Oil warm up time (not as slow as you think).
 

Conventional wisdom says it takes twice as long for the engine oil to reach operating temperature as the engine (coolant) temp. That has always been generally true....until now. I have been monitoring this in the Boxster and it's way different from any other car I've owned.

First off, for monitoring I used the Durametric OBDII reader for Porsches. It's wonderful and it allows me to read all of the codes for the alarm system, airbag, A/C-heat system along with the regular OBDII codes. It also allows me to see real-time stats.

So here's what I observed. The normal operating temp for the engine is at 195F. The normal operating temp for the oil is 200-205F. As the engine temp rose, the oil lagged behind a little. Once the engine got above 180F, the oil temp started rising faster. As soon as the engine reached normal operating temp, the oil was 200-202F. I have watched these readings several different times from first morning (stone cold) start to a lunch time start when it sat for a couple of hours and it's always the same. I'm guessing the oil squirters allow the oil to flow much better and it warms up faster with the engine.

So bottom line seems to be the engine temp and oil temp reach their normal operating temp at pretty much the same time. :dance:

For a side note...the white line to the right of the 180F mark is 235F. I always thought it was halfway between the 180 and 250 (overheat) mark so that was a surprise when I ran it hard and got the temp up to that line. Just a little FYI. :cheers:

John, I believe it would be prudent to add a little disclaimer in that last statement you made... for those of us who have swapped our gauge faces and no longer have totally accurate needle placement, despite our best attempts!

Currently, my temp needle hangs a little to the left of where everyone else says their needle sits during normal driving.

Are the replacement guages different or is it just difficult to line them up perfectly?

So in lieu of the technical stuff whats a safe approx. time for me to warm up the 986 in the mornings before I drive off?

Maybe 10-30 seconds! The engines warms up best by driving it. Once it has come up to temp, then you can drive in the higher RPM range. Stay below 4,000 RPM until engine temp is in the normal. Ideling (excessive) is just a waste of gas and could even mess-up the cars sensors.

Most knowledable folks recommend that you let the car sit for maybe 30 seconds at most. This is enough time to put on your best, adjust the mirror, lock the doors, close the garage door etc. Then, drive the car moderately until it is fully warmed up. For most practical purposes this means do not hammer the car until the the engine coolant is at normal operating temp and the drivetrain has had a chance to warm up as well.

Thanks for the quick replies guys. I always thought that I needed to idle the car in order warm it up.

It's a very common misconception!

Hi,

I agree that under temperate conditions above 40°F that 30 sec. is usually enough time to float the crank and get the oil flowing and the pressure up and stabilized. Below this temp, I'd give it a little more time.

But, you want to keep the revs down, not so much until the coolant comes up to temp, but for the tranny and tranny fluid to warm up. This is a much more viscous fluid and needs more time to heat up and flow than engine oil. Also, it's hard on the synchros to slam them when they're cold, shift with some delay, don't force the shifter. Using the coolant temp is probably a pretty good gauge as to when the tranny is fully warmed up. Hope this helps...

Happy Motoring!... Jim'99

Jim is dead on!