Date: Sun, 12 Sep 1999 19:32:06 -0400
Reply-To: John <johnpatt@WARWICK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John <johnpatt@WARWICK.NET>
Subject: Re: oil pressure problem
Content-Type: text/plain; charset=iso-8859-1
Bob Donalds wrote:
>
> Michael Y. Feng wrote:
> >
> > Hi,
> >
> > I was driving my 87 Vanagon out of town, and the oil pressure light and
> > buzzer came on after driving up a long grade. I immediately pulled over
> > and shut off the van. I waited about 10 seconds and started it up again.
> > This time no light for the next few minutes as I was almost at my
> > destination. As I drove home about the same distance, the oil pressure
> > light and buzzer came on again as I got very close to home. I shut it off
> > for a few seconds, started it up, and drove a little bit. It came on
> > again, though. Then I walked the rest of the way to my girlfriend's house
> > to eat dinner.
> >
> > I actually read my idiot's book by John Muir, and I think the oil pressure
> > relief valve may be sticking. In other words, as the engine gets hotter
> > the oil never passes through the oil cooler. The oil temperature
> > constantly goes up and eventually the oil breaks down. The oil level was
> > fine; as a matter of fact I just put in Mobil 1 oil a few days ago.
> > There's no oil leaking onto my driveway either. So, my diagnosis is that
> > the oil pressure relief valve is probably at fault.
> >
> > Question 1: do people on the list agree with my diagnosis?
> > Question 2: how in the world can I get that oil pressure relief valve off?
> > I've tried John Muir's screwdriver with pressure and a vice-grip to no
> > avail. Any other suggestions?
> >
> > TIA,
> >
> > Mike Feng
> >
> > P.S. To those of you who answered my oil drain plug question, I finally
> > found one in the tenth parts store I called for $2.05.
>
> Mike
> this is something I wrote for the vanagon.com pages its called low oil
> pressure at
> warm idle
>
> I have had more than one 2.1 water boxer engine brought in for
> rebuilding with
> symptoms of low oil pressure. Despite having put in the longest spring
> the customer
> could find for the pressure relief and adding thicker oil, the engine
> still had low oil
> pressure at a warm idle. These findings had been confirmed with a oil
> pressure gauge. So as I disassembled this engine I was very careful to
> check for excessive clearances.
> It turns out the clearance between the rod bearing and the crankshaft
> rod
> journal had gotten to the point that it allowed the oil light to come on
> at warm
> idle. While the crank usualy measures ok the rod bearing has worn and
> the clearance has almost doubled. Unfortunately the more common results
> of this problem in the 2.1 is that the rod winds up hanging out of a new
> vent hole its has created in the top of the
> crankcase. The 1.9 on the other hand is not known for throwing rods
> unless it was
> run low of coolant or oil.
> The one thing that has been consistent in all the 2.1 engines I have
> stripped and measured is that the large end of the connecting rods are
> no longer
> round. With this problem in mind I started paying more attention to
> the big ends
> of all the water boxer con rods that came into the shop. The first thing
> I found was
> that the 1.9 and the 2.1 con rods are the same size and length. In fact
> they are the
> same rods. My inspections showed the 2.1 rods had consistently more
> distortion at
> the big end. What is the difference between the two applications of the
> same con
> rod? The stroke is longer in the 2.1 engine so the rod angle is
> greater, plus the 2.1
> make more power witch puts more strain on the rods. It’s clear to me
> from my
> days at the race track that nothing distorts con rods faster than
> exceeding the
> power curve but the fuel injection has a nifty rev limiter built right
> in. This
> doesn’t explain why we see rod distortion in one engine and not the
> other. Next I
> went to the Bentley book to compare the torque specs. The 1.9 rod has a
> reusable
> rod bolt that call for a torque of 33-ft. lb. and the 2.1 rod bolt has
> torque of 22-ft. lb. plus ½ turn. The manual also says not to reuse con
> rod bolts on the 2.1 engines.
> The conclusions
>
> 1) NEVER reuse the 2.1 rod bolts
>
> 2) NEVER reuse the rods without having the big ends rebuilt ever!
>
> 3) NEVER rely on Plastagauge alone it does not always show if it’s out
> of round
> or if the cap is shifted.
>
> 4) Consider rebuilding your 2.1 waterboxer engine when the heads start
> to leak if it’s got a hundred thousand or more miles on it. Keep in
> mind the core may not be
> rebuildable if you wait longer. There is no doubt the increased rod
> bearing clearance is one of the major reason for the 2.1 engine
> catastrophic failures.
> .
> More than one person that has told me that they got only six thousand
> miles
> from the 2.1 long block they rebuilt before a rod blew through the case.
> They also told
> me they reused the rod bolts and the rods had not been measured or
> rebuilt. These facts speak for themselves. I see this problem on a
> daily basis and thought I should pass on my observations.
> hope this helps
> Bob Donalds
> Boston Engine Exchange
> www.bostonengine.com
Bravo Bob !
You really know what you're talking about !!!!!!!
Regards, JP
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