Date: Tue, 11 Jul 2000 10:40:47 -0400
Reply-To: Mark Gajewski <mgajewski@manvillerubber.com>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Gajewski <mgajewski@manvillerubber.com>
Subject: '85 GL pressurized cooling system
Content-Type: multipart/alternative;
Due to a number of factors I had to take a break from the list for the past year or so....but now I'm back with a continuing nuisance problem.
I need some advice...I have a long history of cooling system pressurizing problems with this van which all started after the water pump failed at about 75k. After resealing the heads a few times I found that it was just the left head that seemed responsible. So, I reseal the left head which solves the problem and it lasts about 10k before the cooling system starts getting pressurized again at which point I reseal the left head etc. Most recently the pressurizing got so bad that the seal on the left head catastrophically blew and I lost coolant to the ground for the first time. Assuming the left head was at fault again I resealed the left head, but this time it didn't fix the problem as I'm still getting pressurized coolant
Before going and trying the right head, or both, I performed the following tests.
-With a pressure gauge on the coolant tank I took a drive of about 5 miles @ 50-60mph. When I got home the gauge (a 15psi gauge) was pegged. This to me confirms that I have a compression leak over the barrels (or through the heads....to grandmother's house we go) and not just incomplete cooling system bleeding etc. Am I right?
- When the engine was cold, I released any cooling system pressure and I then took an air compressor and connected it to each spark plug hole, developed 65psi air pressure and held it for about 5 minutes on each cylinder. Watching the pressure cap gauge I was hoping I would see my coolant pressure gauge rise when I pressurized the faulty cylinder. No luck....the pressure cap gauge never budged over 0psi on the coolant. Why can't I duplicate the leak this way?????
My dilema is that the van is getting on in years and I don't feel like sinking a whole pile of money into it. Should I buy rebuilt heads? Should I pull the heads and have them tested somehow? If my pressure test didn't show up a problem, how would a bench test? Could I be doing something wrong that is causing this problem to recurr? What is the proper way to test the motor to isolate where the problem is?
Thanks,
Mark
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