Aux temp sensor

ReVolvoLution · Post by **ReVolvoLution** » Mon Apr 24, 2006 2:19 pm

Well... after replacing the usual coolant temp sensor in the top of the block without success i'm looking for a cure to my COLD coolant read out.

Where the hells the Auxillary Coolant Temp Sensor located???? The Haynes book of lies says its on the Turbo coolant return hose but i'll be fudged if i can see it

Found the Aux Water Pump but cant even see anything there either!!!!

Could i be barking up the wrong tree here tho... anyone had to replace the Aux temp sensor too?

Cheers in advance if anyone can help with this one!

chris1roll · Post by **chris1roll** » Mon Apr 24, 2006 5:02 pm

On aturbo, the one for th einfo centre is Under the thermostat. It is most likely the wire wil have been pulled off and be floating about under all the pipes somewhere.

ReVolvoLution · Post by **ReVolvoLution** » Mon Apr 24, 2006 8:18 pm

cheers chris i'll check that out tomorrow mate!

Already replaced the usual one that causes this problem but i'm still reading cold

The car still runs fine but sometimes takes a couple of revolutions before she splutters in to life!!!

martinholmesuk · Post by **martinholmesuk** » Mon Apr 24, 2006 10:11 pm

Engine temp sensor.

look at inlet manifold (big black or silver top part) at back where the 4 pipe parts go there is a sensor held in by one of the bolts which keep the inlet manifold on.

That's the one which telling the info center how hot the engine is.

it's a black sensor with a silver part and does not screw into the engine and is held there.

chris1roll · Post by **chris1roll** » Tue Apr 25, 2006 6:51 pm

martinholmesuk wrote:Engine temp sensor.

look at inlet manifold (big black or silver top part) at back where the 4 pipe parts go there is a sensor held in by one of the bolts which keep the inlet manifold on.

That's the one which telling the info center how hot the engine is.

it's a black sensor with a silver part and does not screw into the engine and is held there.

Thats not for the info centre, thats for the auxillary water pump temp switch, Its just a switch, like the one in the radiator, either on or off. I Expect if you hokoed the info centre up to that it would probably tell you it was cold before jumping to STOP (or maybe the other way around)
There is a second one for the aux pump on earlier turbo's, it is positioned in the water coolant line from the turbo, and the two of them are wired in parallel, so that if either of them comes on, the pump will operate (with the ignition off, theres no need of it when the engine is running as the turbo is sufficiently cooled by the oil and the engine water pump.
I know this because I had to create all the wiring for it..twice.

martinholmesuk · Post by **martinholmesuk** » Tue Apr 25, 2006 11:13 pm

Ok thanks, learn something everyday.

ReVolvoLution · Post by **ReVolvoLution** » Wed Apr 26, 2006 1:55 pm

Cheers Fellas!

Unfortunately the problem is still there tho!

Mart - That was the one I was looking for mate but if what chris says is true its pointless checking it now

I had thought it was feeding the info back to the info centre through the Aux temp sensor but it looks like i was wrong too!!

I've checked below the thermostat chris and can see quite a chunky cable (unlike the thin one for temp sensor above thermostat) going on to something but its quite firmly sat in there and with limited room couldnt pull it off

Tested the theromstat while i had a check this afternoon and the top hose for the Rad gets hot relativly quickly so its circulating and doing its job, when the ignitions turned off the Aux pump comes on for about 25 seconds as its supposed to but i'm still reading cold all the time

Checked all the wires from under the hood to the harness and there all connected ok by the looks of things. Could it have un-plugged itself at the back of the dash?? Or at the ecu maybe??