Expected oil temps

[tomwood]

Am interested to find out what other people are measuring their oil temps to be on cars with a similar setup.

Spec is R400d with roller barrels and dry sump. I have an oil cooler fitted as well as the standard ford modine.

i have recently carried out the tried and tested switch mod that allows me to switch between water/oil temp using the existing coolant temp gauge. My oil temp sender is in the dry sump tank and was fitted by Caterham so assumed to be the standard temp sender that they sell.

since doing this mod, even in warm conditions such as we had yesterday I’ve yet to measure more than 80 degrees or so and this was after a 2hr drive up the M40 so fully warmed up. Does that sound correct?

interested to hear what others are getting:

- under normal road driving

- while out on track on a hot day

Essentially I’m trying to work out if the reading I’m getting on the gauge is accurate and representative or whether the actual oil temp is likely higher than is being indicated on the gauge.

Tom 

[Jonathan Kay]

My oil temp sender is in the dry sump tank and was fitted by Caterham so assumed to be the standard temp sender that they sell.

Even if it's the standard unit do you know that the resistance range matches your instrument (or the sensor in the water system)? That could be checked either from the spec/ part number or experimentally.

Jonathan

[ScottR400D]

Mine is 2015 R400D with RBTBs. I did the switch mod 18 months or so ago and the sender, which is exactly the same as the water one, is fitted low down in the triangular oil tank. 

Normal ambients I get maybe 65c. On track, up to 85. 

Recently on the road it’s been up to about 75c.  

It sounds low but is after the oil has been cooled and just before it’s going to be pumped back into the engine. 

Assuming the oil will heat up and be cooled by 15/20c as it is pumped, it seems about right to me. 

 

[John Vine]

I've a 2008 R400D with RBTBs and a wet sump.  I did the switch mod just over six years ago, using the same sender (71167) as the coolant one, and fitted in the big blue sump plug that holds the finger filter in place. In that position, I imagine it sits in the hottest oil region.

On the road, I typically get 75-80C on the standard CC gauge for coolant, and 75-100C for oil.  100C only comes up when making good progress on a hot day -- like today, in fact.  I also have the standard Mocal oil cooler in front of the rad, but it's 100% masked off.

I've just noticed that the CC Online Store says for 71167: "Caterham gauges only. Part has recently changed. Replacement for original part."  I'm assuming that my two are of identical spec, but I've not measured resistances.

JV

[john milner]

A completely different engine (K Series) but once warmed up my oil is generally just over 80C. Traffic jams will raise the water temperature and sustained speed (e.g. motorways) will raise the oil temperature but steady progress will roughly equalise the temperatures at 80+C.

Before I was able to check the oil temperature I did consider the various cooling/warming options but in my case it would be a waste of money and just something else to go wrong. I now look on the odd 100C oil as being a good thing that should boil off any water that may have found its way into the lubrication system.

[ScottR400D]

100c shouldn't be a problem at all, measured in the right place, though it’s not necessary to get that to boil off an water contamination, it’ll evaporate at much lower temps. 

I got my temperature sender on line for a few £.  Genuine VDO, same resistance and temp range but with a M5 stud to take a ring connector rather than use the spade pushed on to the odd disc on the sender. (Never understood why CC did that, though I see they’ve now changed to a proper spade terminal). 

[tomwood]

Thanks for the replies gents and sorry for the slow response, I was fortunate enough to be at Silverstone yesterday so a good chance to get some sample data whilst running on the GP circuit with, lets face it, some of the hottest temperatures we are likely to get here in good old Blighty.

After 30 mins of running, the oil temp peaked at a steady 90 degrees as indicated on the gauge. It held firm there and didn't rise over this level. I was physically melting under the conditions but the car held-up brilliantly.

I hadn't appreciated until Scott mentioned it that this temperature reading, as taken from the tank, is post-cooling so an allowance needs to be made as suggested. If 15 - 20 degrees should be added then this suggests I'd have been running in the 105 - 110 degree range in terms of oil exiting the engine.

So I think the gauge is probably working exactly as it should, I simply hadn't realised it was taking the reading after the oil is cooled.

Regards

Tom