Oil in coolant: headgasket or block liner o-ring?

[salamandrrr]

Hello Alfa owners,

I wrote a long post recently about my 1984 GTV6 blown headgasket with background etc. But I just heard from a mechanic that 90% of the time when oil is in coolant, it is that o-ring that seals the 90psi from the nearby water jacket(s), and it is located in each head to block pairing. I was a little confused, but I guess the bikini vs. one piece difference just encompasses those 3 aluminum rings that go around the pistons. So the one piece head gasket comes with rubber o-rings for the 90 psi jacket that supplies oil to the head.

According to this guy, about 10% of the time, it is the o-ring at the bottom of the liner or insert, in the block, that seals oil from coolant that goes bad. And when you take the heads off, it may not be very obvious what the failure mechanism is. This mechanic did one of these block o-ring jobs but cannot remember how he diagnosed the problem or if he did the job twice. Has anybody come across this problem, and have any good diagnostic tests or advice on how to distinguish the two from each other? I'd rather not do this job twice.

Thanks in advance,
Sal in Norcal

[salamandrrr]

BTW, I say I have oil in my coolant, because I saw a white milkshake frothy coolant. Continental Motors found water in my cylinders. They couldn't verify if there was oil in my coolant, because it all leaked out due to a loose hose clamp. They said headgasket is the problem for sure.

Wondering if I should pull the sleeve liners out and look at those o-rings at the bottom in the block just to be thorough and safe? Whattya think?

Thanks in advance,
Sal in Norcal

[alfari]

Hi Sal,

Sorry if I'm missing something between this and the other thread, but why not try torque the head bolts (since you stated it wasn't done post purchase), refill your system, and check to see if it reappears.

Is it because it has developed since you purchased, or is it because water in the cylinder indicates this wouldn't fix it? Sorry, engine theory newbie trying to help and learn at the same time

[ToonRboy]

Sal,

You bought a 116 car that sat for 10 years? Brave. Got any pictures of it?
Also, you say Continental Motors found water in the cylinders, which would support the headgasket point. "O"-rings under the cylinder sleeves are unlikely, but possible if when removing the heads (to replace the head gaskets 15yrs ago ) they were damaged somehow.

Another thing you probably aren't aware of, and could be of importance depending on where you live, is internal corrosion. The alloy that the Alfa block and head are made of could actually rust through or crack. Especially if the coolant wasn't drained prior to the "Rip-Van-Winkle" and it slept somewhere that freezes. Coolant that sits that long will lose it's ability to withstand freezing temperatures. -Water expands when it freezes.

Anyhow, I would say: "When in doubt, there is no doubt". That vehicle would need it's fuel system and coolant system flushed. Wouldn't surprise me if it needed one or two injectors as fuel turns to varnish over time. Have the radiator pressure tested after the flush, replace the cam belt, water pump and de-tensioner along with the head gaskets and if any of the sleeves can be rocked or pulled-out by hand, replace the "O"-rings underneath. After it's all back together, replace the idle speed "o"-ring, plugs/cap/rotor and throw some new accessory belts on there as well. Have Continental inspect the brakes, suspension, steering boots, CV boots, ball joints, bushings, and guibos. Replace the trans and diff fluid, and grease the clutch throw-out fork at the pivot ball. Hell, may as well flush the brake and clutch hydraulics too. That's all I can think of right now but I imagine there will be other things to attend to later - you know, the 'lectrical stuff...

Good luck with it, and hopefully, have some fun!

[salamandrrr]

Hello Spencer,

I don't have experience with just doing a torque down of head fasteners and crossing your fingers with a case like this . Maybe some other people could weigh in here...

But my inclination is that I'm pretty screwed when I find oil in my coolant and water in my cylinders. This means there are multiple new paths where liquids are going where they aren't supposed to go. To further complicate matters, the leak down test showed that I have 50% leakage out through my tailpipe, meaning my exhaust valves are not sealing properly. One theory that ToonRBoy mentioned is that maybe my head(s) are cracked, and that would explain everything.

Anyways, I have so much momentum going right now to tear into this motor this weekend....that unless someone swoops in with last minute info and advice on a better solution, I'm putting on my shade tree mechanic outfit tomorrow. If I do, I should have some more info and pictures soon.

Thanks,
Sal

[MR2 Zig]

Gaskets, once leaky, never stop leaking, unless they are teflon, and then only sometimes do they stop leaking. We don't have teflon gaskets on Alfas, so replacement is in order.

I'd replace the clyinder base "O" rings also, they probably will not seal after having the heads removed (age thing here...I'd replace these o-rings if engine had run for a year).

Your spark plug well seals and valve cover gaskets are the likely sources of upper engine external oil leakage.

Your upper and lower oilpan gaskets are likely sources of lower external leakage.

As previously suggested, replace your cam, distributor, and crankshaft (front) seals. If these are bad you WILL get oil on your new timing belt with, not immediate, but catastrophic results (bent valves). The oil on the belt doesn't necessarily cause slipping, but it does cause the rubber to go bad and then the teeth on the belt shear off.

hth
Scott