Date: Mon, 28 Nov 2011 07:58:28 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Oil pressure light in 1.9l at idle
In-Reply-To: <CA+n284Pc9AoFEKUpMi_hs5QJaMMrbwxurOouDgAOt=ZD84zcrg@mail.gmail.com>
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What speed is the engine idling at? Much below 850 will cause the light to
flicker. I set to 900-950.
Oil level? Be sure it is not overfilled. The top mark is not the full mark,
it is the "Max do not exceed no matter what" mark.
The Mobil 15w-50 is good down to near single digits. The Castrol 5w-50 seems
to thin out at higher temps even though it should be the same viscosity as
50 at 100C.
Is this an original engine with 100K on it or a rebuild? The 1.9L do wear
the bearing saddles and loos oil pressure over time. The owner's manual even
states that in some conditions the warning light will come on. It would be
good to test the oil pressure. The wear limit is 28 psi at 4,000 rpm.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
pickle vanagon
Sent: Sunday, November 27, 2011 10:27 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Oil pressure light in 1.9l at idle
On our returning-home-after-thanksgiving drive, we had some scary oil light
flicker.
Here are the details:
Engine has just a little over 100k miles on it.
I typically run Mobil 1 15w50 in it, but shortly before this drive changed
the oil to Castrol Syntec 5w50, hoping to achieve better lubrication during
cold-starts in the winter. I used a Mobil 1 filter (which I've used
occasionally before, though now it was replacing a Fram tough-guard).
Flicker definitely seemed related to oil pressure. That is: it only came on
after driving fast for a long block of time, and then letting the engine
drop to idle. After I first noticed a flicker happen once and confirming
the oil level was fine, I tried this experiment several times and could
often get some flickers out of it, although not always. Raising the engine
rpms *at all* would completely kill the flicker. I couldn't give it even a
tiny amount of gas and still have flicker, even after a long run.
Further mitigating factors:
We have an auxiliary battery setup with heavy gauge wire coupling the
batteries via a Stancor relay. The auxiliary battery is a year old or so
and so almost certainly in worse condition than the starter battery, since
that never gets drained at all. I have the batteries set up so that a
switch can be used to kill the stancor relay when driving (or force it to be
engaged when the engine is off). Anyways, with the stancor relay disabled,
I wouldn't get any oil light flicker, as the engine was idling high enough
to avoid it. The flicker was only happening after a long fast run *and* at
especially low rpms, which would only happen when both batteries where being
powered by the alternator.
Obviously I find this all pretty scary! I figure the first step is to
figure out what my oil pressure is at various operating speeds and
temperatures. So I've ordered parts to install an oil pressure gauge.
I realize there's a lower threshold (blue) .25 bar switch that VW recommends
to replace the existing .3 bar switch, which would likely eliminate my
flicker, but right now I'm just worried this is an indication of deeper
problems. I've ordered one of these switches anyways just in case my
current switch is bad, but the behavior I'm seeing rules out a wiring issue
I think, and I haven't actually heard of anyone having an old switch that
was still responding, but just at too high a pressure (if anything I would
expect them to fail in the other direction.)
I also realize the switch to castrol 5w50 may have been what made the
difference. But I'm reluctant to throw back in some 15w50, have the light
go back off, and then just call the problem solved... I mean, I shouldn't
really be that close to the edge of triggering the switch right? Or should
I be considering it likely that the 5w50 really was just too unstable in a
1.9l (which has no oil cooler) at high speeds?
I'll be grateful for any advice... wow, I hope this engine isn't giving up
on us!! I was planning on getting a lot more life out of it...
