wildazme

well on my way to and from work my car has started overheating. My coolant is full, my hoses are fine, but im not sure if my fans are working correctly. when i turn my a/c on the fans come on but when i pulled over when the car started to overheat and had my heat on full blast the fans werent on at all. any ideas what could be causing this?

socalwrench

Well, obviously the fans need to on to move air through the radiator when parked or at low speeds, so I would start with that. I don't have a schematic in front of me, but I believe the fans are controlled, indirectly, via the coolant temp. sensor. I would need the schematic to pinpoint a possible relay that's not actuating also.

Let me look for it.

socalwrench

Well, there's definitely a pcm controlled relay for the fan. And, there's also a temp. sensor sending info. to the pcm.

For starters, find out if there's 12v to the fan and back to the relay and then the PCM (if needed), and verify that the temp. sensor is working (a quick resistance check would work, but I don't know what the normal ranges are).

Also, make sure the fan itself works. Grab a few test leads or extra pieces of wire and throw 12v 6a at it- a trickle charger works great for this.

wildazme

If i new what any of that stuff was i would be good.lol thanks though

Nuke

My ex-wife had no idea what made the car work either. I suppose "Turn key, push pedals" works for some people.

wildazme

had it at the shop today, the fans arent the problem they work , relays were checked mechanic said they were good. he gave me some story that the temps had to be set to the stock temperatures for the car in my tune and after playing with my relays but reusing the same ones and changing the tune the car seems to not overheat anymore. i have no idea what was wrong.

wildazme

well it happened again. back to the drawing board. ? if i rig the fans to run whenever the car is on , is there any downside?

Simon1

When you say "overheat" what do you mean? Does the car go into failsafe? Are there any codes? Is there coolant leaking? Give some better decriptions of when/where /how.

Complete list of mods. Including PSI.

Last thing that was serviced/modified on the car.

I know those questions above seem stupid but, sometimes our cars think they are overheating when they are not. I had a sensor wire get pinched for the cylinder head temperature sensor. The car beleived the heat was spiking to well over 200 degrees when it was still warming up in the morning. A replaced wire and everything was fine.

wildazme

ok when i say overheating, i mean im driving the car for awhile and the temperature needle climes all the way to the red danger mark on the gauge. I put the heat on full blast to get it to fall slightly under the red mark until i can get the car off the road. when i open the hood the fans are not on. there is no coolant leaking, my hoses are fine. The list of mods are in my signature and i have been driving with those mods a few months and everything was fine. the last thing i had done on the car was an oil change. also when the car gets that hot my overflow tank fills completely up.

157dB

Dont you mean, turn key push pedals cuss call wrecker have towed to
stealership pay money turn key push pedals pay money more cussin.
Come on this guy thinks there are TWO fans (plural). Lost.
You cant lead the blind over the internet.
Two words.
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