Longnose

I have a 2002 C4S with 96,000 Kms, and I live in Vancouver, BC, Canada.

During the winter months, I find a small amount of yellow foam that accumulates on the inside of the oil filler cap. I do not notice it during the warmer months, only during the colder months.

I do not loose any antifreeze. What do you think? No big deal?

FRUNKenstein

Basically normal. Look here:

https://rennlist.com/forums/996-foru...ound-this.html

gnat

Search is a wonderful thing.

Drive your car more and for longer non-stop trips. Your trips are too short so your engine isn't getting fully up to temp and/or for long enough to burn the impurities out of the oil.

bcrdukes

Hi Longnose,

I'm in Vancouver as well (there are a few of us on Rennlist from Vancouver.)

Like you, I don't drive the car much in the winter. I would suggest you drive the car at the very least to operating temperature and oil pressure to 1.5 bar. Any less, the car isn't fully warmed up and will result in the foam you noticed. I barely put on 3000km in 2015 and there was no foam at all. I change the oil once a year as a preventative measure.

Longnose

Wow, you guys are fast, thanks. So, let it warm up more before driving, roger that!

Glad to know there are a few of us in Vancouver!!!!

bcrdukes

Well, you could do that, but I think general consensus is fire the car up, give it a minute or two before taking off. And if you do, keep the RPMs low, like under 3000 - 4000 RPM. Some clowns out there like to blast off into space when the engine is cold (not sure why.)

What I mean is, drive the car further and longer if possible until the car is properly warmed up, and by that I mean:

- Needle on temperature gauge is @ 190 (give or take 5 degrees, basically between the 8 and 0.)
- Oil pressure on idle is @ 1.5 bar

Just keep in mind, this is a general rule of thumb, and it works for me, especially in Vancouver. Perhaps we should grab a coffee sometime. Send me a PM.

gnat

Absolutely not. You get in, start it, and drive off. Never "warm it up" by letting it idle.

You have to drive it longer to get it up to temp.

Gonzo911

According to our resident expert, that may cause bore scoring, especially in colder climates. Start and go.

gnat

Not a minute or two. Long enough for the idle to drop (30 seconds or so?) at best. Also 2500-3500 is probably a better range tending toward the lower end.

That is the water temp and mostly irrelevant. The water temp will be up to operating temp in a couple of miles (based on ambient temp) but the oil takes much longer. Since Porsche decided a gauge for the oil temp wasn't important, the oil pressure is the best you can do.

As an example it was 18 degrees here this morning. My Cayenne's water temp hit it's operating level at about 3 miles but the oil didn't hit it's peak until about 12 miles (it peaked at 5 degrees less than normal but wouldn't go up anymore over the last few miles).

Quadcammer

Debatable. Shifting at 2500rpm will drop the rpms quite far on certain shifts. You really don't want to be applying a lot of load at low rpm when the car is cold (or ever really).

Id say 3000 to 3500 is a reasonable target.

gnat

Upshifting at 2500 won't keep it between 2500-3500

You are correct about not lugging the motor, but 2500 won't do that in the 996.

Generally I "cruise" in the 2500-3000 range and upshift around 3000-3200 while warming up and that keeps me right in the range. Not lugging, not over excited, and still plenty of power for normal driving.

brianwad

I believe the science of the white/yellow coagulant in an oil filler cap is as follows...
1 When damp air comes in contact with a cold metal surface it makes the surface wet. Internal engine surfaces get wet in cold damp climates.
2 The water so formed drops into the lubricant and emulsifies (combines) to make the gunk when churned by the engine rotating.
3 The gunk collects on the oil filler cap when the engine runs and because the cap is much cooler than the engine it does not turn back into a vapor.

Therefore, because the normal operating temperature of the engine is higher than the boiling point of water, the operating of the engine at its normal temperature for long enough will boil off the water in the emulsion.

Failure to boil off the water reduces the quality of lubrication.

extanker

dude .....short version....no big deal. wipe if off if it bothers you and drive the car more if you can. OR keep reading the expert drama queens HBO delta

Chiamac

A person really should keep the rpm's low, as the differences in oil temp, and the way that the piston and cylinder heat up all contribute to bad things happening.

Not that a person should let these idle up to a hot temp, but having them sit around for a few min isn't the worst thing ever, gives things a chance to get used to moving again and the oil a chance to flow.

http://jalopnik.com/yes-warm-your-da...old-1678251730

gnat

Jalopnik for technical advise? The same ones that brought us such insightful hits as the $8500 996 and using your smartphones as brake pads in an emergency (also on a 996)?

I thought better of you Chiamac