Oil Temperature sensor

Gentlemen, out there in T-Bar ether-land, your input would be appreciated.

The oil temperature gauge on my Abingdon has never moved off the left hand side of the dial, so I became accustomed to not knowing – and therefore not caring – about the oil temperature. For 25 years this was not a problem.

However, having - as many of you know – been through the trauma of trying to source a replacement VVC engine for the car which is now in deepest Texas I thought that maybe it was worth trying to have the oil temperature measuring system corrected, especially as the new engine was to be running in air temperatures of 95F and up.

Steps to date show that the circuit wiring is good all the way from the sensor connector to the indicator, so we know that it is a bad sensor.  

We tried the blue sensor off of the coolant side just to see what it would do and it lasted about 10 minutes before the gauge rose to very hot and the oil warning light (the one with the dripping oil can symbol) came on even though the oil was NOT overheating.

Using the advice given I looked up Rimmer and Brown & Gammon websites for part YCB100350, as being the right part for the replacement MEMS3 engine. Both sites said that this part had been superseded by part number YCB100420 – which is described as “coolant” and “water” temperature sensor, but NOT “oil” temperature sensor.  I ordered this part – it turned out to also be blue – and when it was fitted , it did exactly the same thing.

We took the single wire sensor off the old MEMS2 engine, plugged that one in just to see what would happen and it immediately swung the indicator to full hot, so that  sensor could be bad or is the wrong one. This sensor, we believe was brown.

Having started the search for a working oil temperature measuring system I am loathe to go back to having no idea as to what is going on with the oil.

Ideas please as to what to do next.

Thanks, Phil

I had a quick look on MGOC spares and their part number is MEK000020 and clearly states oil temp sender with confusing (to me) applications but might be worth a look. Tried to copy the listing sadly having just upgraded??? to windows 11 snip and sketch is hiding somewhere.

Many thanks for that speedy response. 

Question: I was told that the original sensor was a 1 pin plug, whereas the Rimmer website description is "4 pin plug".
Is this a problem / deal breaker? 

Or just replace the oil temp gauge with something more useful like a oil pressure gauge

Bitz' also quote a MEK000020 for Mk2 Fs and all TFs which would tend to further endorse it as the correct part.

I was surprised how many MEK000020 are on Ebay, most between £ 15 and £ 25.  They all have 4 pins in a round connector.  Is your plug like this but maybe with only one pin used ?


The only oil temperature sensor I can see with a single lucar type connector that could be accidentally swapped with a water temp one is the YCB100290 which was for the Mk 1 F only.

MEK000020 for Mk2 Fs and all TFs, which have MEMS3 ECUs. The other thing to note is that the threaded hole size in the oil filter adapter changed when the oil filter adapter changed at engine 18K4FJ31 646501 or 18K4FJ32 646201 according to the info on Dieter's website.

But as Cobber says, knowing the oil temperature is the next best thing to useless information.

As an upgrade path it could always be worth looking around for an oil pressure sensor which happens to match the same thread as the oil temperature sender. Then it would just be a pressure guage to fit in place of the oil temp one and run a wire between them. Oil pressure is so much more useful than temperature

Many thanks to y’all for your input.
Whilst an oil pressure gauge may be an upgrade, after all the hassles of the past year I really do not want to entertain the idea at this stage.
I have passed on the information to Tom Davis, my resident F Fixer, for his review and will move forward based on his feedback.
Thanks again,
Phil

This thread might be of interest to you. Matching pressure and temp gauges
In it I confirm the temp sender is 4 wire and also the different thread pitches.