Crimsonnaire

iTrader: (1)

Would anyone happen to know if the presence of engine oil soot on the coolant reservior stick is necessarily an indication of a leak from the gasket? Or rather, is there any other way oil could get into the coolant reservior besides a gasket leak?

waldershrek

iTrader: (1)

If you are talking about the overflow jug for the coolant then no I have no idea. I have never heard of that happening.

wssix99

iTrader: (5)

Yes - Its probably not oil - its most likely power steering fluid. The fluid forms gooey clumps on the coolant resovior stick.

The SS and WS6 have power steering cooler, which is in-line with the cooling system. (Between the radiator and the engine.) I assume corrosion in the inside of the cooler allows the high pressure power steering fluid to enter the coolant system.

I had this happen to me when my car was new and the dealer fixed it under warranty. I got a new cooler and convinced them to power flush the system twice and that seemed to clear out all of the residue from the system. Been driving 60K since and had no other issues. (When it happened to me, both the dealer and I were stumpped. The dealer had to put in a call to GM engineers. - Its a very odd thing.)

If you want to post a picture of what your dipstick looks like, I can confirm if it matches what I saw with my problem.

bluehawk2

iTrader: (74)

Sometimes the dexcool will form a milk film like that. Mine started leaving a milky film in the overflow tank. i flushed it out really well and haven't had any probs with it since.

Crimsonnaire

iTrader: (1)

That's a good idea! I'll take a picture tomorrow and post it up.

The guy at Meineke told me that it was engine oil, judging from the orangy-yellow color. I had stopped by a Pontiac dealership today, and when asked, I was told that engine oil could get into the coolant reservior when there's an internal leak in the gasket. Up until I read all of your posts, I was convinced that it was engine oil, but now I have some hope that it's not as severe. Replacing a gasket at Pontiac's could cost $600 + labor, and over $2k for a head gasket. Yikes!

01WS6/tamu

iTrader: (37)

Are you an A-4 or m6? The power steering cooler is external and does not tie into or through the engine cooling system so you can rule that one out. However if you are an a-4 the trans cooler in the radiator my be seeping. But the coolant would look like a strawberry milkshake and not yellow like you are describing. Yellow sure sounds like engine oil and the coolant are mixing at some point.

Crimsonnaire

iTrader: (1)

Mine is a 5.7L V8 M6.

If the oil and coolant are mixing, what would be the first thing that would go wrong with the engine if not attended to?

blubyou02

iTrader: (1)

have you checked to see if theres water in the oil or on the dipstick

Crimsonnaire

iTrader: (1)

I did notice a brownish liquid on the dipstick, but it's the only separate substance from the yellow soot, so I assumed that's the coolant fluid. All I know about the coolant is that it's the 'green' type. The guy explained that GM engines get along fine with it.

wssix99

iTrader: (5)

I wish my cooler was external! (Maybe GM got smart is subsequent years?) -> Here's the power steering cooler on my 1999 WS6 (M6) - part number 10417037. The high pressure power steering passage coils around the coolant hose like a python. (The factory manuals list the part as being associated with the 5.7L, but I recall hearing somewhere that the cooler was only installed on the SS and WS6 cars.)

Once power steering fluid mixes with the stock coolant, its unrecognizable. It looks oily but has the consistency of ectoplasmic snot. The substance is so sticky that I couldn't get it off and also had to replace the coolant dipstick & cap.

BTW - Another tell tale sign of a power steering cooler problem is a very low power steering reservoir. When mine went, I lost power steering fluid at a very high rate.

Crimsonnaire

iTrader: (1)

My TA is a 1999 also! What color was the goo?

So the power steering fluid dripped into the coolant reservior from the coils surrouding the reservior??

wssix99

iTrader: (5)

The wet goo was the color of oil and I recall some yellowish dry crust all over the stick. It was the dry stuff I couldn't get off the plastic dipstick.

I didn't get a chance to cut open the old cooler and see how it works/leaked, but I assume the power steering line coils around the coolant tube inside the cooling unit. The leak occurred at some location in the cooler where the two fluids flow next to each other. Since the power steering fluid is at such a greater pressure, I only had migration in to the coolant system and not vice-versa.

How is your power steering fluid level? (If its still normal, your problem is probably not a P/S cooler leak.)

Crimsonnaire

iTrader: (1)

I checked the power steering reservior first thing today, and the level is perfectly normal. It's been over a month since the PS fluid was replenished, and the cap stick showed a perfect cold level right on the line. This pretty much concludes the substance in the coolant to be engine oil.

I will get this taken care of at Meineke.

Thank you all for chiming in.

wssix99

iTrader: (5)

Getting in to head gasket issues can be expensive. If you are sure its not loosing PS fluid, then that makes a leaking cooler less likely.

If there's chocolate in your peanut butter, there's definitely peanut butter in your chocolate... If you aren't having any immediate performance problems, I'd suggest getting an oil analysis done. (I believe there are companies that will do it for $25 or so.) If you have a head problem and an oil to coolant exchange, they will be able to detect coolant/salts in your oil.

Not sure what a mechanic can do to confirm an oil to coolant leak or how much it would cost but an oil analysis should be an inexpensive way to put you on the right corrective path.

Crimsonnaire

iTrader: (1)

Thank you very much for the suggestion. This is also what the guy at Meineke recommended--to just wait a while and see if the mixture changes in any way, which I presume is the fluid analysis you speak of. As for performance, it's great.

From what I understand, the oil could only be coming from either the intake manifold or the head gasket... or both. If the head gasket is blown, I was told that the temperature gauge would be at a noticeably higher level when driving on the highway. And yes, the cost of replacing either is considerable--$700-$1600. But if this is indeed the problem, I would like to have it taken care of right away to avoid any collateral damage to any of the other components.

As for the coolant mixing in with the enigne oil, it depends on where the leak is taking place. I don't remember the exact words, but I got the impression that the head gasket leak will allow direct contact of the fluids, whereas the intake manifold will usually allow only the oil to drip into the coolant.

It's scary to think that you could have an oil leak and not even know it. My oil stick showed a consistent full level, but some oil leaks are so gradual that you can't even see an indication from the stick until after a long time. This is in addition to not getting any drops on the ground, making you think that everything is A-OK.

wssix99

iTrader: (5)

An interesting thing with our coolant system is the dipstick. The ladder-style stamping in the plastic will tend to gather substances. (Its engineered to use the coolant's surface tension to create "bubbles" across the rungs so you can see what the level is.)

So, I'd imagine that even a small amount of a foreign substance in the overflow tank would tend to gravitate to and stick to the dipstick.

5301113

iTrader: (18)

Same thing here. fix the power steering cooler and flush your coolant and it will fix the problem