Author Topic: Headgasket, rings or other? (Read 2882 times)

burn_your_money · « **on:** April 30, 2008, 12:09:10 pm »

1994 AAZ

When the engine is cold there is very little smoke coming out of the oil filler, when it is warm it billows out.

At idle with the engine warm there isn't much smoke but when you rev it up there are plooms of blue smoke.

compression tests on warm engine:
#1) 350
#2) 420
#3) 460
#4) 460

After adding 1/2 teaspoon of oil to #1 it went up to 400.

Is it possible that the headgasket failed and is leaking oil into #1 and #2 or is it pretty much a gaurantee that it is the rings?

if it is the rings, can we hone and put new rings in just that one cylinder? Money is of a great concern so we need to do this as cheaply as possible even if it means doing it again in a year or two.

zukgod1 · « **Reply #1 on:** April 30, 2008, 12:33:06 pm »

I don't think you have a HG leaking oil or your comp test would have been higher.

Obviously the rings are worn if you are getting blue smoke out the oil filler hole. The compression is blowing past the rings filling the crankcase with exhaust.

Could be a easy re-ring deal and off to the races ya go. End up with a new HG at that point to eliminate that as a possibility.

burnt_servo · « **Reply #2 on:** April 30, 2008, 12:37:36 pm »

i've seen something similar on gas engines with aluminum heads and thin cylinder walls ( ie chevy 400 small block ) .

as the head heated up it expanded more than the iron block putting more tension on the head bolts , which caused more distortion of the cylinder wall , causing loss of compression , blowby and oil comsumption when it was hot .

what over size are your pistons ?

if it is cylinder distortion , using a torque plate to have it bored oversize and using head studs that go all the way to the bottom of the threads of the block is the way to go .

but that said , i've never seen this in a vw ..... but anything is possible .

Possum79 · « **Reply #3 on:** April 30, 2008, 12:45:21 pm »

I was wondering myself about if you can do it to one cylinder.

Bentley says if oil raises the psi then rings are bad. But you've probably already read that. :lol:

Vincent Waldon · « **Reply #4 on:** April 30, 2008, 01:01:38 pm »

Hmmm... interesting !

Some thoughts:

- any other signs of a headgasket issue around #1 ?? Seepage ?? Water in oil anywhere ?? Pressure in the coolant system ??

- sure the rings may be a bit off in #1... but "plumbs of blue smoke" sounds like more than just worn rings on one cylinder. Any blue smoke on deceleration (meaning valve seals, which are cheap and dead easy to do in situ on a diesel) ?

- what's your oil consumption like ? what's your oil pressure like ?? Might have a gallery leak once the oil thins up ?? Running a thick oil ??

zukgod1 · « **Reply #5 on:** April 30, 2008, 01:50:28 pm »

The way he worded that Vince the smoke was comming out the valve cover where ya fill it with oul not the tail pipe..

BlackTieTD · « **Reply #6 on:** April 30, 2008, 03:13:23 pm »

there is smoke coming out of the tailpipe, as well as the oil fill and dip stick locations. oil is not being forced out. will try to get a video.

pressure in coolant system doesn't seem to be an issue. there are some black flecks in the coolant but this is an engine swap so that might not be directly related to the problems we are having now.

oil consumption is high. a litre a 1/2 tank is a rough estimate. it does have rotella 0w40 synthetic in it which likely makes it smoke more and use more oil. we have been adding in compatible 10w30 dino oil as we top up. no oil pressure gauge. we have a VDO one here we will try to rig up if we have the right sender.

the car hasn't been driven regularily in a while so some of the smoke could be from sitting, however, when the car was last driven it seemed to smoke just as much and use just as much oil (winter driving).

dillenger1 · « **Reply #7 on:** April 30, 2008, 06:55:01 pm »

I did not find valve seals easy to do on my hyd. head?I had a home made spring compressor with the VW seal pliers and it took me 3 hours to get the retainers seated properly.

Quote from: "Vincent Waldon"

Hmmm... interesting !

Some thoughts:

- any other signs of a headgasket issue around #1 ?? Seepage ?? Water in oil anywhere ?? Pressure in the coolant system ??

- sure the rings may be a bit off in #1... but "plumbs of blue smoke" sounds like more than just worn rings on one cylinder. Any blue smoke on deceleration (meaning valve seals, which are cheap and dead easy to do in situ on a diesel) ?

- what's your oil consumption like ? what's your oil pressure like ?? Might have a gallery leak once the oil thins up ?? Running a thick oil ??

theman53 · « **Reply #8 on:** May 07, 2008, 01:08:05 am »

I was having a similar problem and I half fixed it. I put on one of those baffles that cover the cam and went from a synthetic to rotella t 15-40 and my oil comsuption decreased considerably. If you don't have a baffle then I don't think it would hurt. I have mech. head, but if you don't put one of those on a hyd. head then you'll have some serious oil eating going on

. I am with you on the rings though, I would guess that or some serious valve trouble. I didn't have it comming out the dipstick though :shock:

mtnsammy · « **Reply #9 on:** May 27, 2008, 09:44:42 pm »

My last rebuild left me with high crankcase pressure too. It blows out top and bottom of dipstick as well from the breather. My turbo is set at 15 max boost. Compression is equal across at 440.

I have been thinking the drain from the turbo was plugged but I really have no idea. Turbo does sound louder than it used to.

mk2diesel · « **Reply #10 on:** May 29, 2008, 09:55:06 pm »

try running straight 40 or 50 dino oil first ... (thicker oil so less blow by ..) a la wallsmart

rings are usually sold in sets for 4 pistons .....

but sounds like the rings are on the way out, so may as well change them all at this point.