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View Full Version : '90 legacy running hot.



snake
09-13-2009, 05:22 PM
I've got a '90 legacy with 250K on the clock. It seems to cool OK idling but runs hot running down the road. Already had a thermostat swap, and one cooling fan isn't working. I know the fan should not have much to do with the driving /cooling part, but I still need to repair what we know is bad first. It is the passenger side fan, is that the condenser fan or the radiator fan as I cannot find any info on this. It isn't leaking oil in the water, or water in the oil, no known leaks but I'm starting to suspect a head gasket. Haven't tried the rad cap yet either, so maybe I should do that first? Also, where can you buy a fan? I found several on car-part.com (junkyard) but thats it so far...

Thanks in advance...

dieselrab
09-13-2009, 05:36 PM
Well I don't think that it would be a radiator cap, normally it would still probably over heat at idle too, but that's not to say I would rule it out though either. Does your A/C work? Because if it works and you use it it should kick the A/C fan on then you would know which is which. You can unplug the connector on each fan and run jumper wires straight to your battery to see if they kick on. If you unplug ther connector and you have it facing you with the clip part pointing towards the sky the negative is the left terminal and the other two are positive(either one will work they are just two different speed settings just put it in on to see if the fan turns on). If it works then check fuses relays and wiring. I would think about changing the water pump, kind of sounds like it can't make enough flow in the systen to cool it while your driving it.

Scorpion8
09-13-2009, 10:45 PM
I would think about changing the water pump, kind of sounds like it can't make enough flow in the systen to cool it while your driving it.

Could be that. Is this a new or recent occurrence or has this always been happening with this car? When was the last time you had a radiator flush? Also, check to see if the coolant temperature switch is turning on the fan when it sould. You can try turning on the a/c which forces the sub-fan (2nd smaller fan) to come on and see if that cools it down. I don't recall if these vehicles also have a bottom plate piece below the radiator which forces airflow THRU the radiator instead of allowing it to go around, which would suggest only a problem while driving, not while idling. Some people on some cars remove that thinking it's extra junk and it's really there for a purpose.

snake
09-14-2009, 09:54 AM
Thanks for the advice so far... Not really sure about how long it has been doing it, it is a customers car- I do repair on the side so not a professional but lots of experience... The A/C doesn't work and I haven't looked into why it doesn't as he doesn't seem to care for some reason. I ran 12 V to the bad fan and it didn't turn, ohm'ed it and didn't show good, then plugged it into the other (driver's side) connector (they are the same believe it or not) and it didn't turn there either. Will that fan only turn when the A/C is on? Since the condensor is as long as the radiator, I assumed both would turn during hot idle and/or A/C. If I replace that fan on the passenger side and the A/C doesn't work, does that mean that side will never be needed anyway? The pass side had 12V going to the connector when I checked it so I assume it was supposed to be running... Also, the thermostat and waterpump were both swapped before I got the car with no improvement. Not sure if the rad has ever been flushed either, but normally a clogging rad will just run a bit hotter every year until it needs to be done. The customer stated that this thing runs right and all of a sudden it starts heating up like there is a restriction (lower hose collapsing maybe?)

dieselrab
09-14-2009, 10:06 PM
Well as far as I'm aware the smaller (sub fan as stated by scorpion8) on the passenger side will work when then A/C is on or when the engine is extreamly hot. If the fans dont opperate when connected directly to the battery they are junk. You can try to get the A/C to kick in by jumping the low side pressure sensor, located on the reciever drier on the passenger side by firewall. with a paper clip on what ever you have available. I know that there's four terminals not sure exactly jumping which two turns on the compressor I know one will turn on one fan one will turn on the other fan and one will jump the compressor (I know this for sure because I did this with my '93. A collapsing radiator hose could also cause this overheating problem.

Scorpion8
09-16-2009, 12:23 AM
Well as far as I'm aware the smaller (sub fan as stated by scorpion8) on the passenger side will work when then A/C is on or when the engine is extreamly hot. If the fans dont opperate when connected directly to the battery they are junk. .....

^^^ What he said. :)

brandonmillsap
08-12-2011, 12:24 AM
I have learned a great deal about ac condenser (http://www.car-stuff.com/accondenser.htm) concerns. Sorry to have revived this thread, but I just want to acknowledge the thread maker. Thanks for sharing the info.

91 Legacy Wagon
08-25-2011, 04:26 PM
Well in my 91 Legacy wagon i took my radiator out, and in front of it under neath my front gaurd and grill is the ac condernser. And for some reason which is probably good, my fans do not turn on unless my engine is hot.