Date: Tue, 3 Jul 2001 09:32:47 -0700
Reply-To: Tobin Copley <tobin.copley@UBC.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tobin Copley <tobin.copley@UBC.CA>
Subject: Re: [DIESEL] RE: How the heck to prime oil pump? (Vanagon D)
In-Reply-To: <B76689A0.1F3D%Cogent@GNTech.net>
Content-Type: text/plain; charset="us-ascii" ; format="flowed"
Thanks so much everyone for the comments so far. I'm going to take
another crack at it this evening after work. Since on hindsight my
earlier "update" post may have been a bit ambiguous, I'll recap. In
fact, given that I'm beginning to really be at a loss for ideas, I'm
going to be fairly detailed so that if I've left a step or test out
or made some kind of procedural error, people can spot it and correct
me. Apologies in advance for the wordiness.
1) I had the pan off and pump out to replace the connecting rod and
main bearings. That completed, I have new con rod and main bearings
in the vehicle. They were installed coated with assembly lube.
2) There was detectable wear in some of the con rod bearings. My original
oil pressure problem can likely be traced to #3 con rod bearing, which
appeared to have spun. This wear generated a noticeable amount of very
small copper flakes which accumulated in the oil pan and slightly
clogged the pickup tube screen.
3) I removed, cleaned, and reinstalled the pickup tube screen before
reassembling the engine.
4) I thoroughly cleaned the interior of the oil pan as well.
5) I am reusing my old pump and pickup tube. Rotating the pump by hand,
with the pump removed, the mechanism felt tight but smooth, near zero
backlash, and was very tight in terms of tolerance to the engine case.
A spare pump donated by a helpful listee, which looked to be completely
unworn, virtually new, felt quite a bit looser, with easily detectable
(though very slight) backlash, so I shrugged and reused my old pump.
6) I replaced the oil filter, using a new Bosch filter, pre-filling as
much as possible before installation. I added 4.0 litres of 20w50 oil
to the engine, including that added to the filter.
7) I removed the vacuum pump to give access to the oil pump shaft.
8) I removed the oil pressure sender from the head.
9) I placed a 13mm 6-point socket on a socket extension, and spun it with
an electric drill.
10) When it did not push oil out the oil pressure sender hole after 20
seconds, I removed the socket from the shaft to see if it was engaging
the dog on the shaft correctly.
11) I was greeted by a klinkity-klinkity-klunk as the socket detached from
the extension and fell down into the oil pan.
12) I drained the oil and pulled the pan again, retrieved socket.
13) I reinstalled the oil pan and exhaust system, refilled with oil.
14) Exhibiting learning behaviour, I duct-taped the socket onto the
extension.
15) After finally determining the correct direction to spin the drill (cw),
I spun the drill at high speed (corded drill) and it began to bog down
after about 30 seconds. About 5-10 seconds later, a large spurt of oil
ejected from the oil pressure sender port in the head. I shut off the
drill immediately. Total volume of oil ejected: about 1/4 cup.
16) I went to get rags to clean up the mess. Returned and cleaned up.
Time elapsed from steps 15 to 17: about 10 minutes.
17) Reset drill on oil pump shaft. Spun drill, but no oil, and no
resistance at pump. Confirmed drill was still rotating cw (it was).
Spun drill for 1 1/2 - 2 minutes at high speed. No oil, no bogging,
nothing. No indication of oil pressure.
18) Checked oil level, and to my surprise, found it reading 1 litre down.
Added 1 litre to bring it up to the "full" mark. Vehicle is sitting
level.
19) Spun drill at high speed again several times for up to 2 minutes at a
stretch. No change.
20) Confirmed the socket was still engaging properly with the shaft, and
was turning the shaft.
21) Removed the plug for the secondary oil pressure or temp. sender in the
oil cooler/filter housing. Used a pump-type oiler to inject about
1/2 cup of oil into the hole until full.
22) Leaving secondary sender hole open, spun drill again, no still no oil
pressure, and no oil ejected from even the oil filter housing sender
hole.
One thing suggested by several people is to remove the oil filter
housing and pour oil directly down to the pump from the top to try to
establish a prime. Will pouring oil into the oil sender port on the
housing do the same thing, or might the anti-flowback valve in the
filter prevent the oil from ever reaching the pump? Do I have to
circumvent the valve in the filter by removing it from the system
(that is, take the oil filter housing off)? Mike Snow indicates that
removal and reinstallation of the filter housing is quick and
straight-forward--do I have to remove the filter first? I can't see
how to get at the right-hand forward bolt otherwise. My bolts appear
to have 6mm hex (allen) heads. I count three, although there may be
one hiding under the filter.
I guess I've been holding off on pulling the filter housing because
a) it looks like a hassle, despite Mike Snow's reassurances,
b) I live on a small island and if I had to replace the gasket I'd
have to wait a couple of days for the part,
c) I really can't understand why all this would be necessary given I
got oil pumping without too much difficulty the first time around,
and I can't see that anything has changed since then.
How's this for Tobin's Crazy Theory #375: Running the drill at high
speed without prime ended up whipping up the oil into a froth within
the pump, which then permitted the pump to cavitate, thus making it
incapable of sucking up new (unaerated) oil from the sump. Perhaps I
got away with it initially, but the second run of high-speed spinning
whipped the oil left in the pump and I cavitated. Maybe if I head
out there now, after letting it sit overnight, the oil may have
settled down and I can prime again? Does this idea hold any air at
all? (heh.) Should I spin at less than max speed?
Why would I lose prime once I had it, though? Shouldn't there be a
valve somewhere to keep all the oil from flowing back to the sump
whenever the engine it shut down?
I really feel like I'm missing something.
Hmmm...
T.
At 9:51 PM -0700 7/2/01, Rachel Cogent wrote:
>Tobin:
>Before doing anything so drastic please check that the drill is turning the
>right way AGAIN. Some drills are very easy to inadvertently hit the
>direction switch. I think if you had the drill "bogged down" the system is
>OK and there are no holes in your pickup tube. You might consider tourning
>it fast by hand with the plug out.
>Rachel
>
>Entity Michael Snow spoke thus:
>
> > When I had the broken pickup tube, I was able to pump oil for a few seconds
> > when the pump was primed through the filter mount hole. As soon
>as that oil
> > was expelled, pressure went back to zero. If you are absolutely sure that
> > there is enough oil in the pan and you are turning the pump the right
> > direction, this is probably the time to pull the pan. Remove the oil pump
> > and pickup tube and examine them closely. My pickup tube broke on the top
> > of the casting by the pressure relief valve, inside the pump. This area is
> > not visible without removing the pickup tube from the pump. The casting is
> > very thin at this point, about 1.5mm. I sincerely hope that this is NOT
> > your problem.
> >
> > Mike Snow
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Tobin Copley Bowen Island, BC, Canada 49deg 23'N-123deg 19'W
'82 Westfalia 1.6L NA diesel ("Stinky")
'97 son Russell =============
'99 daughter Margaret /_| |_L| |__|:| clatter
SPEED KILLS! {. .| clatter!
Drive a Vanagon diesel ~-()-==----()-~
| 
