Oil Temp On 2.8Q - 130 degrees From Idling??

[Siena]

Hey guys, just trying to clarify a point I'm not too sure of.

We know the normal coolant temperature range on a B5 is about 90 degrees, regardless of driving style, providing the thermostat is working as it should, and it's the correct one fitted.

Oil temperature however, is different. From experience, coolant temperature MAY rise if the engine's labouring on a very hot day - slow forward motion, in higher gears, uphill, towing etc. Again, if the thermostat is operating correctly, it shouldn't rise by more than a couple of degrees, so probably about 93 degrees.

With the low rpm though, oil temp is likely to be lower than if high rpm's are used.

Conversely, at high rpm / road speed, coolant temperature MAY drop slightly, again, with a correctly operating thermostat, not more than a couple of degrees, so maybe about 87 degrees. Oil temp however, will go the other way - higher. I've only ever experienced both coolant and oil temperatures rise together, if the coolant temperature rises excessively, due to too low coolant level, or a faulty thermostat, i.e jammed shut. Then, if the engine boils, the heat WILL transfer to the oil, and it'll go way too high. Oil pressure MAY drop over 150+ degrees, depending on oil grade used.

My concern here is, a guy has a 2.8, and he says his coolant will reach 90 degrees from idling, which you'd expect, with no forward motion. But his oil temperature reaches 110 / 120 at idle too! Now, the oil temperature in my 2.6 will ONLY reach that level, from sustained high rpm, on a very hot day, or the motor's boiling, either due to coolant loss, or a jammed thermostat. I also used to run an RS2-engined type 85 Coupe quattro, last power output from a 2.5 stroker was 426 hp. On track days, I HAVE seen temperatures reach 130 degrees, but it took a hell of a hammering, and a long time to get there. Regular driving on the open road produced oil temps of around 90 - 100 degrees.

I know there's an optimum oil operating temperature, after which the motor can be hammered, but I'd have said that'd most likely be between 75 - 80 degrees. I wouldn't have thought 110 / 120 oil temperatures are the optimum, as most cars under normal driving conditions seldom get that high.

Any opinions?

[Siena]

Wow, 12 views, and no comments??

[generik777]

I know my 2.8 rarely goes over 200 on the gauge which would be about 93 in celsius. And it's never gotten to that from just sitting at idle.

[Yaktizzle417]

What weight of oil are you using?

[Siena]

Yakt, it's not my car, just someone else's, who's adamant that oil @ 120 degrees, from idle is right?

[Siena]

Any more contribution guys? Doesn't have to be a V6 model, could be a 1.8T, 1.8 20V etc.