Xantia oil temperature

davewithington · Post by **davewithington** » 07 Dec 2010, 18:33

Ok, this may be a stupid question, but what oil temperature would you lot expect a Xantia 1.9TD to run at.

I've not really looked at the oil temp. guage in the last 12 months, but something made me notice it a last week.

Is a temp. of 50 to 60 degrees normal? This is in normal day to day town running.

Post by **CitroJim** » 07 Dec 2010, 20:53

I would have expected it to have read about 90 once well warmed up Dave. My Activa and V6 run about around those figures but the Activa takes a lot longer to warm the oil than the V6 does.The difference is that the Activa, like your TD, has an oil cooler cooled by the coolant water whereas the V6 doesn't.

If the coolant is running at a cool temperature, as a diesel will tend to moreso than a petrol, then I'd expect to see a commensurate low oil temperature.

Also, the sump, being alloy and the sensor right on the front face, is going to get lots of additional cooling at this time of the year because the sump face is in the direct icy blast coming under the car.

Oil works best around 90 degrees. if the oil is too cool it never gets hot enough to evaporate condensation in it and it deteriorates; hence why oil should be changed more frequently in winter.

Oil is OK up to around 150 degrees and then it's too hot for it. Both the Activa and V6 can get quite hot, around 120 degrees, when wellied in the summer... This puts an additional load on the coolant rad.

What's your coolant temperature reading and how log does your oil take to reach 60 degrees? Your thermostat might be a bit sluggish and thus not only is the coolant overcooled but the oil too; the oil cooler has no thermostat of its own.

Post by **RichardW** » 07 Dec 2010, 20:57

Oil temp in my VSX TD used to run at around 80-90 with the undertray in place. Once the tray was removed the running temp dropped to about 60... I used to call it the hooligan gauge - it is much more sensitive to how hard the engine is working - thrash it hard and the oil temp goes up easily to 110 - really work it and I did see 130 - but that was real hooligan territory!

mendedit · Post by **mendedit** » 07 Dec 2010, 21:00

Quoting the Drivers Handbook it says-

Under severe operating conditions,in high ambient temperatures,the needle can approach the red mark.
Under no circumstances should the temperature be allowed to exceed 150 oC. if the reading reaches this level,slow down and if necessary stop and turn the engine off.
Check the engine coolant and oil levels as soon as it is safe to do so.
-----------------------------------------------------------------------------------

I believe oil above a temperature of this looses it's ability as an friction reducer, I think?

HDI · Post by **HDI** » 07 Dec 2010, 21:51

Oil should run at a minimum temp of 75 deg c, ideally 80-95 deg c on a continuous basis.
Running at persistent low temp will allow fuel and water to accumulate because it can't evaporate off, this breaks the oil down more quickly. Running at a persistent high temp causes the oil to oxidise more quickly and shear down from it's specified viscosity, this causes sludge to develop and the internals off the engine will become fouled with oxidised oil. Oxidised is a technical term for burnt.
Synthetic oils will resist oxidation better and longer than mineral.
For engines used on frequent short journey use oil changes should be at least 3 times more frequent than those used on long, that is more than 30 miles, journeys.

davewithington · Post by **davewithington** » 08 Dec 2010, 16:33

Fine. Nothing to concern me then.

I'd just not noticed what temperature the oil was running at before, and one does worry you know.

Reaches 60deg. quite quickly, but obviously the whole engine will take a while to reach proper operating temperature, 'specially since I live only a couple of miles from where I'm working at the moment. I do likwe to give it a proper run every couple of weeks, over 50 miles, just to help the oil do its job.

Oh, yes, only recently changed the oil and filter, and it will be changed again around March.

Ta chaps.

citroenxm · Post by **citroenxm** » 12 Jan 2011, 15:09

CitroJim wrote: Oil works best around 90 degrees. if the oil is too cool it never gets hot enough to evaporate condensation in it and it deteriorates; hence why oil should be changed more frequently in winter.

Just an note to make, this is shown by lots of "Mayo" under the oil filler cap and in breather pipes..

HOWEVER - This problem DOES NOT occur in DERV engines... A good reason why a DERV is a better short distance runneround then a Petrol..

The "Mayo" problem only seems to be a Petrol engine problem...

Paul

Post by **CitroJim** » 12 Jan 2011, 15:51

citroenxm wrote: The "Mayo" problem only seems to be a Petrol engine problem...

Indeed it is. Petrol cars "steam" far more in the cold weather than diesels and sometimes my V6 looks like it has a steam engine under the bonnet rather than a petrol one in the cold and moist weather.

I've spent many hours trying to work out why a diesel seems to produce less water vapour in the exhaust and engine breathers but I've yet to reach a satisfactory explanation...

HDI · Post by **HDI** » 12 Jan 2011, 16:04

Two differences between Diesel and petrol combustion are higher combustion efficiency and lower exhaust temperature with Diesel.
Maybe this creates less water ?

colski · Post by **colski** » 12 Jan 2011, 16:09

My TD Xantia barely reaches 70 and hasn't done so for a while (even in the summer months)

I'm getting the thermostat changed next week so i'm hoping that will improve things.

HDI · Post by **HDI** » 12 Jan 2011, 16:13

More than likely will but if not check the water temp sensor, they deteriorate and start reading low.

colski · Post by **colski** » 12 Jan 2011, 16:18

Thanks, i'll get them to look at that too