SC VR6 Oil Temp.

[ourfamo4]

My friend just bought a 98 VR6 GTI with a C2 Stage 2 Vortech supercharger. The setup is good for about 250hp to the wheels. Running around town the oil temp stays around 208*-215* F, normal for a VR6. Once on the highway it creeps up to 230* f and stays there. We're running M1 15w50 currently at 3-5 month changes.

Does anyone have an opinion on if we should add on a external oil cooler ? Or will the engine be OK the way it's been for 4 years with the previous owner ?

Thanks

 

[porcupine73]

With a good oil and regular changes you should be OK. Some LC20 might help in this application. If you get an external cooler, just get something with like a 180 deg. F. thermostat to prevent overcooling.

Is the supercharger oil cooled at all?

 

[ourfamo4]

Thanks for the reply,

No, the supercharger receives its oil directly from the engine oil. Its directly connected to the oil pan, which is where all the heat is coming from. Also I think the charger needs a intercooler.

 

[porcupine73]

Yes that can add a lot of heat. Another option might be I have seen these oil coolers that sandwich between the filter and filter mount point. Then you run coolant lines say from the heater core/bypass return through it. Not sure if that would give better heat rejection than an external cooler; probably depends on the cooler size.

 

[Thermo1223]

Why 15w50?

I see no reason sticking with the factory approved 0w40 would hurt anything.

 

[ourfamo4]

The 15w50 is what the PO was using, so we just stayed with it. I'll go with 5w40 Pentosin next change, then compare the UOA.

Thermo; How's the Rabbit ? We just bought a 07 MK5 Jetta 5spd and love it.

 

[Gary Allan]

Those temps aren't out of whack for sustained high speed. They retreat, I suspect, as soon as he takes his foot off the pedal. Many engines run in the 220F range at 65-70 mph. It's just the time compression of the combustion process intro'ing more btu's than can be rejected in normal throughput via the oil.

Doesn't this have a coolantil heat exchanger like most VW/Audi engines?

 

[Thermo1223]

Quote:

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The 15w50 is what the PO was using, so we just stayed with it. I'll go with 5w40 Pentosin next change, then compare the UOA.

Thermo; How's the Rabbit ? We just bought a 07 MK5 Jetta 5spd and love it.

---

Nice UOA tells the tale, honestly the Rabbit....well it's trash j/k

As much as I would have loved my wife to get a 5 speed...well auto it was. Very nice car though I love it as well.

 

[shanneba]

The ODBII computer may be programed to increase the coolant temp at low load highway speeds. My 2003 BMW 330Ci runs at a coolant temp of 200- 205 F on the highway, if I get into a stop and go construction area the thermostat opens more and the engine starts to run around 180 - 190. As soon as I get back up to speed the coolant temp goes back to 200+.

My computer shows an oil temp of about 225 on the highway, but it cooled down to about 206 in the construction. I was monitoring this with the ODBII software on my last trip to Indiana.

It also seems to run the engine cooler if I run the car harder such as during an autocross.

 

[porcupine73]

Interesting. So it has some sort of ECU controlled thermostat? That'd be cool. Many automakers do favor higher operating temps because of increased efficiency.

 

[shanneba]

The Bently manual for the 3 series BMW has a section on the DME controlled thermostat.

It says the the thermostat is electrically heated and controlled by the DME. The ability to control engine coolant temp at idle and part throttle operation results in improved emmissions and performance.

The ECM also start the electric cooling fan at 20% of its max speed on a cold start, shuts it off and measures the voltage output of the motor as it spins down to cofirm the motor is still functioning properly.

It has been interesting to monitor my engine computer with the Auto Enginuity software. It allows me to record the ignition timing, injection duration, engine speed, oil temp, coolant temp in the engine and at the radiator outlet, vehicle speed, RPM and many other sensors.

 

[ourfamo4]

The VR6 does have a standard oil cooler like every other VAG engine. But I was just worried seeing that high of a number. I guess on the next run we'll hook up the VAG-COM a do a little graphing. Here soon it's going to get a sofware update because it seems to be running super rich. Well thanks for all the help.

LONG LIVE THE "VW"

 

[eljefino]

That's one awesome beemer. I've hypothesised myself that a touch more heat might be worthwile for efficient cruise, if one can block a thermostat or slow down an electric water pump. Am sure they thought through the effect on metal expanding and contracting, though it's no worse that waiting in traffic for the electric fan to eventually come on.

 

[TurboJim]

It would be interesting to see if you experience an oil temperature drop should you switch from 15W-50 to something like 0W-40.

 

[mechtech2]

Use a thinner oil, like an x-40, and your highway temps will drop.