pineapple_tree

Thank you for that Dusty.

Okay. So I didn't know that the 2.5 fan clutch is the same as the standard duty ZJ 4.0 clutch, which makes a whole lot of sense because my co-workers say I sound like a dump truck trying to get up the hill to my work.

I think my main problem is rust here, as far as it's in the cooling system.

So, about 2 months into having this Jeep, I tried to take the radiator cap off to hook a pressure tester to it, to find a leak. That cap wouldn't come off. I mean I took vice grips, hammer and chisels, and even an air hammer to beat at the side of it to break it loose. No dice. It was clamped shut. So, I did what any logical human being would do, and that was to take a grinder and cut off the ears of the cap, and just take the top of the cap off without it being locked on the radiator. When I did manage to get it off, I was greeted with 100% rust water. It wasn't rust-colored, it was chunks of rust and about a 1/4 inch of rust lined all around the radiator cap. So, I got a new cap and got a new thermostat, water pump, upper and lower hoses, coolant, and a water hose. I tried to clean out all the rust I could, but I think most of it got stuck in my radiator. I then filled it up with 60/40 bright green coolant that I diluted myself, and I was on my way.

Now, 3ish months later, that same green coolant that was as bright as green grass, was now orange and sad-looking. I discovered that when I pressure tested my system again and found a leak at the radiator.

So, I'm going to get a new radiator from Autozone. They have one, but I have to wait 4 days to get it. Not a big deal. But, this is what I'm going to do.

I'm going to flush every single line with water, and then I'm going to take each line off and wash it in a cleaner solution that doesn't mess up rubber. I'm then going to flush it again, and clean everything again, then run water through it until it's warmed up, drain it, (out of the block too), flush the lines again, clean the hoses again, and then I'll put a new radiator in it. Then, I'll fill it up with coolant, 60/40 mixture for the summer, and wait about a month and then flush it all over again and re-fill it back up. I'm also going to get a new overflow tank since I'm pretty sure mine is clogged up with rust.

Sometime down the road, I'm going to add a cooling fan to the front that pulls air in past the condenser and radiator and keep the clutch fan in the rear. I'll probably have a switch to run it on high whenever it gets too hot out, and that way I don't have to spend a lot of extra time adding a stock cooling fan and getting it to come on at different speeds and temps.

Veeb0rg

You should also run a coolant system cleaner through it as well, preferably one that neutralizes rust if it is as bad as you say.

lawsoncl

So the system is rusted up and wasn't holding pressure. Yup that explains the overheating and it was probably boiling due to lack of pressure. I'm willing to bet someone filled it with water, or that's the original coolant.

Use a good flush, maybe a couple of times and then replace the radiator. Avoid the acid-type flushes which might cause a heater core leak. If the hoses and pump are old, just replace them. I wouldn't bother trying to clean them inside. If you have that much rust, the impeller on the pump is likely eroded away as well. I suspect your heater core is plugged up as well, so I would flush that back and forth until it runs clean as well. If you have that stupid heater control valve on a 2.5l, now would be a good time to eliminate it. If your fan "sounds like a school bus at startup", then it's probably just fine and an aux fan probably isn't needed either. Neither do much at highway speeds compared to forced air anyway. Most of the guys upgrading the fan clutch are doing a lot of slow speed idling offroad and need the extra air flow.

pineapple_tree

Well, I don’t think i’ve eaten away at my water pump impeller just yet. I replaced it maybe 3 months ago, and the old one was 2 years old and it wasn’t in that great of shape.

I also did back flush the heater core and bypassed the heater control valve, and I replaced the lower and upper radiator hoses.

Regardless, I got a radiator from Autozone. It was $140, and it’s an all aluminum radiator too, which is awesome. I plan on flushing everything multiple times, as well as run some good cleaner through it. I’m hoping to get most of the rust out by replacing the radiator, and then flush the rest out through the block.

pineapple_tree

Well, the new radiator fit somewhat. The bolt holes were 3 times smaller than OE, and I couldn’t find any bolts to fit it. So I improvised with some zip ties for the time being.

I also flushed the crap out of my system. I mean the amount of rust that came out of this thing was unreal. I spent an hour flushing everything, including the heater core. I backflushed that first, then flushed it the other way, and did that back and forth until clear water came out after switching back and forth. Flushing through the thermostat was nasty as crap, and so was flushing the overflow tank. That took the longest with how much crap came out of that thing. But I filled it up, bled it, and ran the heat and noticed that my heat was 100% better than it ever was, and the radiator actually held heat this time around.

All seems good for now. Plus that all aluminum radiator looks pretty sweet and sleek

Rogue4x4

So basic maintenance and stock replacement parts are all it took, who'd of thunk it

pineapple_tree

And don’t forget the 20 something gallons of water that it took to flush out years of neglect

cruiser54

Those zip ties are gonna fail......

Rogue4x4

A flush IS basic maintenance

Rogue4x4

Agreed, get the right hardware in there STAT

cruiser54

Then we'll have another thread. " My new radiator fell into my fan!"

Rogue4x4

Red1992XJ

Carnac- "Sss- boom-bahhhh."
Ed- "Sss- boom-bahhhh."
Carnac- "What kind of sound does an exploding sheep make?"

Rogue4x4

May an unclean yak have an accident on your toupee

DustyWagoneer

May the fleas of a thousand camels, infest your Hi-Poo 2.5L