thanks so much for that info!
--- In ev_update@..., Dale Lucas <da_lucas@...> wrote:
Florian,
I had to ask my mechanic about the temp. switch as he didn't
record the part number on the bill.
So, he says for the Temp. switch it's: # 025 121 133-80, for the
plug to connect to the switch: # 893 903 231 Also, sometimes the Fan
Switch has to be changed, (but not in our case) # 251 959 481. I
assume these are common VW numbers.
Hope that helps.
One last comment: As the coolant that enters the trany heat
exchangers comes directly from the cylinder head, there is still the
opportunity for very hot water to go to the trany cooler. It did help
to get the fan on sooner and match the thermostat temperature, but
what really dropped the coolant temperature to the trany was the extra
cooler/radiator out in front of all the other radiators. Using a
surface temp scanner, the hose going to the trany cooler is
consistently 20 F cooler than the one leaving the engine.
My mechanic has offered to scan the transmission temperature while
we drive around one of these days. I just need to get over there when
everyone not to busy and the whole gang can go joy ridding.
Dale, 97 EVC
Portland, Oregon
Florian <fkahlert@...> wrote:
Just for curiosity - is this the switch we are talking about?
I am intruiged by this lower temp thing. I think that would just do
the trick and get the ATF temp out of the red zone.
Thx
Florian
--- In ev_update@..., Dale Lucas <da_lucas@> wrote:
All,
The Thermo. switch was changed out by our local non-dealer
mechanic. Because this lower temp. switch comes from an earlier model
VW, naturally the plug doesn't match so the mechanic changed the plug
on the wiring harness as well. He tells me that he does this to VWs
of all stripes, Vanagon waterboxers and Audis. (he also says that an
added benefit is that the engine running cooler reduces the tendency
for knocking/pinging, thus allowing the use of lower octane fuel,
although I haven't tried that)
The fans probably do run more, however I have noticed that after
cruising at speed (5 over the speed limit in California = 80+ with the
air temp. at 90+F) the fans are not running when we pull into a rest
stop, however they do come on in a minute or less. As for fans
failing, the general consensus on this site has been that the fans
fail when someone beats them up while working in the engine
compartment. (when I have to work around them I either insert a piece
of cardboard to protect them or remove them completely)
The cooler I used is from Summit Racing Equipment
www.summitracing.com model # DER-15502B, (cost $32.39 + shipping) it's
an "engine oil cooler" 3/4 inch thick with 1/2 inch tubing. As the
hoses coming out of the engine and going to the heat exchanger on top
of the trany. are approx. 3/4 inch. I.D., the larger the cooler tubing
the better. (this cooler was the only one they had that was thin
enough to fit behind the grill and in front of the AC heat exchanger
and that had at least 1/2 inch tubing.
For the plumbing part if this, I didn't cut any existing hoses but
disconnected the line coming from the engine and used a lot of brass
fittings to connect the new cooler into the coolant loop to the trany
heat exchanger. (the brass fittings can cost as much as the cooler,
and require more than one trip to the supplier) The new 3/4 inch
hoses where routed from the engine compartment to the grill area next
to the drivers side head light. there is some plastic shrouding that
can be cut away with a mat knife to allow the hoses though.
Dale, 97 EVC
Portland, Oregon
rvdalton <rvdalton@> wrote:
I wondered also if this was a stock thermostatic switch
(unscrew the
VW one and install this one in its place)? If a stock switch, what
temperatures are readily available and from what source? Are you
saying both fans come on at 176 F with the new switch?
From what I've heard the VW cooling system (although operating at too
high a temperature for the ATF) has good capacity. This might mean
that the 176F fan switch alone would keep the ATF cooler (without the
separate cooler). If that's the case it might be a choice between
operating the engine too cold (176F or lower?), and operating the ATF
too high (over 200F but depends on how often you want to change ATF)
Also a factor is that the fans have been known to disintegrate with
resulting damage to the radiator, so operating the fans nearly all the
time may not be the best choice.
Rob
--- In ev_update@..., "jd_boldt" <jd_boldt@> wrote:
--- In ev_update@..., Dale Lucas <da_lucas@> wrote:
...I added a lower temp. thermostatic switch for the fans (80c /
176f
) and a cooler just behind the grill to pre-cool the coolant before
entering the heat exchanger on the top of the transmission. So far,
the ATF seems to be staying below 170F, even in the extreme heat and
climbing hills.
Dale;
can you elaborate on your tranny pre-cooler, (where did you source
that?) I'm looking for one that will fit into the space. My
preliminary experiment using a heater core showed the precooler to
have a positive result, but the heater core will not fit between Rad
and grill (too thick, hoses in wrong spot)
Also did you change the engine thermostat and fan thermos yourself,
You can elaborate on that as well or email me, I need to do that
too.
I find the VR-6 and eurovan to challenge my previous VW-Diesel
skills.
janb
Washougal, WA
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