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MG MGF Technical - Oil temperature

Being a newbie to TFs, I'm concerned at my oil temp reading. It's normally just under 120* in traffic, rising to just over 120* on the motorway (at 70!). Handbook says OK, but seems a bit high to me? Either my sensor/ gauge is faulty.
Has anyone a resistance reading for the sensor?
Does heat shielding the exhaust flexi under the sump do anything?
Jerry
Jerry Herbert

Which model do you own Jerry? The TF160 has an oil cooler fitted as standard - it's a water/oil heat exchanger, which means that oil rises fairly quickly, but then is 'fixed' to coolant temperature. About 120 would be about right for this model (although I suspect that the gauge is over reading, as 100-110 would be the water temperature)
Rob Bell

Sorry, forgot to say 02 135, bog standard, 20k miles.
I was hoping someone might have a resistance reading for the sensor, before buying another to see if that was causing a "high" reading.
Also, heat shields on flexi?
Jerry Herbert

http://www.lame-delegation.de/mgfcar.de/sensor/
Will Munns

Hmm - in that case, I would say that your temperatures are on the high side - as in 'usual' driving, the oil temp shouldn't really exceed 100C.

Perhaps there is a sensor/ gauge problem here. There were certainly a batch of MY2000 MGF 1.8 sent out with an artificially high reading temperature gauge (there may be more on this on Dieter's web pages) - but I've not heard about this on the TF.

It would certainly be worth while taking your multimeter out and measuring the resistance across the sensor when the engine is up to temperature.
Rob Bell

Thanks for that link, I'll try it out next time I'm got the engine hot. If I find anything funny, I'll post back. I'm going to try a heat shield on the exhaust flexi as well.
Jerry
Jerry herbert

I think 120° reading is normal. The *truth* of the oil temperature will be lower, of course.

The sender is a quit simple low resistance NTC part only. Don't expect better then 10 to 20% precision on final reading of the sender and instrument setup (due to quality).

The temperatur faulty reading back in Y2000 was exceeding up to 150° at 70 'ish.

Regards
Dieter

Dieter

I'm having a 2003 TF. And mine also goes up to almost 120°C when driving normal. On the motorway driving a bit faster it also will go up to 135°C. I don't think that theres a fault. I've just one of those showing a bit more than others. Just have to know whats "normal" for your car and how to behave if anything "abnomral" happens.

Greetings,
Sven
Sven Angelmahr

Hi All,

I have noticed that after driving on the motorway for a while my temp gauge goes up to just under 150, which cause me some concern as it pushes the needle just off centre to the right.

I have a 2000 VVC with 22k and just had a 5 year service.

Is this normal?

Thanks in advance
James

I get similar readings too. A longer drive can have it up in the 120° area, maybe just over.

I figure, correct me if I'm wrong, that when a manufacturer fits a guage, they expect roughly centre to be roughly normal - take the coolant temp guage for example. It can be colder or hotter than "normal" and you'd like to know about this. There's no real logic putting "normal" anywhere but roughly centre.
Kev

Just tried to measure the resistance of the sensor, no luck. Got me foxed now as it appears to require only one wire as output(brown/blue)on wiring diagram. I've cleaned the contacts, lubricated with silicon grease, and will try it again. The only real way, I guess, is to remove the sensor and hang it in boiling water to check the resistance over a limited temperature range. I've also got a precision temperature gauge which I can compare the TF gauge. As long as I know what the TF gauge "means", I guess I don't need to worry unduly.
Would be nice to get it approx right!!
Jerry
Jerry Herbert

Does the sensor ground to earth throught the engine block?

Will have to look at some wiring diagrams when I get a chance Jerry.

James, 150 is a little high, but not that unusual on a VVC under sustained motorway oil. Depending on how you use your car, you may want to consider an oil cooler...
Rob Bell

Four wires to the sensor. Just tried a quick run after cleaning the contacts, no difference. Tomorrow I'll try my accurate temperature intstrument, on the same point as the sensor to see what it really is!
Jerry
Jerry Herbert

Mmm. Measured the oil temperature sensor housing today after a good run whilst showing 110*C on the instrument. My accurate electronic gauge said 85*C!!!!
I think I'll let it go at that, but will check the water gauge now as well.
Panic over, thanks for the useful links.
Jerry
Jerry Herbert

Dave do you still have your infra red temp gauge?

If so can you bring it to bedford. I would be intrested in measuring sump temp vs temp on the oil gauge.

We a few F's there and a bit of time we should be able to get a good statistical sample.
Steve Ratledge

Ok Steve - will try and remember to bring it :-)
Dave Livingstone

Thanks Dave, It was just a suggestion I didn't mean to impose.

But it might be interesting ;-)
Steve Ratledge

No imposition at all - I was intending bringing it to do some tyre pressure testing. I simply said that I'll _try_ to remember, because I know how bad my memory is :-)
Dave Livingstone

Might be useful for measuring temperatures with the EWP working too Dave? :o)

Goldfish 1 to Goldfish 2 - recommend a trail of post-it notes as a reminder... ;o)
Rob Bell

>>Goldfish 1 to Goldfish 2 - recommend a trail of post-it notes as a reminder... ;o)

LOL - it'll take more than that :-) I'll stick it in my helmet case now!
Dave Livingstone

Monday - just got busy :-)
Steve Ratledge

This thread was discussed between 23/05/2005 and 26/05/2005

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