6 replies to this topic

[lewBlew]

Hi everyone. I need to replace both of these on my car - coolant temp sensor and oil pressure sender - standard 1991 Mayfair 998

I've done temperature sensors on Capris before and it was quite easy, whip it out and put a new one back in and just 'cope' if a little coolant comes out. But the Mini one is larger, can I still do this?

The oil sender I've never done before. As above, can I just take it out and swap it or will it make an awful mess?

Thanks

[Doz1971]

Just done mine. Be quick and you'll lose less than a pint of coolant. Be aware the old coolant sensor is made from brass so is quite soft. Get a socket on it rather than a spanner. Top up after.

When doing the oil pressure switch, you should only lose a tiny drop, as long as the engine isn't running at the time !!

[lewBlew]

I'll make sure to turn the engine off then!

Thanks for the advice. I was just worried doing it with liquid pouring out might stop it being watertight but I'm sure the thread is long enough.

[dklawson]

Why do you need to replace them and in particular why "both"?

The standard Mini oil pressure gauge is mechanical, not electric so there is no sending unit. There is an oil pressure switch on some cars. They do fail but not often. What symptoms that make you want to replace it?

The temperature sending unit will loose some coolant but as you said, just top-up afterwards and you will be fine. Is that sending unit known to be bad or do you just suspect it? What symptoms make you want to replace it?

EDIT: The Mini temp sending unit will also be different than what you may be used to in that it seals/seats with a tapered profile towards the bottom of the part. It doesn't seal on the threads as such. However, a wrap of Teflon (PTFE) tape on the threads won't hurt if you are worried about leaks.

Edited by dklawson, 20 July 2012 - 04:24 PM.

[lewBlew]

Thanks for the info. Reason for replacement is 1. my temp gauge occasionally doesn't register anything, then it will, then it won't. I can only assume replacing the sensor would be the easiest thing to fix first. And 2. My oil pressure warning light occasionally comes on about 5 seconds after the ignition/alternator one. I've recently changed the oil and this didn't fix it. I've been advised to change the switch and go from there.

[dklawson]

That makes sense then. The oil switch is certainly easy and painless. A bit of Teflon tape on the threads will insure a good seal.

For the temperature sensor, replacement may indeed help but if it doesn't, be sure to check the wire from it to the gauge. Also keep your eye on the fuel gauge. If it is also acting up in the same manner, the problem will be with the voltage stabilizer or the supply to the stabilizer.

[lewBlew]

All done, was easy peasy but confusing as with both the oil and the temperature sensors, the socket size was different on the ones I took out and the ones I put in! They fitted fine though, and the temperature gauge at last is no longer lying to me (goes up to about a 1/3-2/5 on a run which is nice instead of sitting near the bottom). And no leaks so far..!