help. I appreciate it, and tip my hat to you 2.

 

[EaOutlaw]

OK so your problem was a blown head gasket. I highly suggest you take the time and money to repair your car properly.

I have been working on cars since 1985 and I can honestly tell you there is not one Mechanic in a bottle product I would recommend to repair a head gasket.

All these chemicals do is waste your time, money and cause more damage to your cooling system and engine.

If you do not believe me pull a compression check for yourself, I will eat my words if you find compression on all your cylinders is within factory specifications.

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[Jeremy_steven10]

Yes sir, $25 for new head gasket. Gonna find someone who can do it now. Cause for head gasket to fail, is wiring. When I wiggle my wires, close to ect sensor, fan kicks on and off. So gonna have the connector replaced and soldiered on and Shrink wrapped. I have a guy who can do the head gasket, he'll hate me for it. Lol. He's a truck guy. Thanks again for all your help everyone. This is the best of not only Pontic sunfire forum I could find. Not to mention, very helpful and responsive. Detailed as well.