Oil temp gauge, on 19D

[white exec]

Oil and coolant temp gauges now fitted to the 19D.
Coolant temp gauge AOK, and good to be able to watch thermostat and cooling fans doing their stuff!

Fitted the sump oil temp sender yesterday, into the M16 "second sump plug" port on the rear face of the ali (A/C) sump.
Single wire direct to pin7 on the 10-way.

Oil temp gauge slow to show anything. Needle lifts away from 'off' (similarly to the to other gauges) when IGN is turned on, but moves no further. QQ: How slow is oil temp to climb?

And (for test purposes), does anyone know the resistance values for the oil temp sender (OE 0242 50, Facet 7 3099, FAE 32080 etc) ?
I metered it before fitting, and it showed just over 3K at 18°C, but I don't have any other NTC figures.

[RobC]

I’m afraid I don’t know the resistance readings, but from my experience on a 16v the oil temp raises less noticeably quicker than the water, but after ten mins or so it should be obviously on the up!

[white exec]

Hi Rob,

Just done a 15km drive, ending with some steep hill climbing. 20C outside temp.
Water temp got to 90C, with fans cutting in, but oil temp showed just 75C.
As you say, oil temp much slower to climb; at least 15 mins on the road before it cleared 60C.

Used an IR thermometer on the sump, which showed 71C, and water outlet housing the same (gauge showing 70) — so both gauges reading fairly accurately, which is reassuring.

Never been too interested in oil temp in all these years!
Was expecting to find oil a good bit hotter than coolant, but maybe that's a performance/petrol/GTi thing...

[white exec]

Good bit of driving this morning, 17C ambient.
On way back, about 5km of fast motorway, then 9km of climbing up to our village. Oil temp gauge got to 85C by the end of that.
Not as hot as expected.

[RobC]

I do think that the 16v in particular is known as an engine that “runs hot”- mine certainly heats up quickly and the oil temp is always at least 100 under normal conditions. It’s even got an oil cooler under the filter (I don’t think diesels have this?).
I assume that a normally aspirated diesel will run somewhat cooler anyway.
Still- as you said: before you had a gauge you never gave oil temp a second one thought! It’s all good fun from a completist sake of course.

[David]

My oil temp gauge doesn't move much on my 1.9 diesel. The only time that I have EVER seen it high up is when I was driving down the A1 @ 70mph for about 30 mins when going to the national. Beyond that, it doesn't really move. Provided that your wiring is connected correctly, it'll be fine.

Hope that helps.

[white exec]

Thanks, David. Reassuring. That's pretty much what I'm seeing - not a lot of movement above 60C, unless the car is driven hard. As the oil has an important cooling function for diesel pistons, good to know it's not red hot.

Oil temp of 100C+ is frequently recommended, to drive off water vapour/condensation in the engine, but I've never had that problem in any engine running properly warm.

[David]

Thanks, David. Reassuring. That's pretty much what I'm seeing - not a lot of movement above 60C, unless the car is driven hard. As the oil has an important cooling function for diesel pistons, good to know it's not red hot.

Oil temp of 100C+ is frequently recommended, to drive off water vapour/condensation in the engine, but I've never had that problem in any engine running properly warm.

It's pretty much the same situation with mine. At first, I thought that it wasn't working, but I read somewhere that it doesn't really do much on a diesel, so I just left it and kept an eye on it, and when I went to the national it actually moved to around 100C.

It only seems to move if the car is driven at 70mph. For example, when I was out in it yesterday, I clocked up 40 miles, but I was only driving at a maximum of 50mph, & it didn't move from around 60C.

[deltic]

In my experience for the oil temperature gauge to reach 100C you needs to be doing illegal speeds for a prolonged period

[white exec]

Sounds about right!

[Kaapelimies]

In my experience for the oil temperature gauge to reach 100C you needs to be doing illegal speeds for a prolonged period

Or visit Germany.. The only country where BX*s engine oil has a smell too!