This is on the 95 3100 Lumi I've got.. You may remember it from when I replaced the water pump a couple months back and couldn't get the system bled.. Anyway, I was fixing to go on a trip yesterday and I was checking the fluid levels and for the hell of it I decided to have a look at the oil cap.. I pulled it off and I noticed that there were some white spots on the ring around it... Damn it.. I rechecked the oil level and it doesn't appear to be elevated.. I checked the coolant, and it seems normal (I filled it to just below the hot line when I did the water pump a couple months ago, and it's about 1/2 to 3/4 of the way between them still (it seems to fluctuate in the resevoir depending on how cold it is outside???)). Something else I might add, is that this car rarely gets driven over 7/10ths of a mile at a time (that's about how far it is to work), so the engine never really warms up.. I ran the car for a minute yesterday after I checked the oil cap, and I didn't see anything on it that time, but it didn't run for long. I guess my question is, what is on the oil cap? Is it possible that it's condensation or something from not running the motor for long, or do I have coolant in the oil?

Thanks,
Will

The white spots are probably condensation on the inside of the motor. If it doesn't come up to temp it won't boil off any water that gets in there. I would take the car out once a week or so and just drive it around at operating temperature to get all the crap boiled off.

A car that isn't driven very much or is used mostly for short distances will accumulate a surprising and sometimes alarming amount of condensed water in the crankcase during cold weather. The water will usually tend to evaporate out during an extended period (more than an hour) of highway driving.

As an example, my old Porsche 911S used to accumulate more than a quart of water in city driving during the winter, and the oil level would appear to drop dramatically during the first few hours of a cross-country trip. It was just the water boiling off.

quote Originally posted by Marvin McInnis: As an example, my old Porsche 911S used to accumulate more than a quart of water in city driving during the winter...

Now that is amazing. I had no idea so much condensation could build up.

quote Originally posted by Patrick: Now that is amazing. I had no idea so much condensation could build up.

Now that is amazing!!! Thanks for the replies guys!

-Will

If you had water in your oil it would be a milkey brown and you'de probubley notice it right away.You car would allso run hotter (in the red zone).I agree condensation.

quote Originally posted by Patrick: Now that is amazing. I had no idea so much condensation could build up.

I think it was probably an unwanted side effect of the 911S's air cooling, dry-sump lubrication system, large oil capacity, and two oil coolers. All 911s have (or used to have) an oil level gauge. By design, the gauge was only accurate at idle but you could still get a rough idea of the oil level when cruising.

I always carried an extra quart or two of oil on a winter ski trip. Starting out with a full oil tank, you could see the oil level shown on the gauge dropping during the first several hours of highway driving. I often would add a quart of oil at the first gas stop (~300 miles) to replace the water that had evaporated out of the system. After that first gas stop the oil level would usually stabilize, and I wouldn't have to add any more for the rest of the trip. God, I still miss that car.

[This message has been edited by Marvin McInnis (edited 01-12-2008).]

Well, I drove the car around town yesterday for about 30 minutes to run some errands and kill a bit of time.. Just for shits and giggles, I pulled the oil cap when I got home.. This is what it looked like:



Kinda a yellow color with some tiny bubbles in itaround the top of the cap.. There was also a bit of clear water that ran from around the ring of the cap when I tilted it to the side and shook it a bit.. After it set for about 30 minutes I went out and checked it, and the oil cap looked normal color again.. Is this bad?

quote Originally posted by 88red4cyl: Is this bad?

Yes, this is the worst close-up picture of an oil cap that I've ever seen. Get a better camera!

quote Originally posted by Patrick: Yes, this is the worst close-up picture of an oil cap that I've ever seen. Get a better camera!

I've got a better one somewhere, but my wife doesn't know what she did with it.. I took that with my cell..

quote Originally posted by 88red4cyl: I've got a better one somewhere, but my wife doesn't know what she did with it..

Lose the wife, find the camera.

quote Originally posted by Patrick: Lose the wife, find the camera.

lol Well, even if I find the camera, the oil cap looks normal brown color again, and to get it to look like that again, I'd have to drive the car for a while and I don't want to if there could be coolant in the oil...

If your coolant level isn’t dropping, I'd say it's just normal condensation in the crankcase.

quote Originally posted by Patrick: If your coolant level isn’t dropping, I'd say it's just normal condensation in the crankcase.

That's the thing, I don;t know if the coolant level is dropping or not.. When I filled the resevoir 2 months ago, it was 60° was was about halfway between cold and hot when cold.. Now that it is 0-10° it is barely over the cold line.. When it's been run though, it goes up a little over the hot mark like it did before.. Is it possible for the engine and radiator to "suck in" more coolant when it's cold like this? And is it normal for the condensation to make the yellow color and bubbles?

[This message has been edited by 88red4cyl (edited 01-21-2008).]

If you were leaking a lot of water into the engine, then you would see a lot of white on the inside of the valve cover and also on the cap. A little on the cap is not bad (can't see the photos). My 3400 engine is on it's third intake gasket set... This last set is supposed to fix the problem.... I will believe it when I see it.

Anyway, the leak was noticable as you could see the white inside the valve cover.

J.

quote Originally posted by jaskispyder: Anyway, the leak was noticable as you could see the white inside the valve cover.

I can't really see into the valve cover that well, but what I can see looks brown... Since you can't see the pics, the enclosed circle (the flat part of the oil cap) was covered with a yellowish gunk I would call it that had some bubbles in it.. Nothing else anywhere I can see...

Hm.. I was driving the 99 Lumina LTZ today (3800 Series II) and I decided to check the cap on it.. It's got the same yellow looking crap on the top of the cap as the other Lumina does.. And this one gets driven even shorter trips (like go a half mile, sit all day, go back a half mile) than the other one does.. It was dried on the 3800 though and wet on the 3100 cap.. The oil cap had quite a bit on it and it was very hard to get it to turn off of the filler neck... There was also some yellow gunk in there.. Must be because I drove the 3100 for about a half hour before I checked it..

Is this dried yellow gunk condensation as well?

Well I took the 3100 out for a drive today and drove her around for about 15-20 minutes.. About the length of time for the gauge to get up to the middle and stay there.. Then I took some pics of the oil on the dipstick and crankcase, and then a better one of the cap. I know that the oil and water will blend if they are both present and look like "chocolate milk" so I thought I'd post and let you guys see what ya thought.. Now on with the pics..





And here's a better one of the oil cap.. It looks dry in the pic, but it was wet on the cap..


So what do you guys think? Did I even warm it up enough to tell anything.. The reason I'm posting this is because when I tasted the oil right off the cap, it almost tasted a bit sweet, but when I tasted it again it just tasted like crap.. So I thought I'd throw some pics up and see how it goes.. Oh, and the oil has ~1500 miles or so on it, Castrol GTX 10w30..

quote Originally posted by 88red4cyl:

It's REALLY difficult to tell by your pictures, but I see no evidence of any milky looking substance on the dipstick. I'd say any water in your valve cover/crankcase is just normal condensation.

quote Originally posted by Patrick: It's REALLY difficult to tell by your pictures

Yeah, I can't get my camera to focus at all... So I am having to try and hold it the right distance away so that it is at least somewhat viewable.. Also, my hood prop strut decided to blow up this morning, so I was holding the hood open with my back and taking the pic at the same time..

I would say there is nothing wrong with the engine. BUT, hard to tell from photos. If you don't see the white buildup in the valve cover, then no, you don't have a problem. I have pulled the cap off my Grand Prix with the 3.4 DOHC and it would have a little white from short drives. It was like that for years and years.

If you had water in the oil, you would see it on the valve cover (inside). I wouldn't worry yet.

J.

quote Originally posted by jaskispyder: I would say there is nothing wrong with the engine. BUT, hard to tell from photos. If you don't see the white buildup in the valve cover, then no, you don't have a problem. I have pulled the cap off my Grand Prix with the 3.4 DOHC and it would have a little white from short drives. It was like that for years and years. If you had water in the oil, you would see it on the valve cover (inside). I wouldn't worry yet. J.

Well, I can see in the engine about as well as you all can from the pics.. What you all see is what I see.. And if it looks good to you all, then it looks good to me I guess.