EAGLE help OVERHEATING

Howdy Eagle and all other peeps, my crew from Jeepz/com sent me over here to ask y'all about this overheating prob

probs w/my 89 Cherokee
Its overheating at idle sitting in the driveway
This weekend I replaced the
fan clutch
thermostat
radiator
both hoses upper and lower
replaced the water pump too

the fill/expansion tank was new when I bought it

STILL overheats --any suggestions????

1. did you use a dealer thermostat with that little hole and a bb in it?
2. if not dealer thermostat what is the temp value for it?
3. did you burp the beast?
4. make sure you got the right fan clutch (as in it has the blades bent in the right direction so that it pulls the air in instead of pushing it back out at the radiator... and don't ask how I know).

Kejtar said:

1. did you use a dealer thermostat with that little hole and a bb in it?
2. if not dealer thermostat what is the temp value for it?
3. did you burp the beast?
4. make sure you got the right fan clutch (as in it has the blades bent in the right direction so that it pulls the air in instead of pushing it back out at the radiator... and don't ask how I know).

Click to expand...

well it was aftermarket thermo, but did have the little hole
did burp it
fan clutch is the only one available and put the blades on the clutch w/the stamp that says FRONT pointing towards the radiator

On a side note

it overheats w/o the thermo in at all

Welcome. If you do a search, you're going to find tons of reasons why your XJ might be overheating.
Here's an often-overlooked item: Most of the engine heat dissipates not through the radiator cooling system, but through the exhaust. Make sure your exhaust isn’t clogged.
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My wife sometimes wishes that mine was...
assgas:

That little hole in the tstat, what postion on the clock is it facing ??
So, the pressure bottle and the cap were new when you bought it, have you owned it since new ?? might be time to replace it, they crack and won't hold pressure as well as the cap going bad. I will also mention that it is NOT an expansion tank per say, it's a pressure tank and the cap is a pressure cap, if it will not hold pressure it will overheat.

RTicUL8 said:

Welcome. If you do a search, you're going to find tons of reasons why your XJ might be overheating.
Here's an often-overlooked item: Most of the engine heat dissipates not through the radiator cooling system, but through the exhaust. Make sure your exhaust isn’t clogged.
===
My wife sometimes wishes that mine was...
assgas:

Click to expand...

Mine solved that problem assgas: by controlling my diet

RichP said:

That little hole in the tstat, what postion on the clock is it facing ??
So, the pressure bottle and the cap were new when you bought it, have you owned it since new ?? might be time to replace it, they crack and won't hold pressure as well as the cap going bad. I will also mention that it is NOT an expansion tank per say, it's a pressure tank and the cap is a pressure cap, if it will not hold pressure it will overheat.

Click to expand...

Rich,

The jeep was bought in January and has been a great little vehicle so far. The pressure tank was replaced b/fore I bought the vehicle (in Dec) but I dont know about the cap. I bought a new one today, will try it when I get home. On the exhaust, I thought about that too, but the converter back was replaced back in Dec (right before I bought it).

How exactly would i verify that the exhaust is not actually clogged? Just wondering because my engine is running hot....210-220 and the radiator is looking good on coils. I'm no expert, any help greatly appreciated.

siminsez01 said:

How exactly would i verify that the exhaust is not actually clogged? Just wondering because my engine is running hot....210-220 and the radiator is looking good on coils. I'm no expert, any help greatly appreciated.

Click to expand...

210 to 220 is not hot -- it's normal.

kcash1 --

Looks like you replaced everything that should be replaced, now the question is if they were replaced with the correct parts. RichP has a good point on the pressure bottle. If it won't hold pressure, the engine will overheat. Most folks find that replacing just the cap alone or the bottle alone doesn't work -- it seems they need to be replaced together, as an assembly. Quadratec sells them for $19 new, so that might be worth a try.

I don't happen to like plastic, so I went with an all aluminum pressure tank from Moroso. But that's a bunch more money, and I would not suggest it without knowing it's going to solve your problem.

What radiator did you install, and are you cerrain it's flowing to full capacity? There have been reports, for example, of GDI radiators arriving with debris blocking some of the tubes.

What thermostat did you use? I was surprised to read that you found an aftermarket t-stat with the bleeder hole, because I look when I'm in the parts stores and I have never found one. Yes, I see thermostats with a bleeder check valve -- but they aren't listed for the XJ, and the units from the same manufacturer that they list for the XJ don't have the check valve.

How's the fluid level in the pressure bottle? It should be filled to the halfway mark when cold. If it's overfilled, the coolant can't expand without forcing some out. If it's underfilled, you don't get full flow through the system.

Have you verified that it is overheating (i.e. is it boiling over), or is it possible that you have a faulty gauge or sending unit?

How's your water pump? Is it the right rotation? It's the same fit as the 258 4.2L engine in the early YJ, but the impeller rotates the other way. It should look like:


The rest of the suggestions in this thread seem right on...

Edited to add:
Is your aux fan working? After replacing most of my front-end cooling junk a few weeks ago I managed to leave the fan disconnected. Everything was fine while cruising up I-25 until I hit construction at around 10pm and had to stop....temps jumped too high so I had to crank the heater and put the windows down to cool off. If you want, you can drop a newer cooling fan in there, they flow more air and that should help as well.

Throw in my two cents worth. The universal gasket, for a thermostat, blocks the outlet to the surge tank (pressure tank/heater etc.). Have to use an OEM, OEM type or cut some of the universal gasket away, so the system flows correctly.

allright gang, the $6 cap fixed the damn problem, it wasnt holding pressure but at least now I have a completely rebuilt cooling sys that's not a bad thing down here in TEXAS its only 103 today
HAHAHA

thank you all for your help