Yeah, well, I was actually looking for an XJ in good shape, but that was not to be. This cream puff of a WJ came along and sang the siren song. Sucked me right in! 2000 4.0 242 PA car with immaculate maintenance records and had just been detailed! NO rust anywhere, even underneath. $4000 in 2010. The really funny thing was after I gave the dealer my deposit, my ZJ didn't want to start! I should have named her "Christine!"

 

So everything checked out okay as far as I can tell. No blown head gasket or cracked head. Went ahead and put a new water pump on because the old one had some play in it. Changed out all the hoses, thermostat, etc and flushed the system.

Temp stays below the halfway mark so I think I was very fortunate.

 

Well I am bringing this back up because it is driving me crazy and have had enough. I keep having to add coolant to the reservoir about once a week because somewhere the WJ is losing it and I can't find out where the coolant is going to.

No leaks on the ground, brand new water pump, gaskets, hoses, etc. Inside does not smell like coolant when heat is run indicating a leaking heater core.

Anyone have any ideas? If it had a blown head gasket, it would not run right I would think? No obvious symptoms of a blown head gasket.

Help!

 

Okay here's what happened just recently with my WJ. After a head change and waterpump leak were done, my coolant level stayed pretty constant for a while, then started to drop very slowly AGAIN! I had been filling the reservoir up to within 2" of the top when hot because of the coolant loss and now it finally took a month for the low level warning to come on. We could not find a leak anywhere so we pressure tested the system. At 16 lbs it held constant for a long while, then started to drop ever so slightly. Shining a very bright light around the water pump area, I noticed a tiny drip from the bottom of the thermostat housing, maybe one drop every 2 minutes. At 18 lbs, the drip was faster. When we changed the thermostat housing, there was a crack in the flange thru the lower bolt hole, probably done by tightening it first and not progressively. Since then my level has only dropped 1/2" in 3 weeks. That I assume is the "allowed" weep from the water pump plus any evaporation from an unsealed reservoir.

 

So what you are saying is this could be "normal" for a WJ?

 

I'm just relaying to you what has happened to me over 80K miles with MY WJ. I've always had to add coolant over a period of time for various reasons. The longest it's ever stayed stable was about 2 months. It's only overheated once from a popped heater hose and I shut it off instantly. It was -10* and the whole front of the jeep was enveloped in steam, pretty obvious. I taped up the hose and left the cap loose, drove it home. It only got up to 240* anyway.

 

That's how this whole thing started with mine. Heater hose actually popped off at the firewall. I guess the factory clamp broke because it was no where to be found after the hose popped off and coolant went everywhere. My son shut it down as soon as the warning light came on.

Anyway, since I had to add coolant I just went ahead and flushed the whole system, put all new hoses on, replaced the water pump, thermostat/housing. Thought all was good after that. But not the case.

The only other thing I know of is the cap on the reservoir does not fit tight. It is very loose when you snap it closed. But I don't see any evidence that it is splashing out the top. However evaporation could be a possibility. But I kind of question that theory because the temps here in Georgia have cooled down and the highs during the day are in the 70's.

So...I dunno. Guess I will just keep having to add coolant every two weeks. Either that or just wire that float switch so I quit getting that stupid low coolant warning on the overhead display.

 

Okay, when the cap releases pressure in the system, coolant at engine temperature flows into the reservoir. There's where the evaporation happens. To eliminate the warning, all you have to do is pull the plug on the float switch, but then you won't get a warning until air gets into the system and the temp rises.

 

I am also having this problem. I was loosing coolant and having the low coolant light come on and my heat wasn't as strong. I took it into my class to check to see if it was a head gasket. No hydrocarbons were found with the radiator open using a sniffer. After that was done I topped off the coolant and for a few weeks it was fine. Couple weeks later I got the heater core flushed. Same thing happened low coolant topped it off and was fine for a couple of weeks. No visual signs of leakage.

I also have the 2002 GC Laredo.

 

did you try to just replace your rad cap first?

 

I sent it off to the mechanic he said it was just the radiator cap. I didn't catch it either until I saw it. The coolant was evaporating through. We will see if it stays filled up.

 

Update about a week and a half later the light is back... Any suggestions?

 

One thing I just discovered and posted on another thread was I noticed a slight coolant smell and got down on the wet road with my 600 lumen flashlight and noticed a wetness on the bottom of the passenger's side radiator tank. I took it to my mechanic the next day for a radiator. After removing the fan and shroud, we saw some white corrosion on all 4 corners of the radiator fins where they are welded into the tank flanges, one of which was wet. It was obvious to me it had been leaking enough to steam out and evaporate without dripping, for a long time!

Since the radiator change, my coolant tank level is stable, only changing with temperature, like it's supposed to!

BTW, it was 16*F out when this happened and I got a nothing-fancy OE replacement from a local vendor for $121.88. The back of my jacket is stained with road salt now. The original one had 205K miles on it.

 

I'm gonna put it on the lift Thursday and pressure test the system as well. I took it to a mechanic and he blew the parts cannon and said I needed a radiator, thermostat, water pump etc.... I think the water pump might be the culprit. I went to top it off yesterday and my belt looked like it was starting to crack... Its hard to track down because I can constantly smell coolant when I'm outside it but once I open the hood there are no leaks that I can see.

 

Okay, new thing. My WJ started using a lot of coolant AGAIN and there was a smell of coolant that I couldn't track down. In the morning, I looked at it again and saw coolant on the exhaust manifold for #1 cylinder. The mounting stud had built up crystals on the nut and rust had started to form on the manifold itself. WTF!! Then I thought about it a while. That head bolt on the front corner is threaded into the water jacket and needs sealant on the threads when you install it. They forgot to use the sealant when they did the head change! That exhaust manifold stud is threaded into the head bolt clearance hole so the coolant was leaking at the block surface and coming up and out thru the stud threads. When it's running, it's hot enough to steam off and look dry, but after it cools, it shows up as liquid. Son of a B****! Someday I'll get this thing to not leak, I swear!

I'm not mad enough yet to take my .44 to it, but I'm close!

SO... new radiator, thermostat housing, hoses, new water pump in the last 6 months, and a sealed head bolt. Let's see what happens now!