Date: Wed, 17 May 1995 09:46:25 -0600 (MDT)
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Stuart Hutton <hutton@poly.oscs.montana.edu>
Subject: Oil seals/leak areas: 1982 diesel engines
Hello vanagon members,
I though it would be about time to list some places that oil can leak
from the diesel engines in the vanagons. I have a continual battle
with this and am giving what may be a fairly complete list of possibilities.
Feel free to add to it as you see fit.
On the rear of the engine, there are several seals of importance.
I am going to group them into two classes: those which are relatively
easy to repair and those that aren't.
These instructions might only apply to 1982 diesel vanagon engines, I am
not sure.
(I)
1. Oil drain plug
2. dipstick connection to oil pan
3. Oil pan itself
4. rear main shaft faceplate gasket
5. rear crankshaft oil seal
6. intermediate shaft seal
7. intermediate shaft seal cover o ring
8. head gasket
9. valve cover gasket
10. Oil cooler seal
Here, a * indicates gaskets which require other gasket replacement,
TB * - timing belt removal (L) loosening
X - seal may be replaced without replacing other seals.
2 3 4 5 6 7 8 9 TB
3 X
4 * * *
5 * * *
6 * (L)
7 * (L)
8 * * *
9 X
(II)
Other places oil can leak from:
front main oil seal (flywheel side). I have not changed this (yet) so
I won't talk about it.
NOTES:
Blow-by results in oil coming out the oil filler tube. In extreme cases,
your engine will be silently committing suicide while you are unaware. The
oil will coat the entire rear of your vanagon. The oil filler cap must be
correctly installed (it is possible to not install it correctly) with the
dipstick in place. There is a small constriction at the bottom of the oil
filler tube which the dipstick fits into. This serves to hold much of the
oil blow-by in the oil pan if properly installed. However, it is not so
easy to always get the oil filler cap on properly. If your engine is
louder than normal ... it just sounds like metal clacking ... then check
your oil level. It is probably 2 quarts low. Oh, and if you suddenly hear
the sound of a muffler developing a hole on the high pressure side, stop
immediately. You may have a rod getting ready to travel through your
block.
How, you might ask, can one get the oil cap on improperly? Here is the
answer:
The oil filler tube has a small inner tube which pulls up an out thus
forming an extension which permits oil to be placed into the engine. If,
upon filling the oil, the extension is not placed correctly all the way
down the filler tube, it will pretend to form threads for the oil filler
cap. The cap will seem to screw on tightly, but about 30 minutes later,
your vanagon will have it's back end covered with oil. Learning to place
the oil cap on correctly is probably the most important step in prolonging
engine life.
I used to really torque down on it with channel locks until I noticed the
filler tube had developed a crack at its base. I now place a condom over
the dipstick tube after filling oil in order to give a slightly higher
seal pressure without blowing the main seals. (duct tape around the
dipstick will not work ... your seals will blow).
There will be other places which oil may leak from also such as the dipstick
tube (with blow-by). Also the dipstick tube may crack allowing oil to leak.
Of these seals, all of them can be replaced with the engine in place but the
front main oil seal requires removal of the transmission.
To replace the rear crankshaft seal, you should also replace the oil pan
gasket. I have found that replacement of the oil pan gasket will usually
require the retorquing of the bolts right below the crankshaft seal a few
days later. In the seal kit for the rear seal, you should have the seal
itself and also a gasket which covers the face plate.
To replace the head gasket, you will need to replace the valve cover gasket.
Other than this, the individual seals can be replaced separately. If you are
forming pools of oil on your engine between the cylinders, then you have got
to replace the head gasket. It is not difficult to do this, but you have
got to know how to do the timing belt correctly. You will also need to spend
$50 for a new set of head bolt screws from VW, and there is a special tool
which NAPA has to install/remove the head bolt screws (for about $6).
The intermediate oil shaft and the crankshaft may have marks which allow
oil to pass through even if new seals are installed. The solution for this
is to install a "speedy" bushing. I have not done this but it is one
possibility. Perhaps someone who has installed such bushings can tell how
one does this.
In order to change the head gasket, the intermediate shaft seal and the
crankshaft seal, you will need to remove the timing belt. If you have never
done this, it is pretty exacting and your engine can be destroyed if it is not
done correctly. I am not exactly sure that I can do it correctly myself,
even though I have removed it about 10 times so far. However, if good marks
are made on various pulleys, then you might be able to do it without error.
I don't recommend it if you do not have someone close who knows how to do it,
though.
Here is the method I use, ... feel free to use it, but if you destroy your
engine, don't blame me. The process is not easy to do correctly!
In any event, there are three marks which must be aligned for proper timing
belt installation. (1) on the bell housing, there is a plastic cap. Open
the plastic cap and look through while someone rotates the engine crank.
After 1 revolution, you should see a v which is cut into the clutch housing.
This v will align with a timing pointer also seen through the hole. (2) upon
removing the valve cover gasket, you will note at the back end of the cam
shaft a large cut. This cut must be aligned so that a large file can be
inserted through it ... this holds the cam in place and in practice is the
most difficult alignment to get right. VW sells a special locking tool for
doing this. (3) the fuel pump pulley has a small notch on its back side which
aligns with an arrow on the fuel pump holding bracket. Mine is off slightly,
but close. Before removing the timing belt and after aligning all the crank
shaft, be sure to note the position of all three marks. After you are sure
that you know this alignment, then you can remove your timing belt.
After installing the timing belt and applying the correct tension (too much
tension will wear out fuel pump bearings) turn over your engine with a
wrench. Listen for a clicking sound. If you hear this, you are 1 tooth
off... time to start again. If the engine will not turn completely, you
are way off ... time to start again. If the engine turns without clicking,
you are probably ok. Start your engine and listen for loud clacking. If
you hear it, stop immediately and look for errors.
One very important point: make sure to not drop any washers, screws, etc.
into the timing belt area. If you do, make sure to get them out. These
things will chew up the timing belt and destroy your engine.
Also, in order to tension the timing belt, you will need a tool which fits
into the two holes on your idler pulley with a handle. This may not be too
easy to find or make.
In principle, if you replace all these seals correctly, you ought to eliminate
oil leaks. I still am trying to eliminate my oil leaks.
Stuart Hutton
