91 overheating

"Randy Johnson" > wrote in message
...
> Not sure about right after the exhaust work. When it was done, the
> temperature gauge stopped working. That was replaced and all seemed well
at
> that time.
>
> We don't use the truck very much the past couple of years - about 4,000
> miles a year.
>
> The temperature problem became evident when we pulled out pop-up camper on
a
> trip that ended up abruptly in West Virginia when the pump blew out on the
> transmission. Stupid me had the transmission rebuilt instead of junking
the
> truck. Since then any time you go over 2,200 or so RPM - the temperature
> climbs about 30 seconds after you hit the gas.
>
> The radiator hoses are also new and don't appear like they could collapse.
> I havent found any that have the coil spring inside like some others.
>
> Any other ideas?
>
> Randy
> "Ulysses" > wrote in message
> ...
> >
> > "Ulysses" > wrote in message
> > ...
> >>
> >> "Randy Johnson" > wrote in message
> >> ...
> >> > Hello there -
> >> >
> >> > My '91 4 door automatic has been annoying me for a couple of years
now.
> >> >
> >> > Three years ago, the transmission was replaced, exhaust also. Since
> > then,
> >> i
> >> > have had an overheating problem while accelerating. Any thing over
> >> > 2500
> >> > will make the temperature jump.
> >> >
> >> > I have replaced the guage sender, the radiator, hoses, water pump and
> > fun
> >> > clutch over the past few years as these were more or less worn out.
> >> >
> >> > To make things livable, i have drilled a couple of extra holes in the
> >> > thermostat. It takes a while to warm up, but the temp sits at the
"o"
> > in
> >> > normal. Hit the gas and watch it jump for a minute or two and go
back
> > to
> >> > where it started. Yes, the engine really does get hot. Without the
> >> holes,
> >> > i was overheating when it was 15 below zero. Tried replacing the
> >> > oxygen
> >> > sensor - no change.
> >> >
> >> > It doesn't matter if driving or reving in neutral - same thing - temp
> >> spike
> >> > when accelerating.
> >> >
> >> > Sounds like it is running lean?
> >> >
> >> > 190,000 miles.
> >> >
> >> > Could it be an issue with our newer blends of gas?
> >> >
> >> > Help,
> >> >
> >> > Randy
> >> >
> >> >
> >> Did it begin when when the exhaust was replaced? I have not had this
> >> particular problem yet but while researching MY overheating problems I
> > read
> >> that a blocked catalytic converter could cause overheating.
> >>
> >> I'm about to replace my radiator and fan clutch in a few minutes. I'm
> >> pretty sure my fan clutch is bad (it turns freely when the engine is
hot
> > and
> >> I never get that "whoosh" sound any more) and my radiator is clogged.
If
> >> that doesn't work I'll be doing all the other things that you did (not
> > sure
> >> about drilling holes in my thermostat though) so please post any
progress
> >> you make and solutions you may find. I thought I'd solved the problem
on
> > my
> >> '92 but the temp gauge went up while I was going up a steep hill. The
> > rest
> >> of the time the temp gauge barely moves. I put in a new thermostat not
> > very
> >> long ago. I guess I'll have to yank it out and test it. At least it's
> > not
> >> dumping coolant any more when I shut off the engine. My '91 is close
to
> >> being undrivable right now unless the outside temp is 90 F or less.
> >>
> >>
> > Well, my fan clutch was all oil and goopy on the thermostat and there
was
> > so
> > much mud on the radiator that it was probably only working about 15-20%.
> > Considering that I now have 3 Exploders I decided to just go ahead and
put
> > in the new radiator and keep the old one for a spare.
> >
> > I went up some steep dirt hills in 4WD with the AC on and now the temp
> > goes
> > up about halfway (100 F here today) and then drops back down to about
one
> > forth of the way up. It will now idle at a stop with the AC on without
> > overheating. That's a big improvement but I have not given it the windy
> > mountain road test yet.
> >
> >
> >

First of all *most* of us have had the transmission repaired/replaced and I
have no regrets (did it on 2 Explorers, 91 and 92).

Ok, here's what I did, for what it's worth. I replaced the radiator and cap
on both Explorers (both were overheating and boiling over the reservoir
after the engine was shut off. The '92 was billowing white smoke when it
was first started in the morning. I replace the fan clutch on the '91. On
BOTH I added a can of J&B Stop Leak. The '91 is now pretty much perfect
except the new fan clutch seems to be causing a lot of noise. The white
smoke is gone on the '92 and one time going up a hill the temp gauge went up
to about halfway and then went back down. I think the thermostat may be
sticking open most of the time so I need to check that.

The reason I used the stop leak in new radiators was to try to determine if
there was a coolant leak in the heads or someplace. If there was the J&B
seems to have stopped it. I'm thinking I was getting some exhaust into the
coolant on both Exploders and that was causing air pockets in the coolant
and bubbling in the reservoir. I also think my radiators were clogged.

The J&B stop leak says it fixes cracks heads and leaking head gaskets. I
don't know how long it will last but for $5 I'd say it's worth a try
especially if it is barfing coolant out of the reservoir after you shut it
off.


>