ss turbo

!!!HELP!!! I have a 2008 Chevrolet HHR SS 2.0L Turbo that keeps overheating. When the car is cold the cooling fan cuts on when the switch is tuned on with ac on or off but when it reaches operating temp the fan will cut off and then starts overheating even with the ac on. It shows in some manuals a fan relay #50. On the LT models it has one of those but does not on an SS turbo model. Just has a 40amp fuse. The cooling fan does have a module mounted to the cooling fan frame which I have replaced through GM. I have also replaced the coolant sensor and still runs hot. I have checked the voltage from the computer to the coolant sensor and it is correct. I have not been able to find a switch or relay that activates the cooling fan when the ac is turned on. On certain models there is a sensor or switch in the back of the ac compressor but the 08 turbo model does not have that. For the lift of me I cannot fighre this thing out. Has anyone else had this problem or know what the problem is. Thanks

SS fan

Welcome to the site...You got me, when mine quit cooling I ran for the dealer, they replaced the fan....

ss turbo

Thanks, My fan is working fine when the car is cold. When it warms up to about 193-195 the fan will quit. I ran it up to 237 degrees and the fan still never kicked on. ????????????????????????????? I don't know. I have been working on this for 3 days and did everything I can think of including spraying all my electrical connectors with electrical spray cleaner and making sure all connections were tight. I also switched out another 40amp fuse. still nothing.

donbrew

A lot of people have found the manual to be wrong on the SS fan relay/fuse.

Did you open the pressure cap to make sure there is coolant in the hose? Could be an air bubble.

There is a lot of info on this site about the SS fan. I won't use the "S" word, but I don't care enough to search for the topic and provide a link (I have an LT).

ss turbo

I did think of an air lock or bubble in the system and there is coolant in the hose. It will circulate as the temp rises. At this point I am thinking that the computer is sending power (5 volts) or signal to the coolant sensor and the sensor is sending a temp reading back to the computer which suppose to send, if I understand it right, a signal to the cooling fan module which tells the fan to get it in gear or run. The part coming from the computer to the module and fan is where I scratch my head. Don't know how to check that.
The wires coming in from the computer to the module has a reading of around 12.5 volts with a small pin terminal off to the side of around 3.5 volts, going out of the module to the cooling fan I have a reading of around 3.5 volts. These readings are at room temp. I did check with a certified mechanic and he said that the voltage readings were correct. Any more suggestions on what might be the problem or how to fix?

I am getting ready to take it in to the GM dealership but was keeping my fingers crossed on maybe finding a fix from someone that has had the same problem or has seen this before.

Any and all suggestions are very much welcome.

Thanks again.

donbrew

Gotta remember all of those signals are "computer" signals, some are even TTL, some just hi-lo, some are not what you think they are (magic).

My veiled suggestion was to use the search tool, as many have had the same problem. I just don't have the time or interest to do the searching, but it is there for the asking.

ss turbo

Not real sure what you are saying but the only magic in this deal would be that I go out there, get in the car, and walla, everything works as it should. But I don't think that is going to happen. I got on this forum hoping to find out more information than what I have already found which has not been related to the problem I apparently have right now. I have read a lot of this forum and so far I have not found any that relates to what mine is doing. Not to say it's not there but I have not seen anything yet. Most of what I could find even close was a thermostat. That is not the case here. Thank you again for your response and thanks to this forum. It is the reason I have been able to check the things that I have. I am not very up at all on these late model vehicles but through this site I have learned a lot. Thanks to all.

firemangeorge

Fwiw. There have been a couple threads about cooling issues in regards to the SS. From the ones I recall reading about cooling fan motors not working correctly, it seemed to almost always end up being the fan motor itself and/or the module.
There doesn't seem to be any known specs to look up as far as the voltage checks you can do at the cooling fan module itself.
Well, I couldn't find any specs in the SS repair manual.

ss turbo

The cooling fan could be a problem I guess. It seems to work great when the car is cold but dies after reaching operating temp. (could be breaking down from the heat?) I did bypass the module to check the fan and it kicked right on and ran great. Once the car reaches operating temp you can't get the fan to turn on for nothing. I even tried turning on the ac and still nothing. I still wonder what is causing the fan not to run when the ac is on. From what I understand it should. Thank you Firemangeorge for your response and look forward to hearing other possible issues. Stay safe.

SS fan

Mine ran when it was cold also. I'm happy I gave up and replaced the fan, instead of replacing a motor,btw 237 was the magic # for me too !! my SS is still running strong at 85k. I should be thankful Vince gave me such a mild tune.........

Griot's Garage been treating me pretty good too...........