Date: Tue, 10 Feb 2009 22:34:17 -0800
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Mocal sandwich plate plus oil cooler equals overcooling
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Hi John, nice to read all your thoughts.
the pressure caps on the expansion bottle are ............'iffy' .......
i.e. they don't work like they should........easily.
I'm sure you know that the purpose of having a pressurized cooling system is
to raise the boiling point of the coolant.
With a correctly working pressure cap your coolant should not boil until
well over 212 F ........
so you might want to try another cap.
Myself, I can't equate oil temps with rubber head gasket life.
I don't think those rubber gaskets really last all that well
anyway.......but they would have to be made out of a material that can
withstand say ...........275 degrees F.
perhaps try an infra red temp gun on your oil pan......see what numbers you
get that way.......to compare to your gauge oil temp readings.
I feel pretty strongly that high oil temps ....within reason of
course........can't have much affect on head gasket life.
it's possible of course........but the oil itself. and the rubber water
retention gaskets aren't even near each other.
if anything.......I'd say he rubber water gaskets deteriorate purely from
age, or corrosion from old yucky coolant, or the gasket gap being to small
and the gasket gets pinched.
you could shoot your infra red temp gun at the heads to see what them they
are running at.
sorry, but the only problem I see right now, if I have the whole picture, is
the oil is running way too cool........from either having the oil cooler in
the fist place, or a malfunction in the oil cooler system.
Didn't follow you about the baffles though. Air baffles to direct air flow
to the oil cooler ?
Scott
----- Original Message -----
From: "John Bange" <jbange@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, February 10, 2009 9:47 PM
Subject: Re: Mocal sandwich plate plus oil cooler equals overcooling
>> uh..........what's 'so wrong' with 220 F oil temps ?
>
> I probably should have added that my oil temp gauge is more of a
> relative temperature gauge, rather than an ACTUAL temperature gauge.
> The sensor is in the drain plug, and the wire to the gauge is long,
> undersized, and probably well corroded where the exhaust system has
> burned off the insulation. When I say 220F, that's just the line the
> gauge is pointing at. The REAL temp at the bottom of the sump is
> probably 10 degrees higher, and the actual temp at the oil gallery is
> certainly higher still.
>
>> Considering that oil temp is going to get up to coolant temp after a
>> while
>> anyway....
>> which is 185 F we'll say ..........
>> 225 is only 35 degrees higher than that......ie. 'not that much.'
>
> True, but it's definitely higher than that. I show signs of coolant
> boiling, which with a 50% mix blue Pentosin is at least 230F
>
>> also.......I think there is some unclarity about what exactly is 'too
>> hot'
>> in oil temps.
>> I regard 250 F as 'getting up there' ........
>> Perhaps in an air-cooled engine .....and even that isn't 'just horrible,'
>> I
>> don't think.
>
> Oh certainly. I've run higher than that through the 105F desert on a
> trip to Vegas. I would prefer not to though.
>
>> I think you're kinda chasing a problem that isn't there, especailly in
>> winter.
>
> Perhaps. Of course "winter" in Los Angeles included 80-90 degree
> periods lasting a week or so, and I spend a lot of time in stop and go
> traffic. My primary concern is the coolant boiling issue. Rubber head
> gaskets that are separated from hot cylinders by nothing but a bubble
> of steam can get very unhappy.
>
>> I'd want to see the stock oil cooler ( if 2.1 engine ) stay on the engine
>> anyway.....
>> since it also stabilzes oil temps by helping the oil to get warmed up
>> from
>> the coolant.
>
> Stock heat exchanger is still there. The sandwich plate attaches to
> the bottom of it.
>
>> There is a braod misconception in the non=rofessional automotive world
>> that
>> 'cooler is always better.'
>> ...
>> I'd say a little over 200 degrees F is about right.
>
> Yep, that's dead smack in the middle of the 180-220 ideal range out of
> the SAE handbook. 180 is considered the minimum necessary to drive
> fuel and water out of the oil, and 220 is about where pure water
> coolant and cheap single grade oil start to get flaky. Pentosin blue
> and Mobil 1 15W50 would let me go higher... but why would I want to?
>
>> perhaps your oil thermostat isn't working as it should.
>
> That's what I think. The temps were running consistently at the
> 180-190F (indicated) range at first before I installed the air
> baffles.
>
>> hey ! .......just thought of this .........since you are evidently very
>> concerned about proper engine lubrication......
>> send an oil sample out to an oil lab for analysis. That'll give you an
>> idea
>> about how much metal from the engine is showing up in the oil due to lack
>> of
>> proper lubrication or oil breakdown.
>
> Mostly concerned with the boiling coolant. I'm sure lubrication is fine.
>
>> You might like Amzoil. They claim
>> they are the only *true* synthetic oil.
>
> Amsoil? Meh. I buy whatever I can find. Usually Mobil 1. I know you
> think I'm chasing a phantom problem here, but hey, if an oil cooler
> saves me a gasket job, why not?
>
>
> --
> John Bange
> '90 Vanagon - "Lastwagen"
> '90 Vanagon GL - "Wiesel"
