FBIII

Anthony's suggestion is very good. My headgasket problem first surfaced for me by the milky residue in the oil separator. I'd look very closely at the thermostat housing where it attaches to the head. If its weeping it would probably run down the mating surface between the block and head. If you have had a head milled the alignment might be less than perfect or given how difficult they bolts are to get to just might need a snugging.

John Veninger

+1

hupp

Also make sure your heater valve fitting is not leaking down onto the head - maybe this is as simple as a loose hose clamp. Any fluid in the valley? Have you observed any leaks at idle in driveway?

largecar379

yep, this could also be the cause of your coolant leak.

mill the heads too much and the water crossover won't fit properly. you'd have to mill the crossover as well for a correct fit.

--Russ

Shark Attack

I have always been told this is actually normal in the strainer. the highest point of the engine, so when it heats up this is where all the steam goes and it takes very little to make a mess of the strainer. As in even just some condensation

V-Fib

I've owned the 79 for 6 years and the only time I've seen any there it was when I had a headgasket leak. But, I'm not saying it ain't possible!

marton

Or inside the cap; only normal for vehicles that do not get much use & relatively short runs.
Clean it up & go for a good run of say 100 miles, this should dry it out & then any resulting creamy effect is from coolant in the oil.
Of course a long run may not be advisable if you do have a head gasket leak.

Marton

JHowell37

Since Jon already did it, I have to say "+2" for Bars. Shortly after I got my '85 I did a compression test on the engine and came up somewhat low on one cylinder. Someone at 928 International told me that if the gauge reads 100 then it's at least partially doing its job and to not worry about it because if I pulled the engine to replace a head gasket, I'd end up rebuilding it and **** away a lot of money. So I dumped in some stop leak and have forgotten about it. 8000 miles later there are no problems.

JHowell37

+1 here as well. This is even mentioned in the service manual. I believe I had mentioned it last year when you started doing this project. This is definitely worth investigating before you disassemble your engine again.

largecar379

this is commonly missed by those who don't realize that when the heads are milled on 928 V8, the h2o crossover must be milled as well.

same goes for domestic V8's (intake manifold),

better solution is to angle mill the heads.

--Russ

mj1pate

Lots of food for thought. If its a problem in gap tollerance between the cross over and the heads, would Bars Leak be a good candidate to fix this? Its a lower pressure area than between the block and head...correct?

Mike

MPDano

Originally Posted by largecar379
yep, this could also be the cause of your coolant leak.

mill the heads too much and the water crossover won't fit properly. you'd have to mill the crossover as well for a correct fit.

--Russ

Yikes, so can you still re-surface just one head, but just make sure to also re-surface the crossover? Correct? Head gaskets for these engines are pricey, would be nice to be able to do just the affected one.

John Veninger

A slight milling of the head doesn't require the cross over milled. You can just use the thicker head gasket.

marton

Gamble a couple of bucks & try it.
What can you lose?

Marton

FlyingDog

I recommend the slimy black version over the powder. I haven't tried the copper one. I also haven't tried it in a 928, but I've used it with good results in SAABs (heater cores), Volvos (radiator, heater core, head gasket) and Fords (both head gaskets on a newly rebuilt 302).