I hope its an external leak. I checked my oil with the deep stick and did not see any choclate milk on it. but when I drained the oil ther was about a gallon of coolant in it. also I noticed that the oil level has increased alot when looking at the deep stick.
hopefully its noting, but did you do any work on the engine before driving ?

 

As is a leak in the radiator side tank for the transmission cooler. You might want to check your A/T fluid level.

Probably a reasonably safe bet.

 

Luc--

The low percentage of coolant might be an issue for you, depending on how the car is stored in the winter, and more importantly how cold it was during that time. I hear it can get a little chilly in Montreal in the winter. A little ice formed in the radiator or coolant reservoir, the places most likely to freeze first, could easily fracture the plastic parts there. The cracks may show up only when pressure is applied. Try borrowing a cooling system pressure checker from your local parts supplier, and add 15PSI or so (1 bar) to the full cooling system while cold, and see where the water is running out. The plastic tanks on the radiator and the coolant reservoir are pretty well aged by now, after 25+ years. A fracture on either or both should not suprise you at all. But don't limit your leak-looking to just those two places. A fractured heater control valve will spray hot coolant on the MAF and throttle body, causing water to appear via those oil vent hoses. For instance. Plenty of places to look for telltales of leakage.

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I'm somewhat confused by your apparent symptoms. The oil filler neck appears to be contaminated with coolant, yet the oil in the sump shows none. If you are looking at the dipstick after the car has been sitting for a while, it's possible the water contamination in the oil has dropped under the oil layer. Time to carefully pull the oil drain plug and see what comes out first. If it isn't water, you are guided away from an internal leakage problem.


Start off with the cooling system pressure test and see if that system holds pressure. Then a compression test to see if there's a head gasket problem or something similar. However, if there's any sign of water in the sump under the oil, be sure to put fresh oil and filter in before cranking for the compression test or starting the engine.

 

Bob, I usually agree with what you say or at least the parts I know any thing about, but I really think pressure testing to 15 PSI on a old radiator may be a bit much, if it is not leaking now, it might soon be, I would start with no more than ten.

Just my $.02

For what it is worth we always go straight to the block tester any time we suspect a blown head gasket.
I just found one on fleabay for ten bucks.

I use the BMW type that have 2 chambers, but they do work.

 

Luc................check all the external hoses etc associated with the coolant.

I'd start with the obvious drains on the rad and block, the main hoses, the smaller hoses to the hot water valve, the heat exchanger and return hose. The t.stat housing and the water bridge not forgetting the bolts at the back off the engine that go into the water jacket.

If that all fails then perhaps there is an internal failure and would go with a pressure test that Bob states slowly increasing pressure.

 

This is what I found. I looks like the coolant is leaking on the driver side manifold.

And the head has visible work done on it

 

Dr Bob,

The car is always stored in my heated garage. I never use it between November and April. Never use it below freezing.

Thanks for your help.

 

Exactly what are we looking at in the second picture?
It looks like something has been welded.

 

Thanks Greg--

I'm with you on the block tester if one is available, but I was headed for stuff that can be done easily, DIY by an owner with unknown-to-me resources, etc. The 15PSI/1 Bar pressure is the relief pressure on the factory reservoir cap. I guess if the system won't (didn't) hold to the cap rating now's a good time to find out. You can sneak up slowly on the 15 if you want, or maybe test the cap first and limit your testing of the radiator to that pressure.

I also promote the idea that as much testing as possible should be done without firing the engine again, at least until clean oil can go in and a reasonable number of leakage opportunities are identified and/or eliminated.

Folks following along at home should know that I'm very much a lazy armchair diagnostician. I did in fact watch a guy work on a Fita transmission, and base all my prognostications on that experience early in life. Since even before then I've purchased lots of tools, carried dthem around in lots of nice and more not-so-nice cars. I have those tool stockpiled at home in red cabinets to impress visitors, but seldom actually get them dirty anymore. Blown 87 does work with the tools every day, hopefully putting food on the table and more. He has to be good at this stuff, better than a grizzled old fart like me has to be. I'm not current on a lot of the technology available, like block testers. Used to use a simple combustion vapor and chemical indicator system on coolant to see if there's gas passing to the cooling system. I bet things are a bit better now.

 

I will start tomorrow by draining the oil and see if there is water. Then the cooling pressure test.

Too bad for tomorrow DE at Mont Tremblant

 

Kinda looks like where someone pryed trying to get the cam cover off? I'm still not sure we are looking at coolant leaking from there though.

 

You are right. It is the driver side cylinder head.

 

The only place that I can see coolant leakage (white residue) is on the driver side exhaust manifold. No white residue on the right side. The weld is on the driver side cylinder head.

 

Thanks Bob, on the block tester we are talking about the same thing, just a simple devise the draws the gasses off the top of the cooling system through a liquid that changes color in the presence of combustion chamber gasses.

I would also take the plugs out and spin the motor after doing the pressure tests, for a couple of reasons, to keep it from hydrolocking and if there is a leak into a chamber you are going to know it quick.

I wanted to add one thing, I do work on cars for a living, but I come here to the experts for advise on the 928's.
Guys like Bob have forgotten more about 928's than most pro mechanics will ever know, we just do not see enough of them.

 

I am going to go out on a limb here and say the leak is at the block off plate at the rear of the head on the drivers side.