CJ7 4.2 Overheating Problem

[CJ Jeeper]

Hey guys, I am stuck here! My 86 CJ7 AMC 258 i6 / 4.2l is overheating after about 3 miles. I have a new radiator, new water pump, new thermostat, the spring is still good in my lower hose.

The only thing that i am thinking it might be now is my fan shroud. there is about a 2" gap between my radiator and the shroud on the top and bottom and the round opening only goes about half way over my fan blades. the only thing is it is overheating when i am moving not just at idle. I am stuck now! I will take any and all suggestions. Cheap or Expensive fixes!

Thanks

 

[mtnwhlr]

You say it has a new waterpump. Their are two different ones and they rotate in different directions are you sure it has the right one?

 

[CJ Jeeper]

I did know that but i checked the new pump rotation to the old one and it was the same! how do i know if the old was even the right rotation though? the fan rotates in the clockwise direction when looking at the front of the car!

 

[mtnwhlr]

was it over heating so you replaced all those parts to fix it?

 

[CJ Jeeper]

yeah! I feel like i have been chasing my tail with this thing!

 

[mtnwhlr]

The difference in the pumps is wheather it has a serpentine belt or not because it spins the other direction. So when you ordered your pump did they ask you what belt system you have?

 

[CJ Jeeper]

yeah i don't have a serpentine belt. i have two separate belts one for my power steering pump and one for my alternator!

 

[Lumpy Grits]

How/what happens when it overheats?
NEVER trust OEM, Jeep gauges.
Fan should be no more that 1" from rad and YES to get'n a shrould.
When the engine is run'n. Can you feel air be'n pulled INTO the radiator from in front of the grill?
LG

 

[mtnwhlr]

So as I asked when got your new pump did they ask what kind of belt you have our did they just hand you a pump?

 

[CJ Jeeper]

MtnWhl; sorry i didn't answer you. lol, yes they did ask me when i got the new one.

Lumpy; it is a steady overheat from cold to well past hot! i don't feel and i don't feel much suction on the from of the radiator. i feel plenty of blowing on the engine side of the fan.

 

[CJ Jeeper]

these pics should shine some light on the subject. i just found a new fan shroud and ordered it. i only have the four blade fan. would you recommend a six blade fan and maybe a bigger fan spacer to get the fan closer to the radiator?

 

[mstar]

How/what happens when it overheats?
NEVER trust OEM, Jeep gauges.
Fan should be no more that 1" from rad
LG

I don't know about the rest of the guys on here,but I would not be comortable with a fan blade that close to radiator core.Lots of things move around in off road situations.I am fairly certain that is why fan shrouds were developed. mike

 

[CJ Jeeper]

you think its too close o my radiator! i was thinking its too far away. i measured it and it is 2 inches from the front of my blade to the radiator.

 

[mtnwhlr]

I'm still leaning towards wrong pump or stuck thermostat

 

[Lumpy Grits]

I don't know about the rest of the guys on here,but I would not be comortable with a fan blade that close to radiator core.Lots of things move around in off road situations.I am fairly certain that is why fan shrouds were developed. mike

OEM rad on CJ's were that close.
Mine is that close. I have a shroud and never a heat'n issue.
The only reason your rad. would take a fan hit is a bad motor or tranny mount.
OP-That fan is to far back, and you must seal around the shroud. You want a to create a 'funnel' for air flow from the front of the grill, THROUGH the radiator. You do NOT have that now.
Also-Wrong water pump is a real possibility also!
AND--Move your fuel filter away from the exhaust area-That is a known source of CJ engine fires.
LG

 

[CJ Jeeper]

good to know on the fuel filter! i am gonna install the new shroud and a bigger fan spacer and go from there!

 

[CJ Jeeper]

here is a picture of the water pump that came out. and the one that i replaced was the same rotation. can you tell if this is the right rotation by looking at it?

 

[CJ Jeeper]

sorry forgot to attach the picture! here it is!

 

[Torxhead]

I hope you are not still using the oem fan clutching unit. From what I understand it is not a clutch fan but is a fluid drive of some sort.

 

[Petescj]

OEM rad on CJ's were that close.

The only reason your rad. would take a fan hit is a bad motor or tranny mount.

Just adding that Id take a look at the grill mount bushing and the grill shell itself if it was a movement issue. The struts that position the top of the grill can also be way out of adjustment from a previous owner.