Date: Tue, 27 Apr 2010 18:56:26 -0700
Reply-To: Don Hanson <dhanson928@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Don Hanson <dhanson928@GMAIL.COM>
Subject: Re: A little more on Cooling problems..inline vw in Vanagon
In-Reply-To: <BAY132-DS192B4121E1354AE662D5EEA0020@phx.gbl>
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Well gosh,
If all that can be wrong and must be repaired, I guess I'd best just visit
my nearby friendly German Car Junkyard and get another one...
I've heard the diesels have head problems...they run a lot of compression
and make gobs of torque for a little teeny motor...probably get a lot of low
rpm stress.
I've not heard much bad rap on the gas motors, but I can see how pushing
around a Vanagon might stress the motor a lot more than the rabbits they
were designed for...probably 3 times the gross weight and 3-4 times the
aerodynamic drag in a vanagon.
My headgasket failure when I first got this van was totally my own fault,
not a design failure. I simply overheated the motor badly, not realizing
the Vanagon cooling system could be partially air-locked by my faulty
cooling system bleeding.
Not surfacing the head after that incident was probably a mistake and I
bet that was partly to blame for an un-successful (well, it only lasted
about 35k miles) repair. I'll do better this time, or start over with
another runner from the scrap yard.
Don Hanson
On Tue, Apr 27, 2010 at 5:21 PM, Dennis Haynes <d23haynes57@hotmail.com>wrote:
> You're experience of a recurring failure with this engine is not uncommon.
> Typical failures for these head include warping, cracking, cam journal
> failure, and the head bolts loosing preload and the gasket then leaking.
>
> Any time the gasket fails you need to find out why. The head surface needs
> to be checked for straightness and flatness. If the head is warped, then
> the
> cam journals are also out of line the head is basically junk. The block
> also
> needs to be carefully checked. Yes they can twist also. A bad surface on
> the
> block can also cause the gasket to fail between cylinders.
>
> If the head is twisted, a proper repair involves straightening, the cam
> bearing caps get cut and the journals align bored. Milling the surface
> effects compression ratio and camshaft timing. Not much room here
> especially
> with Diesels.
>
> As for using compressed air to check for combustion chamber or gasket
> leaks,
> one cylinder at time, turn the engine until both valves are closed, secure
> the crankshaft, and then put as much air pressure as available into the
> cylinder. Use a spark plug adapter fitting. Any significant leak will
> result
> in air bubbling through the coolant. Remove the pressure cap and make sure
> the coolant is topped off to the rim so air does not escape from the top
> hose without passing through the coolant.
>
> Dennis.
>
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