924Board.org

[Khal]

Strange goings on...

My car has had a coolant leak for a while. It's nothing too serious but every now and then I have to top it up and I'll see a dribble on the floor on startup -I figure it's pooling in a recess near the top of the engine somewhere and then dribbling down when the engine cranks (obviously, it shakes a bit when it's starting).

Anyways, I went to top up the oil last week and when I pulled the dipstick out, it had coffee-like liquid around the top, just like when you mix oil and coolant... *groan*

The strangeness? Well, my engine starts and runs fine. Really nice in fact. Doesn't get hot and doesn't seem to lack any power. Nice and smooth and free revving (it's got a lumpy -but regular -idle but it's always had that and I suspect it's got a non-stock cam ). And the oil itself seems to be a nice colour, clear and syrupy. The coffee-like stuff is just around the top of the dipstick.

So, would I be anywhere near the mark in thinking I've got a (very?) minor crack in the head gasket somewhere that's letting a small amount of coolant mix with the oil but isn't having a major effect on the engine? Yet...

There doesn't seem to be any oil in the coolant. It always looks nice and greenish-clear.

Your thoughts, Gurus?
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'80 924 Turbo

[endwrench]

I'd say your only saving grace here is the external leak. This does point to a general head gasket failure. If not I would say you may have a cracked head like the on in this picture:


Thanks to ImageShack for Free Image Hosting

Todd

[Khal]

[Kenodog]

C'mon,pull yourself together man !

Probably just a headgasket,6 hours labour and a $50 gasket.Comes with some piece of mind in that you can see stuff you normally wouldn't if it were all together.Good time to replace the heater core hoses,check the WUR,tighten the wastegate lines etc.
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[Tigger937]

Check the plastic coolant overflow bottle for excess pressure. When the engine is fully warm, does the bottle expand like a balloon as noted by the cap area bloating outwards? This happened to me once and the head gasket was fine, but the head mating surface was warped between the #2 & #3 cylinders. It wasn't much, less than .010". Anyway, that was enough to allow leakage from the cylinder into the cooling jacket, thereby pressurizing the entire cooling system. Also, the exhaust valve in the #3 cylinder was discolored from the antifreeze (lighter shade of brown compared to the others) indicating coolant was getting into the combustion chamber. The fix was to have the head mating surface re-machine by shaving off .010" or so. Since the head was off, I had a valve job done too along with other maintenance items for the parts that were now easy to access.

A few things to try first:
First, I'd try changing the oil and see if the milkyness returns. Second, try pressurizing the cooling system with a pressure tester to 20psi or so and check for leaks. Third, do a compression test and look for low pressure in one or more of the cylinders. Fourth, try re-torqueing the head bolts to proper specifications before pulling the head off. Good luck!
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"

[numbbers]

Well, before you go take out a loan, do everything Trigger says, and crawl underneath and find out where that leak is coming from. It may just be from the waterpump. And the coffee looking liquid may be from high humidity, after all, it is winter down there. If you have coolant getting into your oil, it will be light brown and foamy, like a chocolate shake. Good luck.
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1980 924 Turbo

[Lizard]

Khal, dont start your car with that milkshake in there!, you will cause damage to the bearings, it is more likely just a headgasket failure unless you have overheated your car and then you are more likely to run the risk of a head cracking.

I would agree with the compression test, although sometimes that does NOT isolate the issue, a leakdown tester however WOULD find exactly where the issue is,

I personally would NOT bother replacing the oil, but finding out which cyl has poped and go from there, or just dive in,
as per the water leaking on the floor, that will either be a slight leak out of a rotten or punctured hose, or more likely a waterpump seal gone, but do you happen to notice if the leak is at the front of the engine or the rear?

also if you are just going to have this done by a shop but can wait a month you could fly me out and I would bring a headgasket and waterpump with me as they will be cheaper, you would just have to pay for the flight

good luck either way
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3 928s,

[Khal]

Well, the flight might be cheaper than getting the mechanic to do it...

Fair enough, it's probably not a good idea to run the car like it is. But whatever it is, it's gotta be pretty minor (for now) 'cause as I've mentioned, she starts first turn of the key and purrs like a kitten.

She hasn't overheated, according to the temp. gauge.

I've got a compression tester so I can do that. I don't have a cooling system pressurizer or a leakdown tester (what's that?).

Again, the oil is nice and clear, it had some coffee-like stuff near the top of the dipstick.

The coolant leak is from the rear, drivers-side (exhaust/passenger side for the wrong-handed of us... ), so I guess it's not the water pump. I could see a few drops against the inside of the engine bay but I just can't quite see where it's coming from...
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'80 924 Turbo

[kaffine]

You could send in an oil sample to check for coolant in the oil. They can detect coolant well before you can tell by looking at it. I'm don't know of any in Austraila. If you can't find one in the yellow pages see if you have a Cat Equipment dealer or other large truck or equipment dealer they should be able to do it or tell you who can.
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80 924
80 931

The best desciption of an atom boils down to something unknown is doing we don't know what.
Sir Arthur Eddington

[Khal]

[Tigger937]

Khal, there are many coolant hoses between the rear of the engine and the firewall...............I am currently working in that area on my car. There's a coolant flange underneath the distributor mounting flange.

http://pg.photos.yahoo.com/ph/tigger0937/detail?.dir=c3e9&.dnm=6493.jpg

It connects to the heater core and also to a hose containing temperature switches. It gets bloody hot back there with heat from the exhaust manifold and turbo. Also, the wastegate sits just underneath too. The heater control valve is back there too, just under the coil (the coil is easy to remove, just 2 nuts). If those hoses are original, they are probably very soft and cracked. Also, the heater core could possibly leak there too...................have you noticed any coolant inside the car near the heater??? Again, a pressure tester could reveal much............you might check with your local auto parts store, maybe they have one you could borrow.

[Khal]

[Tigger937]

That could explain a lot. First, if you don't have snow, that's NOT winter!!!
Anyway, with the 5°C temps at night and the fact you don't drive it much, my guess is you just have a buildup of condensation, especially with those 25°C days. Under those conditions, metal sweats a lot. This is why auto and oil manufacturers specify drain intervals based on mileage AND time. Add a can of engine flush, idle for 5 minutes per the instructions on the can, change the oil and I think you'll be fine. One other thing, when you change your oil, make sure you do it when it's hot. That way, you get most of the condensation out too.

In regards to the coolant leak, have you had any work performed at the rear of the engine just prior to the time when you started noticing it? Perhaps a hose clamp or bolt was not tightened enough (or worse yet, stripped) or maybe a gasket was not replaced when it should have been.

BTW, is a 932 a 931 RHD? Just curious.
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"

[Khal]

[numbbers]

Well, I still think you may be OK on that head gasket. The last leak I had at the rear of the head turned out to be the "S" shaped heater hose. Get a bright flashlight, and get your head way back under the hood, and see if you can find the leak. If your leak is from anywhere other than the head itself, you will know that your headgasket is OK.
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1980 924 Turbo