Coolant temperature sensor

[yorkshire480]

Well my 480 adventures continue! A few weeks back my water pump failed on a long incline on the M62 dumping coolant everywhere and producing much steam!
Despite my thinking I'd finally killed the car one new water pump and we're back on the road but this time with a certain degree of paranoia that it's overheating.
So I have two questions:

A: What are the normal operating ranges for the OIL temperature gauge readings? I'm getting around 87 around town and as high as 99 on the motorway.
I've not gone for more than an hours drive and not pushed it much past 70mph. What do other 2.0 owners out there get?

B: My coolant sensor display hasn't worked for sometime and ideally I'd like to get working again. It used to work but the single grey wire would always work lose.
However I can't get it working again. I've tested the impedance of the sensor before and after a run and there's big difference in the readings (sorry - can't remember the numbers) so although I've a replacement sensor I've not replaced it yet. Correct me if I'm wrong but it's a thermistor that takes it's earth connection from the engine block itself right? I know the block is earthed ok and the connection wire which I've extended and put a new spade connector on has continuity.

My feeling is at this point is that problem is probably with the IC end of things but before I start going down that road is my thinking right on this and has anyone any suggestions of what to look at next. I'm assuming the sensor is okay as it's not reading open and is unlikely to fail(?)

Ideally I'd like to monitor engine temp properly rather rely on the oil temp.

Thanks again.

[jamescarruthers]

Oil says stop at 140 degrees.

I've had a hard driven turbo up to 120 degrees I think, which is normal

[yorkshire480]

Great. That's good to know. I'm guessing the turbo engine might run slighty hotter(?) but 99c is still well within that range.

[brinkie]

A: What are the normal operating ranges for the OIL temperature gauge readings? I'm getting around 87 around town and as high as 99 on the motorway.
I've not gone for more than an hours drive and not pushed it much past 70mph. What do other 2.0 owners out there get?

If I am driving my 2.0 hard, it will rise up to 110 degrees when doing 180 km/h on the motorway (of course I am doing that on the German Autobahn and not on speed limited roads, no, not even with gale force 8 in my back, honestly! ), and the alarm is set at 140, so it seems you don't have any issues with cooling

B: My coolant sensor display hasn't worked for sometime and ideally I'd like to get working again. It used to work but the single grey wire would always work lose.
However I can't get it working again. I've tested the impedance of the sensor before and after a run and there's big difference in the readings (sorry - can't remember the numbers) so although I've a replacement sensor I've not replaced it yet. Correct me if I'm wrong but it's a thermistor that takes it's earth connection from the engine block itself right? I know the block is earthed ok and the connection wire which I've extended and put a new spade connector on has continuity.

Yes your assumptions are right. It is easy to test the IC.
If you earth the connector that goes to the sensor, the IC should say STOP after a short while (there is some delay). If you connect a 68 Ohm resistor from connector to earth, the IC should display something around 100 degrees. Leave it open and it should stay at COLD.

[yorkshire480]

That's brilliant. Thanks.
Having a means of testing things without removing the IC is very useful. I'm really trying avoid that if possible!
I'll have a look but I doubt I've got anything as high as a 68ohm resisitor lying around so I'll have to order one.

[brinkie]

You don't really need the 68 ohm resistor, it's just for calibrating purposes. When grounding the spade lug sets off the IC alarm (flashing STOP on display), and subsequently leaving it floating eventually "drops" the temperature to "COLD", then you can rest assured both the wiring to the IC and the IC itself are functioning admirably

[yorkshire480]

Excellent information, thanks! The sun's out here today so that's gonna get done this afternoon.

[Norm57]

Hi hope you got it sorted. My 2ltr runs at about 87-90 oil temp round town water a bit higher,on a run anywhere between 95-105 water a bit lower,give me a shout if you need a hand

Cheers Norm57