Oly Posted February 7, 2014 Share Posted February 7, 2014 ok so 88 mj 2.5l. overheated a month ago changed thermostat and she has been doin fine. i have a small leak from my radiator and i don't make much money so ive been adding water. about a week ago was the last time i added water. this morning it started snowing so its pretty cold started the truckshe was doing fine let her warm up drove 3 miles and she started overheating. so i pulled the thermostat on the side of the road. hooked evrything back up and drove to work bout another 2 miles and she was boiling over when i got there. had to be towed home tonight because she just keeps overheating. i popped the cap off and rann it and it seems to be cycling water......please tell me this isnt a blown head gasket. I'm in need of help I'm beginning to lose my passion for the mj Link to comment Share on other sites More sharing options...
Blaine Posted February 7, 2014 Share Posted February 7, 2014 if the w-pump is cycling water with no thermostat then it does sound like a head gasket is gone, if u hadn't of said the water is cycling i would have thought u cold have frozen you w-pump by adding water to it. Link to comment Share on other sites More sharing options...
Blaine Posted February 7, 2014 Share Posted February 7, 2014 I'm not familiar with the 2.5 but this link is too a thread were someone could help you out more http://comancheclub.com/topic/41577-overheating-question/?hl=overheating Link to comment Share on other sites More sharing options...
Oly Posted February 7, 2014 Author Share Posted February 7, 2014 i was afraid of hearing that. while at work today it took bout 10-15 min for it to start boiling. do u think i should replace water pump first or rip of the head? Link to comment Share on other sites More sharing options...
Jeep Driver Posted February 7, 2014 Share Posted February 7, 2014 You are below freezing there? yes? Never add just water when it is below freezing.........something broke........bad. Link to comment Share on other sites More sharing options...
benjy_26 Posted February 7, 2014 Share Posted February 7, 2014 How's the oil look? Link to comment Share on other sites More sharing options...
Oly Posted February 7, 2014 Author Share Posted February 7, 2014 oil seems fine. so i just went out to put antifreeze in it so i don't mess up the block over night. i put probably 2 cups of straight antifreeze in the radiator to fill it up. started it and it wasnt cycling well. the water was brown-ish and i ran it till it started getting hot and there was still plenty green that i could see so i don't think its cycling what do u guys think? Link to comment Share on other sites More sharing options...
Blaine Posted February 7, 2014 Share Posted February 7, 2014 i would make sure coolant is full, if its a closed system pull the hose going into the top of the radiator off, keep the other end hooked to the goosneck on the engine, have a friend start your truck while you r holding the hose (obv. away from yourself) and if coolant start gushing out your water pump is working. with my 4.0 i was constantly having overheating issues, removed the t-stat helped for a bit, but after awhile my truck wouldnt even idle without overheating, i was running water bec, i wasn't about to by coolant every time it spilled over. replaced the gasket and used a spare head i had bec mine had major rust in the spots where the water was blowing by the gasket. but like i said I'm not familiar with the 2.5 the link in my last post is a thread about a 2.5 overheating issues. ask someone in there they might be able to give you more specific advice. good luck and hopefully its not the head and something simple Link to comment Share on other sites More sharing options...
Blaine Posted February 7, 2014 Share Posted February 7, 2014 brown is a sign i a needed flush. def. will help Link to comment Share on other sites More sharing options...
Oly Posted February 7, 2014 Author Share Posted February 7, 2014 ya i know she needs a flush. i don't mean to sound like an idiot I'm actually very knowledgable with cars but i get paranoid evrytime its my vehicle having the issue lol. I'm thinking its a water pump cuz yesterday she was purring like a kitten and i didnt romp on it or anything. now shes overheating. I'm thinking it got too cold last night and this morning when i started it maybe it sheared the water pump? Link to comment Share on other sites More sharing options...
Jeep Driver Posted February 7, 2014 Share Posted February 7, 2014 If you are not seeing any movement of the coolant with no thermostat........I would start with the water pump. I suppose its possible that water froze in the pump and it got damaged. Link to comment Share on other sites More sharing options...
Jeep Driver Posted February 7, 2014 Share Posted February 7, 2014 ya i know she needs a flush. i don't mean to sound like an idiot I'm actually very knowledgable with cars but i get paranoid evrytime its my vehicle having the issue lol. I'm thinking its a water pump cuz yesterday she was purring like a kitten and i didnt romp on it or anything. now shes overheating. I'm thinking it got too cold last night and this morning when i started it maybe it sheared the water pump? We posted at the same time..........yes.......that's what I'm thinking. Link to comment Share on other sites More sharing options...
Jeep Driver Posted February 7, 2014 Share Posted February 7, 2014 There is another member here with a 2.5 that lives near you, he lost his head about 6 weeks ago do to freezing. Link to comment Share on other sites More sharing options...
Jeep Driver Posted February 7, 2014 Share Posted February 7, 2014 http://comancheclub.com/topic/41263-prestone-warning-plz-read/ Link to comment Share on other sites More sharing options...
Blaine Posted February 7, 2014 Share Posted February 7, 2014 i got lucky i have a whole spare engine (hence where my head come from) the only reason i replaced my head was bec. 1 of the rust it had gotten from water 2. it overheated so bad i had steam come out of every orifice and i was watching my vale cover gasket melt. didnt want to take a chance on a warped or cracked head. seeing i didnt have the resources to have it checked Link to comment Share on other sites More sharing options...
yxmj Posted February 7, 2014 Share Posted February 7, 2014 I think your likely candidate is your water pump Here is what a good new pump vane looks like. I bought a cherry 2000 XJ for $700 a while back…..the fellows mechanic had diagnosed (or misdiagnosed) it to have a blown head gasket…….Problem turned out to be the high mineral content of the water he was running in the coolant…..It had rotted the vane away to a Japanese throwing star….might not look bad from the top but check out that side shot…. You can also remove and test your thermostat easy…pull it out it is only 2 bolts look at it…..a stuck open stat will be clearly STUCK OPEN…a lot of people just use a pot of water on the stove ( a cooking thermometer helps) ….put the stat in the pot of water and set to high water boils at 212…your stat should obviously be closed at first and as the temp gets to 190-195 should open. A faster quicker way an old timer showed me is pull the stat…..if you can see it is not stuck open lightly run your lighter or a torch over the copper/brass colored ball…..the heat will open it....Good luck . :MJ 1: . Link to comment Share on other sites More sharing options...
Blue88Comanche Posted February 7, 2014 Share Posted February 7, 2014 This PDF should help some: General Cooling System Servise It covers draining, cleaning, flushing, and refilling the cooling system. It also covers testing the thermostat. Link to comment Share on other sites More sharing options...
Oly Posted February 7, 2014 Author Share Posted February 7, 2014 thanks for the replies guys youve been a big help. its cold again this morning I'm gonna go fire it off and time how long it takes to get hot. i was told if its a blown head gasket i should see bubbles/air pockets coming up through the radiator. would you agree with this? Link to comment Share on other sites More sharing options...
yxmj Posted February 7, 2014 Share Posted February 7, 2014 Yes and no....the XJ i described above had that happening.....bubbling up in the rad or with the cap on the reservoir bottle.....that was purely caused by the overheating due to lack of water pump. If your head gasket was gone it would empty the fluid by sucking it into the motor.....it would run crappy.. your oil would appear yellowy or muddy.......you would have a more noticeable exhaust fume.......and when it over heated it would be because it is dry from all the fluid going into the motor..... Is you motor right dry when it overheats??? if the answer is yes....go for the head gasket....if no......go thermostat ? water pump........ Put it this way...... it is 2 bolts and about 15 min to check/change a thermostat.....it is about 12 bolts and 45 minutes to check and change a water pump.......you have to remove the entire top end Accessories/Head/Manifolds and about 6-8 hours to change a head gasket........(if you have the tools and skill set) Start with the water pump......I would bet $$$$ that is the problem.....try testing it by taking off the hose that goes to the heater core when the motor is running....you should get a crazy stream of water....if not........................ Link to comment Share on other sites More sharing options...
Oly Posted February 7, 2014 Author Share Posted February 7, 2014 so i just went out there to start it and now its cycling and not overheating. i think the water froze in the bottom hose and wasnt allowing it to cycle. and last night when i put antifreeze in it it must have melted that ice and now its cycling thats the only thing i can think of tho. Link to comment Share on other sites More sharing options...
yxmj Posted February 7, 2014 Share Posted February 7, 2014 Good stuff....get a tesyer and make sure your anti freeze is up to snuff......or drain it and refill it with good new stuff. . :MJ 1: . Link to comment Share on other sites More sharing options...
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