Date: Tue, 6 Jul 1999 22:55:59 EDT
Reply-To: GREATCLOD@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rolf Pechukas <GREATCLOD@AOL.COM>
Subject: 82 diesel overheating
Content-Type: text/plain; charset="us-ascii"
dear listees:
persistent cooling problem in 82 vanagon diesel
history: bought the beast this spring not running because of overheating
PO diagnosed, maybe wrongly: head gasket
eventually replaced head (old one was cracked and warped), gasket, belts,
thermostat, etc
did NOT do the water pump (false economy)
ran fine and cool for one week? two?
then overheat
etc same thing over and over
traced it to persistent air in system from leaky tube from expansion tank to
overflow reservoir and me not knowing how to fill/bleed system
as I understand the system NOW, EVERYTHING needs to be totally filled and
air-free
you top up the system at the OVERFLOW behind the licence plate
DON'T break the vaccuum or introduce air at the expansion tank
as coolant cools and contracts more coolant is drawn into the system from the
overflow
is this right?
overheated again a month ago, this time brought it to a shop, they tried to
clear the system, apparently cleaned out a lot of oil from a previous head
gasket breach (!), but could not get the radiator circulating well
finally I bought a new radiator [from bus depot, reasonable price (best I
could find) and quality seems good]
again hunky dory for couple weeks
today was running so cool and sweet even in this hundred plus heat, but bang
without warning, red light
pulled over, the hose was blown off reservoir cap (served me right for using
cheap vinyl) steam shooting out, etc
thing is, I don't know if hose blew off because of overheating or if hose
blew off from not being tight enough and coolant ran out from normal pressure
at speed and loss of coolant caused overheat
anyway, refilled everything, new hose, running fine again
BUT
does this sound like more than air in system to anybody? the warnings about
water pump blade deterioration etc and the symptom of radiator not getting
normally hot sound familiar...
mech's original thought was thermostat, but that was brand new
and when I did the head (the old) radiator was getting hot uniformly
hmmm
other misc questions/observations:
few weeks ago had it idling for about 45 minutes at construction site after
dark so I could use headlights (this is right after new radiator went in so
felt confident)
kept going back to check temp, was fine fine fine then woops! red light, shut
down etc - attributed that to air bubble...?
also: upper hose from expansion tank fits over a fat rubber nipple that seems
designed to constrict flow - opening is tiny when it exists at all
today I slid a little catheter made out of a ball point pen body in there to
make sure it could flow some
what is this fitting supposed to look like???
I remember reading something somewhere about a 3mm constrictor - is this it?
the current one looks juryrigged by PO (is it jury or jerry? or jeri?)
also: replaced upper (low speed) fan sender with one from a rabbit cause I
busted one of the tabs off of the original one
is this a fair trade?
fan goes on when I short across the two terminals but I don't hear it going
on any other time, even when it overheats
could THIS have something to do with my predicament (duh)?
(note: I do believe the rabbit sender worked for a while)
also: instead of the fan going on and staying on occasionally like you would
expect even when you shut down the engine, something else seems to be turning
on and off sporadically - some small electric motor in right rear quarter of
vehicle, up underneath
too crazybusy to really look for it
mech thought it was a fuel pump - is that possible? never noticed hearing it
before the mysterious fan disappearance
ALSO: (and unrelated to cooling system, I think) my timing belt doesn't seem
to be tracking properly - even though all the pulleys and wheels seem to be
perfectly aligned when I eyeball the belt path, the belt runs @ 1/8" toward
the REAR of the vehicle, and the edge of the belt has been worn away by the
raised flanges of the tensioner and crank pulleys
mech said replace tensioner - I do have a new tensioner pulley, but before I
replace belt and have it do same thing over again, thought I would ask
anyone ever seen this before?
that's about it
(I love my rig and wouldn't trade it for anything
except a 99 european cargovan w/ poptop and TDI...
looked for a diesel for 3 years before I found this and I want to do
everything I can for it)
thanks for any feedback
Rolf
82 diesel (I understand why you guys name these things)
by the way: my current trial and error low tech method for filling cooling
system:
detach expansion tank cap and upper hose from expansion tank (the one on the
constrictor)
slip into the hose you removed a tight-fitting hose attached to a funnel so
that funnel is higher than top of radiator
fill gradually, letting all the air come up out of the block and head through
funnel
block constrictor(?) on expansion tank, continue filling to top of expansion
tank
replace cap and full hose from full overflow, remove upper fan sender on
radiator, continue filling till coolant starts coming out of sender hole,
replace sender, open bleed nipple, continue filling till coolant starts
coming out, close nipple, fill funnel one last time,
superquickunblockconstrictorpulloutfunneland hoseslambackhose on expansion
tank, tighten everything up
so far this is the best way I have found to eliminate air in system
is this acceptable?
no success with bleeding the Bently way
can't get engine to hold at @ 2000 RPM - injection pump seems to want to race
above a certain setting, and I don't think it's burning oil
oh, that's another thing: sticking accelerator, and it's not the cable, it's
something mechanical in the pump, you can feel it when you manually rotate
the lever arm - I ran 25$ fuel pump cleaner through the pump AND some
Stanadyne fuel conditioner - that seemed to almost fix it for about a day -
still better but sometimes still sticky - feels like the arm/pillar/spring
needs lubrication and I want to spray some kind of heavy duty gum dissolver
down in there
do I (hope hope not) need to rebuild pump?
thanks again
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