84 Jeep cj7 overheating

[Jeeper Jay]

My fuel gauge needed replacing so I replaced both fuel and temp gauge. during the process I was checking my temp sending unit and discovered it was unplugged ! I have no idea how long this has been unplugged but never had any indication of overheating plus the old gauge never went above half. After installing new gauge and sending unit the gauge moves to hot after a few minutes. Ive now replaced the Radiator,hoses,water pump,thermostat,fan clutch, and of course sending unit and gauge. Ill start it up and after about ten minutes the temp gauge shows hot. I can see water circulating when I had the cap off so I know the thermostat is opening, but it doesn't appear to be a strong flow. Plus, the bottom hose doesn't get warm. I didn't flush the block when I changed out the radiator due to the fact that the inside of the old radiator looked extremely clean, no crud. Perhaps thats my next step. Any advice ?

 

[TerryMason]

Are you able to move the fan in and out at all (try to just wiggle it around)? I'm wondering if it's a bad water pump.

You could also try running without a thermostat to make sure that you don't have the wrong temp installed.

 

[54cj3b]

when you changed your water pump ,did you compare your propeller on the new pump to the old , reason I'm asking is there is 2 type propellers one spines clock wise and other counter clock wise , I found that out when I changed the pump on a 151 iron duke in a dj

 

[Jeeper Jay]

When I bought the water pump I had the old one with me and we compared the two. But now I'm beginning to doubt what I thought was the same pump. I'm not ready just yet to take it off again. I did notice that the original thermostat had a small hole for (I think) air relief. The new one didn't have this. I'm going to yank it and check it out.

 

[Jeeper Jay]

OK, I took out the thermostat ran for 30 min no problem. Drilled a small hole on edge of thermostat (by the way it test fine -195-) re-installed. Ran and overheated. Pulled the water pump, The fins match the old one so its the correct pump.
I'm sooooooooooooooooooo confused, and tired of this particular project. HELP !

 

[SteelHeadz]

What size engine do you have?

 

[Jeeper Jay]

I have a straight six 258.

 

[Jeeper Jay]

I found the problem ! Either the new temp gauge or the sending unit is inop. I checked the block temp with a laser temp unit and its fine.........One more question, I'm starting to consider an engine swap to a chevy small block. What kind of mileage can I expect.