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Modine or GDI Radiator...

Rock.Wgn

NAXJA Forum User
Location
San Diego
I have a 95XJ that is starting to heat up on the freeway. I have replaced the water pump and thermostat recently. My fan clutch seems fine. I have a GDI 3-row radiator with about 35,000 miles. I feel my problem is the radiator might be getting clogged. I can yank it out and have it rodded for about $75 to $80 bucks, or I can get a new Modine as a replacement. I have been hearing more negative than positive on the GDI. What are your opinions? And where is a good source for a new Modine 2-row.
Thanks,
Sean
 
NAPA carries the Modine. But I found it about $30 cheaper at a small rad. shop. JIM.
 
My money is on your fan clutch! If you don't hear the fan whirring lots of air then it's bad. Just replaced the one on my son's 96 xj. Also what makes you think your radiator is clogged with only 35k on it?

JoBo
 
JoBo said:
My money is on your fan clutch! If you don't hear the fan whirring lots of air then it's bad. Just replaced the one on my son's 96 xj. Also what makes you think your radiator is clogged with only 35k on it?

JoBo
The fan clutch failure would cause overheating at SLOW speed, NOT at freeway speeds, as is the case here. At freeway speeds, the movement of the vehicle alone provides plenty of air for cooling.

The problem here is the rad--it's either plugged up inside with crud in the tubes, or the fins are full of mud, bugs, etc.
 
AZ Jeff said:
The fan clutch failure would cause overheating at SLOW speed, NOT at freeway speeds, as is the case here. At freeway speeds, the movement of the vehicle alone provides plenty of air for cooling.

The problem here is the rad--it's either plugged up inside with crud in the tubes, or the fins are full of mud, bugs, etc.

You would think so but on my son's 96 it overheated more driving on the freeway then sitting still. I once had a vw that had bugs in the radiator and it overheated on the highway as you discribe but not in stop and go drving.

JoBo
 
Interesting that you said you replaced the waterpump and thermostat recently. Is this when the problem started? You could have an air pocket or a bad thermostat.
 
Overheating at freeway speeds has turned out (for me) to be a radiator partially blocked on the outside front (wifes 95), with the white stuff from the cotton wood trees that are common around here. Another time, the spring inside of the lower radiator hose slipped and allowed the hose to partially collapse at freeway speeds. Once, it was partially plugged radiator (9 years old), that overheated a bit at all speeds, I could see a lot of white junk, inside the bottom of the radiator through the outlet hole with a flashlight (I now use distilled water).
Had the guy at the parts store, try and give me a water pump (for my 87), with an impeller, that was a mirror image of mine. I didn´t install it, caught it in time, but the results probably wouldn´t have been good. A reverse rotation pump, will pump in the proper direction (dispite what logic tells you), but very poorly.
A very lean motor will overheat at freeway speeds (my 88, bad 02 sensor).
A head gasket leaking exhaust into the cooling system (a buddies WJ, fairly rare), will overheat the motor at freeway speeds. The coolant recovery bottle, will often smell like exhaust fumes. If you have to regularly add a little coolant, a head gasket is a possiblilty. when the motor was stopped the pressure in the cooling system, was pushing a little coolant past a leaky head gasket into a cylinder, (which added up over time). The real tip off was, that the condensation moisture, that was blowing out of the exhaust at start up, had a green tint to it (from the Prestone he was using).
A very minor coolant leak (on a hose somewhere), when the motor cools down, can suck some air into places it shouldn´t be. Not so much a problem with the OBD series XJ´s, but I´d guess, even the open system takes awhile to purge air traps.
I recently bought a replacement Modine (from an autoparts retailer), don´t know if it was a knock off, made in China or what, but I wasn´t impressed with the craftmanship.
 
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Agreed. I was told Modine was the best and all that, but I got mine and I wasn't impressed at all. Looked like a cheap China radiator too me. Paid close to $200 for it too.
 
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