[Vwdiesel] Nicks oil pressure problem

[mikitka]

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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