[Vwdiesel] Nicks oil pressure problem
gary
gbangs at cfl.rr.com
Thu Sep 23 13:15:56 EDT 2004
At 2000 miles, the rings haven't broken in yet. A lot of blow-by would
be a good indicator of this. And no, there is no PCV valve like a
gasser.
When you rebuilt the engine, did the intermediate shaft bearings get
replaced as well? These are often overlooked and will definitely cause
low oil pressure.
The spec is 28# at 2000 rpm. At 55, you are doing what? 2400? Your
pressure is definitely too low.
If your turbo seals were so bad as to cause this low of oil pressure,
you would have runaway, or have oil literally flowing out your exhaust.
Are you running the engine hard? When breaking in rings the trick is to
run the hell out of it. The more cylinder pressure the better.
The ring issue will most likely resolve. The low oil pressure however,
will not get any better.
-Gary
On Thu, 2004-09-23 at 12:10, mikitka wrote:
> Interesting thing I just found out. I actually hooked up my mechanical oil
> pressure gage at the oil filter tap, On start up it went up to 80psi, but
> went down to 8psi at idle at operating temp. Now if I drive it at 55mph in
> 5th gear it is at 20psi. Sitting at idle and getting 8psi, if I run the
> throttle up to max rpm, (remember I don't have a tach and going by ear) it
> runs up to 50psi at operating temp. This is running 15w-40 oil. Remember the
> engine just was rebuilt 2K miles ago, all new bearings, oil pump, pistons,
> and bored .020 over. My question is how can this be running and getting oil
> all over the place in the head and up around my cam with such little oil
> pressure? The thing runs great. I do have a consumption problem though. Not
> sure what it is but I go through a quart of oil every 400 to 500 miles. The
> tube to the valve cover breather is soaked with oil. I checked the breather
> and you can blow air through it from the valve cover side and back through
> the intake tube side. It doesn't work like a normal PCV valve like I thought
> it would. The next thing for me to check is compression. Can that really
> tell me anything? I can have great compression but if the oil rings are
> trashed for some reason would that show on a compression test? I also am
> looking at the turbo. Could bad seals in that cause low pressure if it is
> eating oil from there?
>
>
>
> Just another day with the oil mystery machine.
>
>
>
>
>
>
>
> -----Original Message-----
> From: Mark Shepherd [mailto:mark at shepher.fsnet.co.uk]
> Sent: Monday, August 30, 2004 6:24 AM
> To: mikitka
> Subject: Re: [Vwdiesel] Nicks Pressure drop
>
>
>
>
>
>
>
>
>
> > Ok this is all new to me, do I reply to the
>
> person or to vwdiesel at vwfans.com
>
> > ?
>
> >
>
> As I read the site daily I personaly think it
>
> benefits others to read the progress from symptoms
>
> to actuality; although in my case I'm probably
>
> filling up the inboxes with 'gibberish'..(Just
>
> trying to put a little colour into diesel (unless
>
> you're already using red diesel :o) But you are
>
> welcome to do either...
>
>
>
> With regards your problem some of my advice
>
> rodding the head oilways may not be appropriate
>
> (I've been looking at an old Bedford CF) Air
>
> pressure may help. I think the best check is to
>
> verify that the cam area IS being starved by
>
> looking with engine running.
>
> Mark
>
> > I am going to check more on the head. Do you
>
> think that a burst of air from
>
> > my compressor in the low pressure hole might
>
> free up anything, or do you
>
> > think it could be a mechanical casting problem?
>
> When the shop rebuilt the
>
> > engine they didn't see anything out of the
>
> ordinary and the bearings all
>
> > looked great for having 157k miles on them. The
>
> head isn't the original
>
> > head, from the previous owner it was replaced at
>
> 119k when the timing belt
>
> > broke. You could see the valve impressions in
>
> the tops of the pistons. It
>
> > ran great when I got it but the head gasket was
>
> shot, I had a coolant leak
>
> > and the coolant overflow was pressurizing,
>
> pulled the head and found the
>
> > leak in the gasket, that is when I decided to
>
> just pull the whole thing and
>
> > rebuild it. Just before I pulled it I put in a
>
> new oil pump and it was the
>
> > same. I also put in a good vacuum pump as well.
>
> I'm thinking there is a
>
> > blockage or lack there of in the head.
>
> >
>
> > -----Original Message-----
>
> > From: vwdiesel-bounces at vwfans.com
>
> [mailto:vwdiesel-bounces at vwfans.com] On
>
> > Behalf Of Mark Shepherd
>
> > Sent: Sunday, August 29, 2004 6:05 PM
>
> > To: vwdiesel at vwfans.com
>
> > Subject: [Vwdiesel] Nicks Pressure drop
>
> >
>
> > Since you have 70psi at the filter and a max of
>
> > 20 at the head then you
>
> > have a restriction (that's not supposed to be
>
> > there) somewhere in between.
>
> > The big problem with that is that you don't know
>
> > where that restriction is.
>
> > The filter itself, just inside thus restricting
>
> > oil to the bearings as well?
>
> > In
>
> > the head, the passage to the head, simply ahead
>
> of
>
> > the oil sender port?
>
> > Although it seem like sort of a non problem, I
>
> had
>
> > a similar situation
>
> > with a baja bug I had. It took out the crank
>
> > because the pressure port
>
> > wasn't the only thing with no pressure. :(
>
> > Loren
>
> >
>
> > This reminds me of a possibility that a crank
>
> > bearing could be drinking all the oil when warm.
>
> > My second Quantum had the crank bearing behind
>
> the
>
> > pulley badly damaged (from running dry?) by a
>
> > previous owner ;o( Head pressure would drop
>
> when
>
> > hotI didn't believe the warning buzzer cam dried
>
> > out and seized on two bearings and snapped the
>
> cam
>
> > belt (1.8gasser).... Sump off found problem; the
>
> > cam I freed with fine carborundum paste.
>
> > It ran perfectly until it died of rust and the
>
> > holes where rust used to be...
>
> > The Miser
>
> >
>
> > _______________________________________________
>
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>
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>
> >
>
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>
> >
>
>
>
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