New to this board, and is it a headgasket?

[Vanagonner]

Howdy, very nice forum.
Recently (on my stock n/a vanagon) I experienced a sudden noticeable drop in power, loss of oil pressure, drip drip drip of oil when running, and hard starting issues. It cranks over for a while creating a light grey mist out of the exhaust that smells like engine oil. Can all of things be attributed to a headgasket failure? It was running stronger than ever for a while with a new mkII pump, and I was revving it out routinely past the orange shiftmarks indicated on the speedo. once it starts, it runs but is not quite as smooth as before, and restarts easily until overnight. thanks for your opinions.

[Vanagonner]

Just to add a little more, it starts better after sitting for a week then sitting for a day. I suspect that engine oil is leaking into cyls. ?
Time for a teardown- I just want to know what to look for.
Thanks

[libbybapa]

Where is the oil dripping from?

It is very rare that the oil leaks into the cylinders.

There are several ways that a headgasket can leak. Leakage between two cylinders, leakage between a cylinder and the oil gallery, leakage between a cylinder and an oil return,leakage between a coolant passage and an oil return, leakage between a coolant passage and the exterior of the engine, leakage between an oil return and the exterior, leakage between the pressurized oil passage and the exterior and finally, leakage between a coolant passage and a cylinder. Although it does happen on occasion that more than one form of leakage will happen simultaneously, it not common. Far more often only one form of leakage occurs.

Symptoms of the various forms of leakage with regard to the VW IDI diesel engines:

Leakage between 2 cylinders will result in loss of compression in two adjacent cylinders. This is observed as prompt and extreme loss of power or even a no run situation.

Leakage between a cylinder and the oil gallery will result in significantly increased oil consumption and bluish smoke out the tailpipe due to pressurized oil being pushed into the cylinder largely on the intake stroke, but to some extent on the exhaust stroke.

Leakage between a cylinder and an oil return passage will result in vast increase in blowby. A gale of wind will blow out the oil filler when the engine is running. It will also often result in oil being blown out the dipstick hole in the oil filler on steep uphill grades. On engines equipped with a rotary vacuum pump it can result in a loss of braking ability due to the rotary pumps inability to overcome the crankcase pressure. Finally it will cause oil to leak from the crankcase everywhere possible.

Leakage between a coolant passage and the oil gallery results in a significant volume of black oil slime in the coolant. There will sometimes be some coolant that gets into the oil, but that not nearly as much due to the oil being more highly pressurized than the coolant.

Leakage between a coolant passage and an oil return will result in a significant increase of the level on the dipstick due to water entering the oil sump and the engine oil floating on top. It will form an emulsion of a cheesy like substance.

Leakage between a coolant passage and the exterior will result in coolant leaking out of the engine.

Leakage from an oil return to the exterior will result in a slight oozing leak at either the center or rear corners of the block/head seam.

Leakage from the oil gallery to the exterior will result in (an often significant) oil leak between cylinder 3 and 4 on the "pump" side of the engine.

And finally, leakage between a coolant passage and a cylinder will result in pressurization of the expansion tank when running due to the high compression of a diesel engine. Some coolant may make it into the cylinder on the intake or exhaust strokes, but usually not much by the time pressurization has caused a slew of other problems such as burst hoses, burst expansion tank, extreme over-heating. When shut down, the pressure from the cooling system can push coolant into the cylinder. If that cylinder is on the intake stroke or compression stroke, the next time the engine is cranked over it will hydro-lock if the amount of coolant in the cylinder exceeds the combustion chamber size. If the cylinder is on the power or exhaust stroke when the engine is shut down, then the coolant will be expelled out the exhaust system when the engine is cranked over.

Andrew

[Vanagonner]

Thank you Andrew- that is the most encyclopedic listing of head gasket problems I have ever seen. I hope that you have not experienced all of them personally .
My oil leak is dripping from the bottom of the block at the timing belt end of the engine, looks like it is coming from a weak main seal there. There is a lot of whitish vapor when I undo the oil filler cap. I haven't checked it with the cap off while running. It has a non-stock dipstick (from p.o.) set firmly in the filler cap, and requires unscrewing the cap to pull it out and check it. So there is no "safety valve" for excess crankcase pressure in my setup.
I also experienced the sudden loss of power you had described with the cyl-cyl breach, but the loss was not that debilitating (maybe 20%) and it still drove. I suppose that both could have happened at the same time- I was going up a longish hill in third at 45 mph at the time.
I'm going to pull the head off of it this weekend and have it checked at a shop, and make preparations to put it back together. It is a stock CS block ('82). Once I sell my caddy I WILL invest in a set of raceware or ARP head studs, and perhaps a 36mm oil pump as well.
I'd consider a metal HG, but I hesitate because It is not as simple as a good stock one. At some point, I will boost...
I have a very nice Garrett TB0326 with twin-scroll manifold I am so tempted to bolt on at the same time, but I would need to add EGT gauge and oil cooler at the same time, etc.- maybe I'll just get it back on the road first and put the turbo on last- after the other things are in. I don't want to mess this one up.

[libbybapa]

It was actually a cut and paste from a post I wrote in another thread. That's the reason that the now deleted last sentence might not have made sense. I actually think the headgasket diagnosis is premature. I'd do a compression check prior to pulling the head. Your symptoms actually sound more like a fuel issue or some busted rings. If you are going to pull the head, you might consider a rering at the same time.

Andrew

[Vanagonner]

I suspect it is bad too, and will plan on rings. I can do that with the block remaining in the vanagon? Are main and big-end bearings usually done at the same time as rings, and how do you tell if those need changing?
The last engine I re-ringed was an old BMW 2002 in the '80s. I am out of practice.
-Sage

[libbybapa]

Yes, you can re-ring with the engine in the car. It's not the best, due to cleanliness issues, but can be done. The rod and main bearings don't usually go bad. I've seen them with 200,000 miles and still within spec for new parts. On the other hand, the bearings are quite cheap. You can plastigauge them to see if they are within spec. Unfortunately, the bearings that usually fail are intermediate shaft bearings which can be checked with the engine in place, but I do not think can be changed in situ.

Andrew

[Vanagonner]

Yes, the history on the engine is good, has about 120K and was from a non-camper van. Doesn't seem to smoke blue or burn much oil- so I'll leave those factory bearings in place.
Thank you so much for sharing your expertise and best guesses here- it helps a lot!

Sage