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MG MGF Technical - What is fair about oil temp?

What is fair about oil temp?
Crossing at about 130k/h for a few minutes the oil temp reaches 120C, sometimes a bit more. Is that normal or too hot?
Mike (F1.8)
JM Vega-P.

i dont know if there is any particular figure for it, as each car /oil/guage is different but i would have thought from what i have read on here that around 90c would be more usual


... for 60-70mph in british weather.
Will Munns

Mine's running hotter 100-120'ish, but it could be the oil wants changing, due in a couple of months.

I would be interested in any informed comments concerning normal operating oil temperatures - being somewhat sensitive following an HGF in my then two-year old F.

I now have a one year old TF and once "warmed up" the oil temp. is always just under the 120c - regardless of whether hard driving or steady 70mph motorway driving. That's higher than I've seen mentioned on other threads. Is that a worrying level - it's never any different?

Do I get the impression that a steady temperature reading that isn't wildly high is better than a fluctuating reading? Are the gauges not overly reliable anyway?

Thanks in advance

mine just seems to rise to about about 75c and stay roughly there whatever the speed or weather...

Still not informed, I know..,
but mine has never had coolant problems, is serviced regularly, and hits 110C every day when I do a blast on the motorway.
I have seen 120 on more hot or heavier driving days..
.. I reckon 120's gotta be okay..

.. do look after your oil changes though.. they are important on the K's.
N Hillier

Hi. I own an MG Tf 135, and is just when the oil temp reach near 120C when I start to run really fast. In our warm (sometimes hot) wheater 120 is ok.

Mine heats up to 110C on normal highway use. On hot days OR long fast runs 120C. On hot days AND long fast runs 122-124C

Thanks to this fourm I fitted the resistor the value of which has escaped me for the moment. Without this I could see 150 at times. Now fitted the guage sits at 120-125 degrees at motorway speeds and will reach 120 after a reasonable ordinary drive.

The other thing is that generally people say not to exceed 3000 rpm until you see 90 degrees on the guage. With such a wide range of temperatures being disclosed it would make you wonder how accurate are the damn things. I almost all of the time adhere to this rule especially after HGF.


Lot of responses here...... well mine sits below 100 mostly, unless i'm REALLY caning it on the motorway...... and then it reaches 120..... but drops about 5 minutes after returning to a steady 70mph in 5th back to 90ish.


Thanks for the responses to my posting.

I guess my main query is that in the light of the varying "normal" readings we all experience as reported on this and on other threads on this subject - can the oil temperature gauge provide a trusted reading? Is it a reliable indication that the engine is operating normally and efficiently or that something is about to go wrong?

After all what some would see as an unsually high temperature - say 120c - would appear to be a normal operating temperature both by myself and others here.


Another question I'd like to know the answer to is why do we have an oil temp gauge instead of an oil pressure gauge?

Tim Jenner


I think the oil temp gauge is only useful in relation to itself - so if your car has no appearent cooling problems for a long time, the particular behaviour of your temp gauge is normal. Keep an eye on it to see if starts acting differently - only then something might be wrong...
Comparing to others is no use, since some run normal on 75C and others on 120C. I do wonder about the postings stating that the oil-temperature changes significantly after an oil-change. This suggests a different kind of oil causes the temp to drop/rise 20C! Comments on this anyone? If this is true, it might help prevent HGF?

This thread was discussed between 02/06/2003 and 05/06/2003

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