fabian9931

Quick story....

2000 XJ 4.0, Auto 160k miles
-No heat then overheated
-Original Thermostat So I changed it.
-Original Waterpump So I changed it.

After repairs, During idle...
-Top hose hot.
-Lower hose cold.
-Heater core hoses both cold.
-Fan kick on and works.
Tried to burp it and air it out as we know jeeps are a pain the *** to air out. Ran it for 20 min sections about 3 times. Total of 1 hour.
Same symptoms with top hose hot, lower hose and heater core hoses cold too.
Seems like there is a blockage of some sort, but Radiator is not blocked as I flushed it no problem when I took the radiator out of the car to flush with a water hose.
Still getting cold heat.

Thinking head gasket, but would a head gasket cause lower hose to be cold? Im ready to pull the head out. My main question is i know the head gasket on these are easy to get damaged but i want to make sure it is before i pull the head. Right now its snowing here and its sunday and no parts store are open. I wanted to buy one of those turkey basters head gasket emissions tester to test for it. is this a good idea?

if anyone searches and finds this thread and is looking on how to pull the head out and details instructions. I have Mitchel on demand and here is the details instructions on how to pull head out. if anyone needs to.

fabian9931

Here is more for the install... #11 gets 100 lbs of torque only!

claygrassmann

Should def make those instructions a sticky. But i doubt its your head gasket. Try flushing the heter core and see what that does

tntchitwood

You said you flushed the radiator, what about the engine and the heater core. A lot of times PO's will use radiator stop leak and over do it stopping everything up. Good luck, keep us posted.

EDIT: I also doubt it is your head or head gasket either. Do you have water in your oil?

fabian9931

Forgot to mention, silly me. ONLY, after i shut it down. I heard a popping coming from the lower hose, litterally lower hose. and i smelt oil in the coolant funnel I used (yellow funnel).

But why flush the heater core if it doesnt even get that far yet? Not like one hose on the heater core is hot and the other cold. But both are cold.

Forgot to mention also... yes i did flush the engine. had the water hose (from house) watering engine where thermostat was and had car running with lower hose detached. let it flush that way. then other way around. water into pump hole and had car running as well.

Dip stick is normal. But funnel looks like it could be mixed. its a tricky one. cant say it is oil cant say its not, its tricking me big time. I never used radiator leak before. This past summer I did have that muddy rusty thick gritty stuff in my radiator I guess from the build up, Thats why i flushed it. Even took out the resevoir and washed that with boiling water to get the stains out. I personally sometimes think that its not a headgasket and just a bad air pocket because those other hoses are still cold! but im no master tech but i have some what mechanically inclined lol

Beat-up Sport

if you had red/purple sediment/sludge in your system, somebody put stop leak in it.

fabian9931

is that considered that rusti gritty sandy stuff? if so then i guess so but it wasnt me and im the original owner

tjwalker

You have a 2000, which came from the factory with the "infamous" 0331 head, which has a casting defect between cylinders 3-4.

Overheating makes this head EXTREMELY prone to cracking.

Your cooling system should burp itself with about 3, maybe 4 complete cycles of heat up and coold own.

The fact that you had an overheat and are now having these symptoms does make the head suspect here.

The #1 clue for a cracked 0331 head is coolant loss. Are you losing coolant from the reservoir?

Many can see the crack by shining a good light down through the oil filler hole, or by removing the valve cover gasket. Other tests include the "block test", cooling system pressure test, compression test, and the comprehensive cylinder leakdown test.

fabian9931

yes i know this as i posted the info on the "tip picture" above. but i cant check for coolant leak or coolant missing right now because the resevoir is empty due to me taking it apart and cleaning it the other day. so yea thats empty. right now im trying to burp the car and i would say im on cycle 3 as i just finished that literally 5 min ago. ran it for about 20 min, fan kicks on. coolant in yellow funnel attached to radiator bubbling and burping. still same symptoms hot top hose cold lower and cold both heater core hoses. i didnt let it over heat i just shut it down after 20 min of running it but the weird thing that throws me off is there is a popping noise, pop pop pop pop pop in the lower hose or maybe in the waterpump to lower hose area. with car off it only pops and it still burps and bubbles and the coolant seems to raise in the yellow funnel. not sure if coolant is dirty or if its got oil but dip stick is clean, but fluid in funnel does look like oil. but cant say for sure. I just dont want to do the head gasket and then have the same problem. here is a pic i have taken of the fluid in the coolant yellow funnel i am talking about. maybe you can see better than me. maybe my brain doesnt want to say yes its oil. i dont know, but if its the head gasket ill have this ripped apart tomorrow. got 16 inches of snow out and car in garage and thats it.

BUT. would a head gasket or cracked head make the lower hose and heater core hoses cold????????? that throws me a curve ball because to me as i stated before im no master tech but to me if all hoses were hot and it was flowing and still overheated then i would assume head gasket.

Black00XJ

Pull the plugs and do a compression test. Fastest way to determine head gasket problems

fabian9931

gonna pull the plugs and do the compression test tomorrow evening. during the day i will try to burp it one more time

fabian9931

ok update: tried to bleed it more. 2 more times. but before the last time i removed the front headlights grill and center grill to access radiator more freely. ran car for 10 min to get it to regular operating temperature again as stated top hose hot. lower cold. and heater core hoses cold too... so picture viewing the car from the front. the top radiator hose is on the top left corner and the lower is on the bottom right. the top left area of the radiator is hot, but the lower left corner is cold. also cold is the whole bottom of the radiator plus the whole right side area were the lower radiator hose is too. even the radiator cap neck is cold. only hot part is where the top hose connects and about maybe 3 inches down, then gets cooler. shouldnt it be somewhat all hot? sounds like a clogged radiator?

fabian9931

another update. changed radiator. it was clogged but not 100% did let some circulation through but not enough. now with new radiator installed i get this...

both upper and lower hoses get hot. heater core hoses get hot too. car doesnt overheat. heat blows alittle more than warm, enough to shut me up and deal with it. took it for a 5 min ride. heat ended getting cold. pulled it into my garage and heater core hoses were cold and also radiator hoses. ended up blowing and water flushing the heater core and heater core hoses. same thing. so also when i was burping the car the yellow radiator funnel always bubbled, never stopped and stayed steady. it was smoking from there too, but must be from it being 25 degrees out and my garage door was open. i will buy a block tester tomorrow morning and test it. what do you guys think

mcssls

sounds like a major blockage in the block. Old radiator was plugged due to whatever plugged the block up. How long have you had it? I would wonder if the PO put that stuff in that is supposed to fix a blown head gasket without tear down. That would be like a bucket of bars leak. If so your block may need tear down and tanked to get it cleaned out.

fabian9931

my father in law is the original owner then handed it to my wife which now i use it. so we took it over back when it had 60k, now it has 160k. that gritty gunky rusty stuff must've blocked up the radiator. tomorrow morning first thing im going to get a block tester and see if exhause fumes are getting into the coolant system. if so then im going to do the head gasket if it passes i have no idea what to do