I posted this on the 900 forum as well, but I figured I might get a response faster here, the car is a '93 940.


I got a call from the wife this morning.. "The temp gauge is all the way to the red" Did you shut the car off?? I asked, "Well no, I'm almost to where I'm going"

I thought that I taught her better than this, anyway, I had her pop the hood, check the expansion tank.... empty. She then described a device about .75" in diameter with two wires to it that was just "hanging there" near the radiator. After further interrogation, I determined it was the temp sensor in the radiator which is secured via a press fit into a rubber grommet in the radiator.

She then told me she left the car running yesterday for about 10 minutes in 85 degree heat. The drive home was only 5 minutes @ 30 mph after this. And she had only been driving 5 minutes after she called me this morning. So, hopefully the exposure wasnt too bad. Do you think I am screwed??? Was there maybe enough water in the engine to keep it somewhat cool?? This car has been fantastically reliable, and wouldnt you know it I just put on new rubber, exhaust, and Volvo rotors and pads all around.


Most importantly, what causued this sender to be forced out of the radiator?? Is this a common failure?? Shouldnt the expansion tank cap relieve excess pressure??

Help,

Matt



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'82 DL - 158k, '93 945 - 116k
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'82 DL - 158k, '93 945 - 116k

My wife did the same friggin' thing with my 740! I was suffering from a busted heater valve, but the result was the same. When she got home from a 20 minute, slow traffic drive with the car in this condition, you could hear it coming up the road. And, I have never seen an engine that hot! Even so, the engine seemed none the worse for the experience. I thought I would at least need a head gasket, but everything was fine once it cooled down and I replaced the heater valve. Unreal! That was over 50k ago, and we are still going strong! I hope your story ends as well, and it probably will . . . Allen

Thanks for the words of encouragement, last night I replaced the water pump, (which I planned to do before winter anyway), replaced the t-stat, and gave her a good flush, (the car), I then filled the system via the upper hose, and topped off the expansion tank. she runs fine now, held pressure overnight, no foam on dipstick, and no bubbles in the expansion tank. Crisis averted... hopefully. I might install the loss of coolant idiot light. I've seen some DIY instrucions floating aroud the site.

matt


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'82 DL - 158k, '93 945 - 116k

Here is the linl for the Plug+Cap..
http://www.fcpgroton.com/volvo240heatingcooling.htm
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john,, 1985, 245:Ti, 251k mi..so.california,,,1974, 145, 230k mi. ..

That happened to me too. Get a new Plug, and insert..also, as Greg says, new expansion cap + T stat as well..
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john,, 1985, 245:Ti, 251k mi..so.california,,,1974, 145, 230k mi. ..

Matt,

you gotta flog that woman! This is your VOLVO!! :)

I hope everything works out.

Mike

Pressure is relieved from the expansion tank cap. I think they often go bad. There are two caps I think, green and black. I "think" the pressures are different but individuals suggest to replace with the black one. Cheap at fcpgroton.
I replaced all of mine with black (3 cars) for preventative purposes.

Not sure what else can cause excess coolant pressure. Don't overfill.

Might as well replace t-stat and do a good flush in case the t-stat got stuck and caused too much heat...

Greg