Over Heating

[jwill22]

I was wondering what it could be that's causing my jeep to over heat when its parked running or in neutral. If I'm driving her around it does just fine, no over heating, but if i stay in stationary position, or I'm stuck at a drive thru and ive been sitting there for 3 t0 5 minutes she begins to overheat. I changed out the thermostat, hoses look fine. I only over heat when im sitting somewhere and not while im driving, I'm guess cause the wind helps the fan turn a bit more. Any Ideas?

 

[TroyaCantrell]

Overheating while sitting still means you are getting enough airflow across the engine while driving to exchange the heat but not while sitting. If you can tell us a bit more about your setup it would help.

Any mods done to it we shoul know about?

Do you still have a fan shroud on the radiator? Could be a failed clutch on the fan itself, if it has one.

What does the fan look like if you open the hood and look while it is running. Is it spinning at the same speed as the crank? Does it spin free with the engine off?

Any water leakage/ loss? How old is the water pump? Does the oil on the dipstick look milky or frofy ?

 

[tarry99]

I was wondering what it could be that's causing my jeep to over heat when its parked running or in neutral. If I'm driving her around it does just fine, no over heating, but if i stay in stationary position, or I'm stuck at a drive thru and ive been sitting there for 3 t0 5 minutes she begins to overheat. I changed out the thermostat, hoses look fine. I only over heat when im sitting somewhere and not while im driving, I'm guess cause the wind helps the fan turn a bit more. Any Ideas?

Air flow as previously mentioned across and through the radiator is the key..........You sound like you could use either a better belt driven mechanical fan blade (more pitch & blades) or adding an electrical fan that operates via a thermostat and comes on when overheating..........keep in mind there could be other things that perhaps you have added or changed that may also be causing this.........may even be your Radiator & block just need flushing?

 

[jwill22]

Well I did change out the radiator fluid. I drained it out then threw in some new coolant. Like stated before i replaced the thermostat. No Mods. I am having some carb issues though, i can't seem to get it to idle :/
By spin free while the engine is off mean that i can turn it myself. Then Yes. The Oil looks fine. I did have the engine replaced like 3 years ago. I think i have the original fan that came with the jeep. So i assume that's the fan shroud. The water pump is as old as the engine, because that was replaced along with the engine overhaul.
I could attach a picture if needed .

 

[jwill22]

oh and no visible leaks. I do have a leak that looks to be coming from my Transfer Case though :/

 

[tarry99]

Well I did change out the radiator fluid. I drained it out then threw in some new coolant. Like stated before i replaced the thermostat. No Mods. I am having some carb issues though, i can't seem to get it to idle :/
By spin free while the engine is off mean that i can turn it myself. Then Yes. The Oil looks fine. I did have the engine replaced like 3 years ago. I think i have the original fan that came with the jeep. So i assume that's the fan shroud. The water pump is as old as the engine, because that was replaced along with the engine overhaul.
I could attach a picture if needed .

Does your fan have a clutch housing attached? It is normally aluminum and has fins on it?
When cold the fan should not turn without some resistance..........when hot and there is considerable air flow coming through the Radiator the clutch releases the fan somewhat allowing it to spin just by the air moving by it........hence the reason they call it a clutch fan........but again cold if it is not locked up it will not draw much air and therefore no cooling.

 

[jwill22]

the inside of the hood!

 

[jwill22]

seems like i can still rotate the fan even when its cold, with not much resistance.

 

[BusaDave9]

I agree with tarry99
Sounds like a bad fan clutch

 

[mtnwhlr]

I think it is because he doesn't have a shroud.

 

[tarry99]

I think it is because he doesn't have a shroud.

I would agree with both , bad clutch hub and would surely be more efficient with a shroud around the fan blade...........someone took yours off.

 

[jwill22]

What size of shroud would be recommended?? I see there is a 5 1/2 in and a 3in one. ?? Or can you give me an example of one i could use?

 

[BusaDave9]

What size of shroud would be recommended?? I see there is a 5 1/2 in and a 3in one. ?? Or can you give me an example of one i could use?

The difference is the engine. I think the 3 inch shroud is for the I6 and the 5.5 inch is for a four banger.
Just get an OEM shroud for your engine.
One reason people remove the shroud is the fan will hit if you install a body lift.
If you have a body lift the shroud will need to be modified.

 

[tarry99]

What size of shroud would be recommended?? I see there is a 5 1/2 in and a 3in one. ?? Or can you give me an example of one i could use?

I agree with Busa..........find an OME one that fits your Radiator & Fan size. If you or someone else has changed either then you have to do some measuring to get both to fit together.........point is you want to cover up the perimeters of the radiator with the shroud so it directs the air flow to the fan blade which then aids the fan blade to pull more air...........get your tape measure out and find a Jeep wrecking yard......or look on line.

 

[BusaDave9]

I see there is a 5 1/2 in and a 3in one. ??

That is much too small for the fan size so I assume that measurement is how far the shroud extends out from the radiator. A four popper sits back further from the radiator and needs the longer shroud.

Replace the fan clutch at the same time. I think we all agree your problem is air flow but I don't think the shroud alone will fix this. My AMC 304 doesn't have a shroud (but it should) and it still never overheats.