zj Cooling problem

[Cooper]

So I have replaced litterally everything but the hoses for the cooling system. Radiator, thermostat, water pump, thermostat housing. It still over heats! Any other ideas anyone can suggest? I have the 5.9L engine. I even tried a lower temp thermostat.

 

[jeep-N-montero]

Did you try an OEM 195 degree thermostat and PROPERLY bleed the cooling system? Also, have you made sure the catalytic converter is not clogged up? BTW, from what I have read over the years about 1 out of 3 owners with the 5.9 have overheating issues. Which cooling fan are you running?

 

[Cooper]

I have tried with the oem thermostat. How do you properly bleed the system? The heater works amazing so I figured it was circulating. I didnt know a cat could cause it to overheat? I have an electric fan with a low and high speed. would removing the cat and just straight pipeing it work?

 

[Bart]

If the cat or muffler is clogged, the engine can't exhaust and it will run terrible and will overheat. I think the 5.9 is prone to overheating. Is the electric fan stock or aftermarket? Does it have a shroud?

 

[jeep-N-montero]

I have tried with the oem thermostat. How do you properly bleed the system? The heater works amazing so I figured it was circulating. I didnt know a cat could cause it to overheat? I have an electric fan with a low and high speed. would removing the cat and just straight pipeing it work?

Are you running that cheap fan setup that I warned against? If so then there is your problem. A clogged cat will cause it to overheat because that heat has nowhere to go.

 

[Cooper]

Its the one that it came.with.no shroud. I'll cut thecat out tonight and see what it does. That sounds like my best bet so far.

 

[bryson]

If it runs ok, just overheats, your cat likely is NOT the problem... The clogged cat will make the Jeep run poorly - no power. Don't cut it out unless you are sure it is the problem.

 

[jeep-N-montero]

Its the one that it came.with.no shroud. I'll cut thecat out tonight and see what it does. That sounds like my best bet so far.

There is your biggest issue, do you realize the function of the shroud is to pull cooler air through the radiator? I can almost guaranty that you are losing 40% or more of your cooling efficiency by not having the shroud in place. When did you swap in the 5.9 engine and is the fan in question the stock clutch fan, because I thought your Jeep was a 94 or 95 with the 5.2?

 

[sawtooth4x4]

i had a clogged cat on mine. i had the 5.2L. My wife drove it from Montana to Wyoming and back. It never ran right again. Had to sell it. Get it fixed and it'll definately help your overheating issues.

 

[Cooper]

I have the 98 ltd 5.9. It has never had a shroud and the heat issue started recently. I know the cat is bad so I am just going to hollow it out and weld it back on.

 

[jeep-N-montero]

I have the 98 ltd 5.9. It has never had a shroud and the heat issue started recently. I know the cat is bad so I am just going to hollow it out and weld it back on.

If you get caught during annual testing(and yes most intelligent inspectors can tell), your car will be flagged in the system, and if by some small chance one of our fine UHP officers catch you they can impound your vehicle. Very slim chance of the latter, but just an FYI. And BTW, the electric fan that came from the factory on all 5.9 limited models mounts to a shroud, so I'm not sure how yours is functioning, a picture would help.

 

[Cooper]

I'll post a pick tomorrow. Do they still do a visual check if its newer than 96? I thought they just plugged in their sweet machines. How would uhp know? I'm just curious. I just don't have the funds right now for a new cat. I'll get one eventually.

 

[jeep-N-montero]

Pictures?

 

[gertsch]

The cat is monitored by the computer and will turn on your check engine light causing it to fail the emissions inspection. Also the new analyzers read everything and store it in there main server that also can tell if its been programmed or modified. These new analyzers and crazy high teh and keep getting smarter.

 

[Cooper]

Sorry it took so long to reply. The fan does have a shroud that's how its connected like mentioned above. (Made an ass out of myself at auto zone arguing with the guy) the check engine light has been on for the cat for the last several years. I bought an adapter thee made the light go off and pass emissions. The cat should come off tomorrow.

 

[gertsch]

All shops should be doing visual inspections especially since everything they do now is be watched.