Date:         Thu, 21 Mar 1996 13:32:00 -0800 (PST)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Maher, Steve (SD-MS)" <SMAHER@gi.com>
Subject:      RE: Followup: engine cooling non-problem


Well, the hits just keep comin' in...

Some things I didn't specify, sorry:

I've heard that watercooled vanagons have the cooling-fan switch
mounted on the radiator, so the fan comes on when the radiator is
hot enough (true?)

However, in the V6anagon, the Chevy 2800 in it, has both the temp
gauge sensor and the radiator-fan sensor switch, mounted on the
engine itself, very close together near the hot-water outlet that sends
the coolant from the engine to the radiator. So, in theory, both the fan
and the gauge should keep pretty much in step with the actual temperature
of the engine.

The thermostat of this beast, is mounted just downstream of these
two temp sensors-- as usual, right where the hose leaves the engine.
It may well be stuck open-- I've had this happen in cars that have sat
for a while (months), as the V6anagon did after the PO fried the clutch.
Or, there may not even be a thermostat mounted in there-- a common
hot-weather California trick, tho it's a bad idea (slow warmup,
inconsistent running temp).

Anyway, from the way the car ran so cool back when the fan was running
continuously (the thermostat should have choked off most of the flow at
cooler temps, making the cooling fan irrelevant-- Citations take a 195
thermostat that doesn't open till the engine's pretty warm), I have a
hunch there's either a bad thermostat, or none at all.

BUT... (here's grist for all you V6anagon hecklers' mills) the thermostat
housing on this fore-and-aft mounted V6, is directly under the sheet metal
that's under the front (FIF) of the engine hatch. It's jammed right up
against the edge of the metal, where the air seal probably goes in the
T4 engine installation, and offhand looks like a real b*tch to get
to, tho I haven't tried yet. The PO said that, to replace the clutch,
he removed the mounts for the engine and tranny, lowered the whole
shebang to the ground(!), and then jacked up the bus around it. I may
need to copy this trick. Maybe in the summer, also to re-mount the
water pump cover which has a ton of permatex squeezing out from under it
and leaks oil.

As regards plumbing, the PO did indeed route the heater outlets to the
heater, and the radiator outlets to the radiator. Size difference in the
outlets make that almost impossible to get wrong (famous last words).
However, he did use fairly narrow radiator hoses to the radiator-- they
are actually very large (and very long!) heater hoses, 1" inside diameter,
which I'm sure are smaller diameter than the original Citation radiator
hoses. But, when everything's working, it seems to have plenty of cooling
capacity. Control of that capacity seems to be the problem now, which I'm
just starting to get a handle on. Now that the fan's doing its thing as
designed, I hope that a thermostat replacemant and coolant-recovery tank,
will complete the puzzle.

Thanks again for the help, friends!   :^)

>Steve especially,
>
>Your test verified that coolant is circulating, your new fan switch works,
>and that your temperature gauge seems OK.  However, in an earlier post, you 

>mentioned a running temperature of 160 degrees F.  That's too cool.  In
>fact, that is why I rambled on before about either an engine thermostat
>(not fan thermostat) problem, or, since you have a transplant, an error in
>the plumbing of the heater and coolant hoses.  I believe that you still
>have a problem.
>
>Greg especially,
>
>The temperature gauge reports the engine temperature.  As long as the water 

>in the circuit is below the thermostat temperature, the engine runs at its
>usual 190 degrees F.  However, at a prolonged idle, the whole cooling
>circuit just keeps getting hotter because there is no cool water available
>from the radiator part of the circuit.  No airflow, no cool.  Eventually,
>when the whole system gets to 200+ degrees F, the fan thermostat on the
>radiator turns on and hopefully prevents any further increase in
>temperature.  However, after a few degrees cooling, the fan shuts off
>because the radiator temperature has fallen below the fan thermostat's off
>temperature, and the cycle starts over.  Thus, the way to bring the engine
>back down to normal is to turn it off, or to drive.


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 Steve Maher   smaher@gi.com       '80 V6anagon w/Chevy 2800
                                   '66 Mustang Coupevertible, for sale

 Check out the cars at http://www.lookup.com/homepages/76242/home.html

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