Date: Tue, 6 Jul 1999 04:12:10 MDT
Reply-To: CARY CHIANG <chiang1@USA.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: CARY CHIANG <chiang1@USA.NET>
Subject: Weird over-heating problem, please advise!
Content-Type: text/plain; charset=US-ASCII
Dear Listees:
I recently purchased an '85 Westy that the PO had warned me had a tendency
to overheat in traffic. I have owned several mid 80's vanagons and am quite
familiar with their cooling system and Bentley procedures, but this one has me
baffled. I 1st bled the cooling system per Bentley and got coolant flowing
out of the radiator bleed screw okay. After 10-15 minutes of idling, the temp
gauge climbs to about 3/5 and the red LED begins to flash. Increasing engine
speed to 2-3K for about 30 seconds brings the gauge back to the halfway mark
and turns off the LED. Another 4-5 minutes and the LED comes back on and the
gauge is again at 3/5. At this point, revving the engine does not cool it off
and the temp gauge soon hits maximum and coolant boils out of the overflow
tank. The radiator fan never turns on. So far I have:
Removed the thermostat
Tested the high and low speeds of the cooling fan
Tested the thermoswitch (ok but I swapped in a known good one)
Removed the radiator and thermoswitch and checked for obstructions using a
garden hose--good flow of water thru the inlet, outlet, and thermoswitch
mounting hole. Also inspected the core via the thermoswitch hole. The 11
rows visible had no signs of corrosion.
Flushed the rest of the system using the garden hose. Good flow of water both
directions.
Checked engine timing
I forgot to mention that the radiator is barely warm to the touch when the
engine is already boiling over, which explains why the cooling fan never turns
on. There seems to be a coolant flow problem at low rpm (revving the engine
at the 1st sign of overheating apparantly gets the coolant moving some). I
realize the water pump doesn't pump much at idle, but can it be worn out in
this regard (there is no pulley play or leakage) or do I have a leaking
cylinder head? If anyone has seen these symptoms or has any advice, please
respond directly to my address. TIA!!
Cary
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