Date:         Thu, 1 May 1997 21:02:21 -0700 (PDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         mcleans@earthlink.net (Ed McLean)
Subject:      Overheating? Try these ideas. (long)

Hi Folks,

There have been several postings recently concerning overheating of
wasserboxers in traffic and as the Summer approaches I just thought I would
summarize some of the information concerning overheating that I have
gathered over the past few years.  Many of these ideas have been posted on
the Vanagon list before and I apologize for not referencing the original
authors.  Thanks, however, should go to Dennis Haynes, Ed Buzz, Joel Walker
and others for some of these ideas.  The example used is my '86 Westi with
automatic transmission and 180,000 miles (engine rebuilt at 135,000 miles
because of low oil pressure and increasing rod bearing knock on startup).

I believe items 2, 5, and 6 are of most importance in this list!

1.  The inside of the radiator should be clean and all of the tubes should
be clear and free flowing.  You can check this by removing the radiator and
running hot water through it while feeling for heat over the entire front
and back.  If all is not clear, a radiator shop may be able to help.  A
mild radiator flush is also a good idea.

2.  It is equally as important that the OUTSIDE of the radiator also be
clean.  Since you already have the radiator out, a very effective method is
to spray some thin liquid detergent (such as 409 brand) on the outside of
the fins of the radiator and then hose it off with a strong spray of water.
The greasy dust that comes off will amaze you.  This dust can divert the
flow of air from going through the narrow passages between the fins and
totally destroy the heat transfer efficiency of the radiator.  CLEANING THE
OUTSIDE OF MY RADIATOR WAS ABSOLUTELY THE MOST SIGNIFICANT THING I DID TO
IMPROVE THE COOLING SYSTEM PERFORMANCE.  Before I washed the outside of the
radiator the coolant temperature gauge needle stayed clear above the red
light and sometimes it covered the little white dot near the top of the
gauge.  After washing, the needle stayed squarely on the red light except
when driving in town after a highway run.  Then the needle moved only
slightly above the center of the red light and soon returned to center.

3.  Flush out the remainder of the cooling system, reinstall the radiator,
fill and bleed.  The front of a '86 or newer Vanagon does not need to be
elevated to bleed the system.  It works fine if you just use the Bentley
method on level ground.  You can idle the engine at 2000 rpm by placing a
dime or penny under the adjustment screw on the throttle body to hold the
butterfly slightly open.  This makes bleeding an easy one person task.  I
use Prestone Long Life coolant (50% concentration).  Although some have
suggested there is a compatibility problem with this and other coolants, I
called Prestone's customer service 1-800 hotline and they said there was no
problem using this with other coolants but do not use it at higher than
recommended concentrations.

4.  I have also installed a slightly modified 82 degree Celsius  thermostat
(Pep Boys, Robertshaw 910-180) to replace the 87 degree C VW thermostat.
The modification was to trim the bottom disk to the same diameter as the VW
thermostat using a grinding wheel.  This dropped the coolant temperature
needle to the bottom half of the red light on the gauge.  I feel this small
change did slightly lower the oil temperature and thus increase the idle
oil pressure (see below).  This may be an insignificant effect, however.

5.  I use 15W50 Mobil 1 synthetic oil and Purolator or VW filters.

6.  I NEVER fill the crankcase oil level to the top of the operating range
on the dipstick.  I always keep the oil level between the bottom of the
operating range and 1/4 up from the bottom.  This lowered my oil
temperature (VDO drain plug sensor and electric gauge) from 255 degrees F
to 185 degrees F at 70 mph on a 80 degree day!  Usual oil temperature is
about 175 degrees F even in 30 degree weather.  Before reducing the oil
level, hot idle oil pressure was sometimes 1-2 psi.  Now it is generally 10
psi.  Hot, 3000 rpm oil pressure is 30 to 40 psi now.  The oil warning
light and buzzer came on a few times before I made these changes but they
never come on now.


I think attention to these few details has made a significant difference in
the durability of the engine.  They are certainly low cost items and I
believe they are worth consideration.  I know I certainly have a greater
peace of mind when I look down at the gauges.

I just thought it was worth putting these together in a single post.


Ed McLean
'86 Westi