Vag tune, now shows oil temperature. Friction

[L0U]

The oil temperature may be a good method for how far into breakin the motor is. On my A3, it consistantly runs high 90s, like 96ish here in canada. I know before the oil light comes on that I am getting lowish, because the temperature rises to 98s to sometimes 100.

As for the S4, I was missing the oil temp reading for trending purposes. Last night it was Vag coded in, and I have now noticed that the S4 is 2 or 3 times faster than the A3 in getting up to temperature. I get heat in 1 minute. The reading does not go as low as the A3 (it reads minus even), instead it is irrational, and comes live at 60 degrees C. It took 3 mins of town driving for coolant to hit 90, and 6 mins for oil to hit 60.

So with 300kms on the new S4, temps topped out at 108 last night, and would fall and rise around that temp depending on road speed.

The point?

the extra 10 or 12 degrees C this engine is running at vs. my A3 is either designed in, or additional friction from a tight motor. I am not worried about 108 temps, because above 100 actually keeps moisture out of the oil, by boilling it off and crankcase venting it.

If oil temps fall as compared to my A3 with more mileage, I'll post the findings. Outdoor temps have a small effect, so the A3 is my constant.

[NWS4Guy]

Good info L0U, thanks!

I'm not at all surprised that with a SC, this will get up to temps faster. For the temps overall, I have to wonder a few things:

You mention tightness, which should contribute and overall it should drop as things loosen and the bearing races get worn in.

Do you know the oil which it came with? (i.e. synthetic, weight?) This can have a notable impact on temps as well.

[L0U]

Not sure, I suppose the S4 may have a different wieght for its first stint before the 8k kms service vs. the Audi serviced A3. Someone else mentioned that they're S4 retained heat, being hot after being parked for periods of time. It sure does heat up fast. So far I have not noticed that it cools slower. (might be hotter to begin with, when you shut it down)

[NWS4Guy]

True, not sure about what the A3 had, but this is an aluminum block and heads, which conducts heat VERY well compared to iron, so this will help the engine heat up faster, though it should also help it cool faster too, so this is odd.

[LODOSS]

Do you have to take into account the total volumn of coolant and also oil as well as the temp when they start to circulate?

[L0U]

Do you have to take into account the total volumn of coolant and also oil as well as the temp when they start to circulate?

The oil change volume is 6.2 litres on the S4, the A3 is around 5. Coolant volume should be larger on the S4 as well, but I don't have the numbers.

more volume deffinitely takes longer to heat all of the mass. I like the fact that the S4 heats it all quickly. You can get on the power sooner in the morning.