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Installation
date: 7/15/00
The
Jeep 4.0L engine is designed to run "hot", about 210* F,
but running too hot, like around 235*+ F can eventually cause serious
damage and dramatically reduce engine life. Not to mention you could
overheat and get stuck on the side of the road.
For
the first five years of its life, my Jeep ran at 210* all the time,
regardless of what I was doing, and it would never pass the 210* mark.
But then this past summer for some reason it decided to start overheating.
It never got to the point of boilover, but it ran very close to the
red zone on a couple of occasions, and this was on the highway cruising
at 70mph. This was enough to worry me and something had to be done.
After
talking with a number of people about my cooling problems, I finally
decided my thermostat was sticking and I probably needed to flush
the radiator. I also found that the general consensus was that the
factory plastic 1-core radiator wasn't really up to the task of properly
cooling the big 4.0L in hot climates. After hearing lots of good things
about the GDI 3-core radiator, I decided to try one out and see what
effect that had on my cooling situation. The GDI 3-core is available
for both the closed and open cooling systems the Jeep Cherokee has
used over the years so be sure you specify which system you've got
when ordering.
As you
can see in the photo, the GDI's side reservoirs are much larger
than the factory unit's, and the radiator itself is about
half again as thick as the factory one. The radiator comes
with fittings for the transmission fluid lines if you've got
an automatic, or you can use the supplied "plugs"
if you've got a manual tranny.
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The first
part of the installation is to let the engine completely cool
down. I'd recommend letting it cool overnight and starting the
project the next morning. Once the engine has cooled you'll
need to drain the coolant from the radiator. The drain "spout"
is located in the bottom left corner of the radiator when looking
at it from the front. Put some tubing on the spout or position
a funnel and container underneath it and loosen the spout a
couple of turns, coolant should start flowing out. Remember
to be careful when dealing with coolant, it can damage paint
and it is very toxic to animals, which just happen to like the
smell.
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While you're
waiting for all the coolant to drain out, start unbolting and
removing the grill reinforcement panel, the radiator crossmember,
the electrical fan (is you've got one) and the radiator fan
shroud, in that order.
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Next you'll
need to unbolt the radiator from the AC condenser, if you've
got AC. Also, if you've got the automatic transmission, you'll
need to unbolt the lower tranny line from the bottom of the
radiator.
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Once all
the coolant has drained from the radiator and you've removed
everything from around it, unclamp all the radiator hoses and
transmission lines (if so equipped) and pull the radiator out.
Be careful when you pull off the bottom radiator line, unless
you drained the coolant from the engine block, this lower line
will still have lots of coolant in it... Also, the return line
for the tranny fluid is tricky to get off. It takes just the
right abount of squeezing the "ears" and pulling on
the line to get it off. When you look at it, you'll see what
I'm talking about.
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If you're
replacing your thermostat as well, go ahead and remove the radiator
hose, heater hose, and temperature sensor from the thermostat
housing and unbolt it from the engine. The lower housing bolt
is blocked by the serpentine belt, which makes getting it out
and back in a bit of a PITA. There will probably be some coolant
still in the top of the engine, so be prepared when you pull
off the housing and remove the old thermostat. Once you've removed
the old thermostat, stuff a paper towel or something in the
hole and scrape off all the old gasket material.
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I decided
that since I was going to the trouble of installing a new
thermostat, I though that I'd go ahead and replace the factory
housing with a high-flow model from TurboCity. If you look
at the full size version of the photo, you can see where the
TurboCity housing has been ported out for higher flow. Whether
this actually makes any difference is still to be debated,
but I figure it couldn't hurt. I also decided to replace the
thermostat with a slightly lower temp unit to deal with the
hotter weather down here in Texas. The factory thermostat
is set for 195*, so I bought a 180* unit by RobertShaw.
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The TurboCity
thermostat housing comes with a new paper gasket, and you'll
want to use some silicon gasket maker in addition to the TC
gasket to get the housing to completely seal. It might also
be a good idea to put a spot of silicon on the thermostat
to help hold it in while you're positioning the housing, because
if the thermostat slips out of it's seat it's hard to tell
and it could damage the housing when you tighten down the
bolts.
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If you've
got the automatic transmission, install the new fittings in
the radiator before setting it in the vehicle, and be sure
to use teflon tape around the threads so they don't leak.
I had some clearance problems between the lower trans line
(the return line) fitting and the fender, but it wasn't anything
a little work with a prybar couldn't fix. The paper towel
is stuffed in the radiator opening to keep debris from getting
in during installation.
When you're
putting the new radiator in, it makes life much easier if
you put the radiator fan should in before the radiator itself.
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Once the radiator
and fans is in place, bolt everything back down and reconnect the
tranny and radiator lines. You'll need at least a gallon of coolant
to get a 50-50 mixture, so make sure you've got a full container
or two of coolant before you start the install. After refilling
the radiator, leave the cap off and run the engine until it's reached
it's normal operating temperature, then add cooolant/water to the
radiator as needed to get the system completely filled. Be sure
to check for leaks. If everything looks fine and isn't leaking you're
ready to go. I didn't notice any drop in tranny fluid after the
install, so I didn't need to add any more fluid, but be sure to
check the level if you've got the automatic transmission just in
case.
The new radiator
and thermostat definitely took care of my cooling problems. My rig
runs at about 180* for the first 30-40 minutes of driving then warms
to about 200-205*. It still hits 210-215* every now and then during
traffic or cruising on the highway (pushing 33's with stock gears
and the AC on max probably works the engine a little hard), but
for the 100+*F we've been having here in Texas, I figure it's doing
pretty good. If you're considering a new radiator, I'd highly recommend
the GDI 3-Core. I think you'd be hard-pressed to find a better radiator
for a cheaper price.
For
more information, contact:
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