Hello all,

I will be drilling and threading a new hole into my oil pan in order to "permanently" install the oil temperature sensor drain plug. I will be using a 0.5 inch drill bit to create the hole, then threading it with a M14x1.5 tap. I have read about others doing this same mod but I have not seen any comments regarding the best place for the new hole/oil temp sensor.

Is there an optimal spot for the new hole/oil temp sensor?

 

Oil pressure is much more important than temperature. Putting the temp sensor at the pan is a compromise and I don't see any ill in that. It might read a few degrees low but should well serve the intended purpose. And then what is the most accurate location? The oil temperature varies as it passes thru each vital Mini's internal organs, some high, and some low. Most important is to know where you mount it and interpret the reading accordingly.

 

I was thinking more along the lines of where in the pan to put the hole/sensor as to be out of the way of things like bolts, since the sensor protrudes a bit. As for accuracy, the sensor typically just replaces the normal oil drain plug, so I am fine with keeping it in the oil pan. Also, the wiring is already in place. I have read about others putting it in the oil filter housing.

 

Interesting project. I am new to Minis so please excuse my ignorance.

Does the Mini have an OEM oil temp monitoring circuit?

If not, did you add a readout to the dash?

What is the protocol for oil temp if it exceeds expected temp? Do you just slow down?

How often does the oil overheat?

Is the addition of an oil cooler another solution?

Thanks

 

Why go to all that trouble when you can use a Temp Sensor Drain Plug rather than the conventional drain plug? Removing it to drain the oil is no biggie.

 

The oil filter housing is very congested with the biggest constraint being the exhaust header. You will see if you look there carefully. Here is one great installation with Smith mechanical gauges you might find useful. The challenge with the oil pan is lack of thickness.

 

I already dropped the oil pan to change gasket, already have auxiliary gauges and wiring installed, and the thread count on the oil temp sensor is something like 4 which makes it prone to stripping. I also have the drill bit and tap tools, so realistically, all I need to do is drill a new hole, thread it, pop oil temp sensor in, and replace the original drain plug hole with a Fumoto valve. I'll never have to unscrew a drain plug again!

I am just looking for perfect placement of the hole. I won't be back at my car for two weeks which is part of the reason I asked the question. I am thinking directly above the current drainage hole could work. Also, I would think the top of the oil is better to get a temp reading from since the oil drips down directly from the engine and then works its way to the bottom to get repumped.

 

The attached image shows the auxiliary gauges I have which provide the readout. As for the other questions, someone else will have to chime in!

 

Here are two helpful threads I found. It also pointed me in the direction of where to drill a new hole. The new hole will be going to the left of the oil drain plug.

https://www.northamericanmotoring.co...p-point-2.html

https://www.northamericanmotoring.co...ml#post4246015

 

 

This makes sense because the dealers never stock the correct crush ring for the sensor drain plug. It also means you don't have to worry about the wire being so low.

 

Despite I now have a centre console gauge pod I will give you a unvarnished opinion as to the usefulness of MINI's oil temperature gauge. I only bought the gauge pod set for its gauge pod. IMO voltage and oil temperature is very low on the hierarchy of need in terms of usefulness when you consider to be more informed of the vital signs of the engine.

Does the Mini have an OEM oil temp monitoring circuit?
A: Other than this sell-up boutique JCW gauge kit, the DME does squad in monitoring oil temperature. Nor does it do anything when your oil pressure drop below fatal threshold, except lighting up the idiot light which, even for the most vigilant will likely miss until it is too late. For road cars, especially Mini with the oil filter housing drain back valve, knowing the oil pressure is infinitely more important than oil temperature. Why? You can infer the oil temperature from the coolant temperature for daily runabout. If you drive in a manner that you need to worry about oil temp, you probably should be arrested for driving dangerously and recklessly.

If not, did you add a readout to the dash?
A:


What is the protocol for oil temp if it exceeds expected temp? Do you just slow down?
A: Stop driving right pedal to the metal on public road, or pull over to see if you engine cooling system has gone kaputt.

How often does the oil overheat?
A: For driving on public road, your oil should never overheat. When it does it is caused by other issues.

Is the addition of an oil cooler another solution?
A: You don't need an oil cooler for driving on public road, or even for driving on race tracks for most unless you are driving at a very high skill level or in endurance racing. The biggest cause of catastrophic engine failure is loss of oil pressure (oil starvation) and engine overheating because of coolant system failure.

 

Finished my install - I used the following sensor:

 

Ditch the Fumoto valve, it ends up leaving all the sludge in the bottom of the pan. I've seen it in the Subies for years.

 

I beg to differ and see no evil. Oil sludge is what powers my Mini.

 

The pan designs are different as well as how the plug is positioned. I read up on that as well and I found that my Fumotos threads did not extend into the pan and that there would be enough angle to drain the oil well enough. This car is not my daily driver and it's not going to get a ton of miles between oil changes. I doubt I'll be generating any sludge, but I'm sure I'll pull the pan at some point and find out. I think the benefits out weigh the potential issues it might create.