Date: Tue, 27 Apr 2010 20:21:14 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: A little more on Cooling problems..inline vw in Vanagon
In-Reply-To: <v2z6bc66ccf1004270734r86c60aeft4e5d5fcf96315e7d@mail.gmail.com>
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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.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Don Hanson
Sent: Tuesday, April 27, 2010 10:34 AM
To: vanagon@GERRY.VANAGON.COM
Subject: A little more on Cooling problems..inline vw in vanagon
Yesterday I went over my '92 Golf/Jetta/Rabbit gas-powered 1.8liter VW
inline van (84 low top westie) following up on some suggestions from helpful
list members, chasing down some strange cooling system behavior I began
seeing recently.
I've seen a change to cooler than normal operating temps...until it
boiled over on Sunday. I've had excess coolant level in the overflow tank,
too. No loss of power or poor running..just the temperature anomalies.
So I pulled the plugs (they alll look perfect) and put about 20psi
compressed air into the coolant pressure tank, then listened (with a pipe)
to each spark plug hole for escaping coolant coming into the cylinder.
Nothing. I blew out the pressure cap on the coolant pressure res. and
replaced the hose to the overflow tank..it was a bit old and possibly
leaky. I found my spare thermostat and tested it in boiling water, then
replaced the one in the van with that. I shut down the valve to the rear
heater and inspected all the hoses and connections everywhere. Then I
re-filled and re-bled the cooling system very carefully.
Alas! I still see some bubbles coming into the pressure
reservoir..confirming I probably will still see head gasket or head (proper)
problems. So I found and ordered parts online..$31 for the headgasket and
$27 for new headbolts and washers. When those arrive, I'll be pulling the
head (which you can do with the motor in the van) to see where the
combustion gasses are escaping into the coolant.
I've also been putting off installing a billet aluminum fuel injector rail
(fire prevention measure), now I can do that. If the head is not damaged, I
don't even have to touch the valves or camshaft, so the R&R of the
headgasket should be about 1/2 day's process...if I don't break anything and
do it correctly the first time.
I'm posting this to perhaps give some data to those with problematic
motors in vanagons. To those who may be debating either fixing their engine
problems, rebuilding their existing motors or choosing one of the
engine-swaps, you might be interested in the relative repair simplicity and
economy of an inline VW gas motors. I am not advocating "My" type engine as
the best in a vanagon...I am truthfully relating the experience I've had.
I've been finding this van remarkably inexpensive and simple with adequate
performance and good fuel consumption. ~$60 and half a day in your garage
with hand tools, you can't beat that for a leaky combustion chamber problem
repair, can ya? (I know..."Best case scenario only")
I probably should have had the head surfaced professionally when I
replaced a headgasket about 35k miles ago. That time, I screwed up the
bleeding process, being new to Vanagon cooling systems, and overheated my
motor. I assessed the head's true-ness with my steel carpenter's framing
square, then lapped it a little on a piece of plate glass, deciding that was
probably "good enuf" but I probably should have sent it out to a
machinist..
Don Hanson
