Well I've had both issues. But using the ac makes the overheating issue worse so I kind of included it. And no. After everything I did it still overheated in summertime. But at least with the clutch fan, when it starts creeping above 210 I can put it in neutral and run it up to about 3000rpm and cool it down that way.

 

So I'm gonna be that guy who re-hashes a post from over a year ago, but it's at least a thread I started about my truck specifically.

Anyway, Jeeperdon was correct in my other post, I know some of you commented on that one as well, the one about the Griffin aluminum radiator I put in my Durango. Well when it's up around 95° outside with the sun beating down, the truck will barely stay at 210° with a 180° thermostat and the Taurus fan on high speed with a 12" flex-a-lite pusher fan in front of the condenser on as well as the A/C being on. A/C is also fixed. It was a rear expansion valve that was the issue. With this radiator it shouldn't struggle this much to stay cool. When I get on the highway, the temp will climb. If I let it settle out at 65-70 going downhill it'll be okay, but flat or up hill it'll overheat, even at that speed. If I get off the highway and sit at a stoplight, the temp will come back down to right around the 210° mark. So in the safe zone, but still hotter than it should be.

Check list:
1. Thermostat, 4th one in the truck, still overheating. I know it's opening.

2. Water pump. Had upper hose and thermostat out and started the engine for a second with water up to the top of the radiator. Water came out of the thermostat outlet like it was going out of style so the water pump works.

3. Pressure. Hoses have pressure when the truck gets to operating temp. I have a temperature switch in the upper radiator hose that allows me to fully bleed the system (it's at the highest point in the system) so the system is bled properly.

4. The heater core. I have good heat in the cab, it's never seemed to have a bubbles caught in the core. I know that's a common issue in these, but I've never had bad heat so I don't think that's it.

5. Radiator. Well, obviously that's been replaced with a much better one. Regardless, I am able to see coolant flowing through all the little tubes in the radiator.

6. Head Gasket. I bought a chemical block tester. Got the truck up to operating temperature and used the block tester. Did it for 30 minutes and still no signs of a blown H/G. Tested the "block tester" by putting it near the exhaust with the truck running and the fluid immediately turned yellow so I know it works.

Now for the reason for this post. I did plugs wires cap and rotor last night. It had Bosch platinums in it. Which I know is a no-no but the previous owner apparently didnt. It's got Autolite 5224 copper cores in it now. But, the reason that sparked this (no pun intended) was to look for a lean condition causing my overheating issue. Well, 1,5,7 are all lean. So my question, do you guys think that's enough to cause this issue? And if so, my first guess would be injectors but wanted to know what you all thought.

P.S, I did the Kegger Mod and hughes plenum to this truck.

Here's some pics

#7 is as bad as 5 but I took the picture from the wrong side, got the tip of the plug a little dirty pulling it out.



The stand alone picture is an up close of #1.



I know running lean creates excess heat, but are 3 out of 8 cylinders enough to cause this issue? They are pretty lean, I must admit. Very white and powdery looking.

 

Have you done a compression test yet?

 

I haven't. Not questioning you or anything, just curious, what would be the reason for one? Is it to test for a blown H/G or a leak through the valves or rings?

 

All of the above.

I know that when I am chasing mechanical engine problems I like to do it just to rule anything out. A couple low cylinders may not be felt but will definitely make the engine work harder to get things done.

 

Still sounds like it could be air stuck. Wonder if you got one of those vacuum things to fill it with of that would help.

 

I can check those out. I'll try to bleed more air out of the system if I can through the upper hose now that it's had a few heat cycles. But the hoses are really hard so if there is air I would guess it's not in the hose. All of what's happening still revolves around the original issue of, it only overheats after about 30 minutes of driving.

 

And what's the deal with those plugs? These motors really don't like anything other than plain coppers. Maybe that's part of the issue.

 

Yeah I know. Previous owner kind of thing. Auto lite copper cores are in it now. Idles smoother and has a little more power now. Not a huge gain, but I noticed it. Was gonna run them for a while then pull at minimum 1,5,7 and see if it's still lean on those cylinders, I think it will be though.

 

How many O2 sensors on that engine? Do you have a pre-cat sensor for each bank?