850 running hot

red850 · Post by **red850** » 03 Jun 2011, 15:45

Hello Everyone,
I know i haven't been contributing alot lately but i really need help. MY 1996 volvo 850 turbo is runnning hot. I changed the relay, the cooling sensor, and the fan. It still seems to be running hot. I ride around the block to see if i can make the fan turn on but it does not. Any suggestions will be deeply appreciated. I CHANGED MY WHOLE ENGINE SO I WOULD BE WILLING TO DONATE ENGINE PARTS IF SOMEONE GIVES ME THE RIGHT ANSWER.

Post by **Ozark Lee** » 03 Jun 2011, 16:11

Change the thermostat and the ECT sensor. By "hot" how hot are you talking about? Where does the gauge read?

...Lee

se13allmylife · Post by **se13allmylife** » 03 Jun 2011, 16:18

This could be a really dumb suggestion but could your thermostat not be fully opening or gummed up . In all honesty I've never played with the fan on my 850 so i'm not totally sure of the setup but I know once on my VW Santana the thermostat jammed virtually shut and the fan would'nt cut in , I had to bridge it , once I'd changed the stat everything was back to normal .

Swedish Chef · Post by **Swedish Chef** » 03 Jun 2011, 17:01

My 850 N/A fan almost never comes on unless its extremely hot out or i have the A/c on, however yours should be if its overheating, try running the engine to normal operating temp then carefully feel the upper rad hose temp (this takes some well thought judgement) if it feels hot the thermostat is operating however it may be only partially opening, obviously if its cool the thermostat is stuck closed and or you have a plugged rad. You say you changed the engine is it rebuilt or used? did you already install a new thermostat /pump. Ive also seen broken pump impellers before, does the motor suck in coolant from the overflow? If not that is also another tell tale sign of thermostat or pump failure!
Hope that helps.

red850 · Post by **red850** » 04 Jun 2011, 00:24

Thanks everyone, yes it is a new used engine but i changed the water pump. I have no leaks and it runs fine for about 20 miles. I had to empty the a/c lines before I took out the old engine out so even when I put the a/c on the fan still won't go on. I am going to try running it again tomorrow. I also changed the thermostat.

red850 · Post by **red850** » 04 Jun 2011, 02:05

Oh and by the way when I say cooling sensor I mean the sensor right under the thermostat cover. Is that the ECT sensor? I should say that when the temp does climb it got to about the bottom of the red mark, then I just pull over and let it cool. I also have to say that when it rose to that red mark that was the day before I got the cooling sensor. The other thing I did yesterday is I drove with the heat on which I think help keep the temp nice and level.

Post by **Juan62** » 04 Jun 2011, 03:21

If you have no clogged radiator; drain, flush, and refill with Volvo Coolant Only. ( I chose NOT to add distill water). Make sure you use a Wahler thermostat...Volvo's are picky with other brands. And if you do decide to mix water, make sure it is distil. Wal-mart sells them for under $1.00/gal. Let us know when you fixed it.

Post by **Ozark Lee** » 04 Jun 2011, 05:15

red850 wrote:Oh and by the way when I say cooling sensor I mean the sensor right under the thermostat cover. Is that the ECT sensor? I should say that when the temp does climb it got to about the bottom of the red mark, then I just pull over and let it cool. I also have to say that when it rose to that red mark that was the day before I got the cooling sensor. The other thing I did yesterday is I drove with the heat on which I think help keep the temp nice and level.

It sounds like you are on top of it now. Check that your engine cooling fan is operational by grounding, one at a time, the Yellow wire and the Yellow/White wires that go to the center of the fan relay. One should give you low speed and the other high speed on the fan.

...Lee

Swedish Chef · Post by **Swedish Chef** » 04 Jun 2011, 09:51

If the heater is helping to keep it stable then it definately sounds like your fan isnt working (like you didnt already know this)
It sounds like Ozark Lee has the right place to start, Could it be a faulty relay? electrical isnt my Forte so i'll just say Good luck with it, there is also wireing diagrams under the repair database in case you wer'ent aware!

red850 · Post by **red850** » 04 Jun 2011, 12:50

Thanks Chef, yes I think my problem is the fan, but I got a new one from fcp. I also got a new relay from fcp. I am in the same boat, not good with electrical. I wonder if I accidently damaged a wire when i removed the old engine.