Date: Fri, 13 Feb 2009 11:19:08 -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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will try to keep this short.
I am under the impression that The Issue is ........
it runs at proper cooling system temp,,,,,,,,,but there is bubbling in the
coolant pressure bottle.
( couldn't quite decipher this : "the bubbles vanish as> soon as the his
the pressure tank and condense." )
tell me this ............does coolant disappear in any way, ever ?
are 'the only symptoms' that the coolant bubbles and the oil is too cool ?
in all cases of mysterious unsolvable problems, I say..........go back to
the basics.
starting with a leak down test.
I had a very nice case recently where doing a leak down test on each
cylinder, with the pressure bottle cap removed, so coolant level in it could
be observed.............on # 2 cylinder there was a very distinct rising of
the coolant level in the pressure bottle while leak down testing that
cylinder.
Once the head was pulled it was quite obvious there had been coolant in the
combustion chambers of that head.
It is possible to have a water pump that doesn't leak or show any of the
common water pump failure modes, and it still fails to pump
correctly..........but that is extremely rare. The most likely reason that
would ever occur is a odd aftermarket water pump that's not quite built to
correct specs in the first place......
There is also corrosion of the water pump housing, ( reducing head
pressure that the pump can produce ) ..... .............which is part of the
block on a waterboxer.........
but that's pretty rare too.
Scott
----- Original Message -----
From: "John Bange" <jbange@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, February 12, 2009 6:17 PM
Subject: Re: Mocal sandwich plate plus oil cooler equals overcooling
>> I fear that boiling antifreeze is a sign of more than hot oil. Where
>> does
>> the coolant temperature gauge needle sit during all of this?
>
> Dead center on the LED, rising a needle's width above until the
> radiator fan kicks on, which drops it back down. It's been almost
> ridiculously reliable in this regard.
>
>> Just a WAG but
>> I thing you might have a failing water pump allowing hotspots to form in
>> the
>> engine.
>
> This is a possibility, but if so, it's been failing in exactly the
> same way without getting worse for 4 years and 20K miles. I get enough
> heat out of the heater core to turn the inside into a sauna, so I'm
> definitely seeing good water flow. It's not an exhaust leak, since I
> only see bubbles after I stop the engine, and the bubbles vanish as
> soon as the his the pressure tank and condense.
>
>> Possibly the radiator is on it's way out also.
>
> Well, the radiator was changed when I changed the engine, and I have
> good, solidly normal coolant temperatures. I suppose I COULD change
> the water pump on the off chance that's the issue, but it doesn't seem
> like that the problem. I'm just seeing alot of heat from the bottom
> end and the top end cooling system just can't keep up with it
> effectively. It probably doesn't help that I'm hauling heavy stuff up
> hills in the heat with an automatic transmission--- that's yet another
> pretty good heat generator there. The oil cooler has so far worked
> wonderfully, until the thermostat stuck open.
>
> --
> John Bange
> '90 Vanagon - "Lastwagen"
> '90 Vanagon GL - "Wiesel"
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