Date:         Mon, 30 Jun 97 00:23:15 UT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Tom Brunson" <TABRUN@msn.com>
Subject:      RE: '87 Wf overheated on fwy; tank dry

Gail,

Don't feel bad about not noticing the temperature gauge - reminds me in '77 
when my 2-week old BMW 530 lost a coolant hose in Dallas and I didn't notice 
until the engine rev'd to about 4000 at idle. That engine was fine 'till I 
sold the car with 130,000 miles.

The Vanagon isn't likely to warp a head or anything from such an incedent. 
However you may find the cylinder water-jacket seals start to leak, as the 
bond to the heads may fail from high heat. If you notice dripping from this 
area I suggest you have it attended to - although it means pulling heads to 
replace the gasket. The aluminum head corrosion will really accellerate at a 
leakage point (you often find aluminum hose fittings quite corroded also on 
aluminum engines - all my VWs and BMWs) - and head corrosion is a major 
weakness of the Vanagon.

If it seems like the coolant disappeared suddenly look carefully for a leak - 
failed hose or waterpump seal - as soon as you re-fill and start the engine - 
and after it warms up. 

Watch for these symptoms:

The red indicator light should flash if the coolant gets low - that's the 
sensor in the top of the expansion tank (not the fill (overflow) tank). If the 
expansion tank is low and the light isn't flashing you should check the 
warning system.

The cooling fan on the '87 with AC has three speeds: Low is normal cooling 
from the (95C) sensor in the radiator or the A/C relay. Mid-speed is from the 
AC system high-pressure switch (kicks the fan higher if the freon pressure 
gets too high). High speed means the coolant temp is over 102C - this also 
cuts out the AC compressor. If your cooling system is in good shape the high 
speed should never kick in. (Even in  Texas summers - traffic jams at over 
100F.)

When it does - possible causes:

1) low coolant (It shouldn't drop - find the cause).
2) Bad radiator temp. switch (behind the lower grill on the driver side).
3) Bad series resistor (behind the driver side headlight)
4) Bad contact at connectors on any of the above.
5) Clogged radiator (or blocked airflow through radiator / condensor)
6) Blown fuse (30A S1) - the high speed uses a different 50A fuse
7) Head seal leaking into cooling system.

Both the low and mid fan speed run current through the series resistor behind 
the headlight. This is a big (green) ceramic wire-round resistor mounted on a 
little metal bracket because it gets HOT. On my '87 one wire in it melted 
through and - no low fan speed.  To test it, first just run the AC and see if 
the cooling fan is running. You can also pull the lower grill, unplug the 
coolant temp switch and jumper terminals 2&3 on the connector (note terminal 3 
is always live - even with ignition off). Low speed should check the mid speed 
part of the resistor too - since mid speed just uses half the windings. 
However on my '87 I had a bad contact at the mid-speed wire connector on the 
resistor, so mid speed wouldn't work anyway.

I hope this helps - cooling problems are a pain.

Tom Brunson
'87 Westy
'91 Carat
'93 EV
etc



>Hi Volks,

>A really elementary question, with which I would appreciate some help:

>Temps have been in the 90s in NoCA until the past couple of days :) and a
>loud fan has come on a number of times, usually on surface streets.  Usually
>running the A/C.  At first, i thot the accelerator was stuck, and tried
>stomping it down.  Then thot it was something to do with the A/C, so turned
>it off but of course, that was of no immediate help, tho probably related
>due to overworking the engine.  Then, i thot maybe it was the rapid or
>surging idle i've read about with some '87s.  After reading recent posts, I
>gather that the fan is part of the design, when the engine is overheating.

>The other day, the fan came on and didn't stop.  At a long traffic signal, i
>turned off the ignition, and then turned it back on--no change.  Slow-witted
>[blamed on heat and anoxia <low O2 to brain>], i turned off the A/C.
>Finally, it occurred to me to look at the temp. gauge, and Yikes!!! it was
>all the way to the extreme right edge of the dial.  I was almost home, so
>just took it as easy as possible for the last couple of blocks.  I looked in
>behind the license plate, and the water tank was completely empty.  
>
>I asked that all the fluids and systems be checked along with an oil change
>at the local VW dealer before a 1500-mi camping trip at the end of May.  The
>engine was  reportedly rebuilt in 9/96, perhaps 10-15k ago.  I have never
>observed any water leaks on the ground.  The red indicator light does come
>on at ignition [flashes on & off, then goes off], but has never come on
>while driving.

>My question is, Where do I start?  

>Because of all the discussion on the list of just the right coolant, etc.,
>and since i managed to make it home, i hesitated to just fill up the tank
>with water.  I have a Bentley manual, if someone wants to refer to that.

>Will appreciate any suggestions.  I've hesitated even to drive it because
>it's been so hot here, the the weekend has been beautiful and moderate.

>Thanks in advance,

>Gail  
__________________________
>Gail Fitzpatrick
>'87 GL Westi, 120k   [Twiga]
>Sacramento, CA         
<redwood@speedlink.com>