Date: Sat, 5 May 2007 22:13:02 -0700
Reply-To: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
Subject: oil pressure
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Dear VW community,
I know this is a well-discussed problem and I read lots of threads and
goolged even more, still I would like to get a few more insights as I
don't know where the problem might be.
I am talking about my 1987 Vanagon, 2.1l waterboxer, Digifant, automatic
transmission.
I had a bad oil tube to the third main bearing, and ignored a bit too
long (10km on and off ) the oil warning light/buzzer. OK that blew one
the bearing. I took the engine out, completely took it apart at took the
parts to the machine shop so that they could machine the crank, the
heads, the cylinders, the cam and cleaned all junk out of the case. I
got a new gasket set, new oil pump, certainly new bearings, new drive
shafts/gears (distributor and cam). OK during spare times in the winter
a good friend and me built it together. Great! We brought it back into
the car, fired it up and it ran right away!!
Now first we experienced low oil pressure if the engine warmed up. It
was to overcome by slightly tipping on the accelerator but OK thats not
good. So i changed the relief valve spring which I should have done in
first place, changed the 0.9bar switch and also changed to 20W50 as I
first had 10W30 synthec. Certainly I also changed the oil filter right
away (Mahle, black).
After restarting, the temperature display would not move. After
rebleeding and no change, i changed the sender, and it worked. OK it did
work in first place when i first experienced the bad oil pressure and
now just bad lick I guess. Well anyway this problem is fixed. But after
warming it up I again get the pow oil pressure buzzer. No blinking
though while idleing or slightly lower rpm, do the 0.3bar sender does
not indicate, but the 0.9bar kicks in after warming it up and going
above 2600!! Hm Why 2600 and not 2000? Do I have the right oil pressure
at 2000 and then it drops? Hm very weired. OK I unplugged the 0.9bar
sender at the cable where it connects to the wiring from the harness and
watched when the buzzer comes on now just to see if the electronics
work. OK same thing again 2600 it comes on.
OK something in the electronics does not work exactly as it is supposed
to do, but anyway the low oil pressure is for real
, I guess. What the hack is going on? A problem with the new oil pump? a
missing gasket? Not that I know, we added the flat gasket between case
and pump, and the other flat gasket with additional holes between cover
(not new though .. will change when I have to open it again) and pump.
Now after inspection, I do not see any material between case and pump
... was there a groove for this gasket? i don't know any more. But I do
see the flat gasket between cover and pump. Hm now after thinking a bot
more, is this gasket OK to have here? I know some explosion drawings
show it, some not. Should the gears touch the cover to not let oil
bypass them? With this gasket of ~1mm certainly oil can bypass the gears.
Or, did the shop recommended the wrong set of main bearings -- they
said, the original sized ones will fit, and i just do not have enough
back pressure to maintain 2/3 bar above 2000rpms? (Please not as I do
not really feel to open everything until the last screw again)
I know that without any real oil pressure gauge nobody can help right
now, so i will install a mechanical gauge and see what the real pressure
says. however, as the 0.9bar sender is new (Hey what a pain to install
with the engine in the car), I am quite confident, that the problem is
insight (unfortunately).
If the main bearings are a little bit too large, would the heavy duty
oil pump overcome this problem? I guess it depends on how far off i am
with my pressure, well just below 0.9bar I guess, as a small tip on the
accelerator shuts the buzzer off. But it should have anyways between 2
and 3 bar, and not somewhere around 0.9 bar.
I would greatly appreciate if anyone could help me with this problem or
experienced the same error and found a solution. I do not see any oil
drop. However there is a little bit near the oil pump, but not a lot,
even after running it for 20/30 minutes (I did not longer terms, as I am
afraid to damage something .. even if the buzzer was not on)
Why does the switch to the 0.9bar sender comes at 2600 rpms and not at
2000? The green wires are connected to the ignition coil. There are two
open yellow connectors near the electrical ignition system box, which
are not connected, and I think they were not when I took the engine off,
but I am not sure. Do i have to connect them? I could not find from the
Bentley for whet they are there.
I hope that was not too long.
Please let know what you think. I will keep you posted, what the oil
pressure gauge says, once I have found one and the right M11x1 adapter
to the 0.3bar thread.
Thanks
Thomas
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