Again, coolant temp sensor?

[scotty73]

Back a few months ago when i was off on hols on a hot day i got the STOP warning light with beeps and engine temp warning, i posted on here about it and was told by Jasper5 i think it was to change the temp sensor.
Done that and all was fine until a week last Friday towing the caravan on the M5 in traffic... Once the traffic had calmed a bit with heaters on full blast it stopped and was fine until today.

Then towing up a long old stretch of an hill (the black rock to other Welshies) it happened again until i could coast down a hill.

Are these things prone to crap out often or have i bought a dodgy sensor?

[DaiRees]

Are these things prone to crap out often or have i bought a dodgy sensor?

Or is it actually overheating?

[grasmere59]

I'd say it was overheating as i'd never seen my temp gauge rise from 90 deg untill i had the van on the back last week and it headed to the red on more than one occasion,i think as the oil temp increases the water/oil cooler at the oil filter reverses it actions as i can't see how when the oil temp is hovering at 130 deg+ the coolant temp can possibly stay below 100 deg or am i wrong?

[Welly]

Have you seen this 'ere fred.........viewtopic.php?t=1452&start=0#p13555

[scotty73]

Are these things prone to crap out often or have i bought a dodgy sensor?

Or is it actually overheating?

Quite possible, i'd say my temp never went over 95 degrees i'll have to show my mate the thread Welly pointed me too and see if theres anything he can do.. cheers for that Welly.

[Welly]

It's well worth dropping the coolant and fitting a new thermostat on the HDi. Was one of the first things I did on mine.

[Doggy]

Please correcct me if I'm wrong, (again! ), but IIRC, don't D8 & semi-mux D9's have 3 temperature sensors, (1 for the guage, 1 for the engine ecu & 1 for radiator fan control), whereas later cars only have one?

If so, might scotty need to change a different one?

[scotty73]

Please correcct me if I'm wrong, (again! ), but IIRC, don't D8 & semi-mux D9's have 3 temperature sensors, (1 for the guage, 1 for the engine ecu & 1 for radiator fan control), whereas later cars only have one?

If so, might scotty need to change a different one?

Oh crap now i come to think of it thats not the first time i've read that, fuckity f*ck it's wallet busting time again is it?... i think the one i changed was the more expensive one it's the one on the side of the engine a green one.

[Doggy]

Don't take that as gospel, cos I'm really not sure. Anyone?

[scotty73]

Don't take that as gospel, cos I'm really not sure. Anyone?

Sorry to dredge up an old thread here but last Friday for the first time since i started this thread it happened while the mrs was stuck in traffic and it was a hot day.

My question is when i have my mot if he revs the car up to temp to do emmissions and this warning flashes up can he fail it? and more important will it do any damage if he doesn't see it and keeps revving?

[jasper5]

Don't take that as gospel, cos I'm really not sure. Anyone?

Sorry to dredge up an old thread here but last Friday for the first time since i started this thread it happened while the mrs was stuck in traffic and it was a hot day.

My question is when i have my mot if he revs the car up to temp to do emmissions and this warning flashes up can he fail it? and more important will it do any damage if he doesn't see it and keeps revving?

The oil temperature is checked before the emission test is carried out....the engine oil is warmed to 80 degrees, water temperature is not checked on a diesel.

It can't fail if the stop light comes on, but they can refuse to test it or abort the test.

[scotty73]

Cheers Jasper, any idea what could be wrong then? one of the other sensors maybe?

[mjb]

Sorry to dredge up an old thread here but last Friday for the first time since i started this thread it happened while the mrs was stuck in traffic and it was a hot day.

Very much sounds like you're actually overheating.

If you've got access to PP2000, test the radiator fan.

If not, being very careful, remove the plug to each CTS with the ignition on. You'll end up with stored faults, but they won't need clearing. After you unplug one of them, the fan should spin up to full speed. It will be loud.

If the fan works, then either the thermostat's stuck closed, or it's a CTS. You can check the stat by getting the temperature up to about 75c then holding onto the top radiator pipe. When the coolant hits 84c, the pipe should get hot quickly.

Check the radiator fan fuses first though because it's easy. There's probably two(?) massive fuses in the small fusebox to the side of the battery. Haynes may help figuring out which one's which here...