jgstang

97 jeep grand cherokee 5.2 is running hot... i have done recently a new radiator,water pump,195 thermo,all hoses,fan clutch,cap! it all started a month ago when i was sitting in line at arbys, a lady walked by and said that your loosing coolant... so i took off and pulled over 3 min later and the lower hose just popped off! the gauge read alittle over half as i turned it off! had it towed home. i pulled the radiator and it was fine, got a new clamp and that fixed that... but now the car runs hot like beteen 1/2 to 3/4 or more if let it, i burped the system and still runs the same... burped it again today but today when it was running with cap off the coolant was just shooting out the top! so i went to town with the car after letting it cool down for 40 min i filled it and drove it, it got to the mark after half and creeped to 3/4 but when going down hill it dropped to almost half! so i picked up that bars HG-1 for it. oh about 2 weeks ago i pressure tested it to 20lbs and it help for a long time with the hoses rock hard!! when i pulled the radiator i did clean out all the fins on the ac condensor to make sure for good air flow. when it idleing if i put a rag in front of the radiator it pulls it to the grill so its getting air ? when stopped at a light i need to put it in nutrual and rev it to 1200 to cool it down. it takes about a good 25-30min to get that hot! i'm thinking on useing the bars in and getting a universal 2 row 1" tube radiator i think ? any thoughts.... no white smoke, no water in the oil and and no rough idle at start up. thanks

jgstang

so i just went out there to try this again, system full of coolant. pulled off cap and set a 2 liter bottle over radiator with bottom cut of to see if it just blow out just bubbles! when the thermo opened boy it shot out the bottle and melted it to some degree..but its not overheating in the sense of boiling over, stop and go traffic at 100 plus temp it will go to 3/4 maybe alittle higher and after going again it will come back down to just above 210 most of the time, upper hose is rock hard! i will check coolant after cooled down and maybe add a cup ? sound like a blown HG ? i have not tried the bars HG-1 yet. if it had a blown HG it wouldn't cool down at all would it ? not boiling over or here it boiling, and like the first post all is replaced ? if you have any ideas please let me know. thanks Jim

GCWJ

The thermostat is new, but does that mean it still can't be bad?

I really got nothing else. Others probably have different and better ideas.

dave1123

Bubbling when the coolant is cold is a sure sign of a HG leak. To be sure, you should test it for exhaust gasses with a tester that goes on the rad cap. Keep in mind that coolant with no pressure boils at just over 212* whereas at 18 lbs, it'll boil at 260*. Also, steam pressure expands exponentially when it boils and can blow off hoses and split radiators. That's why the cap is designed to release at overpressure and vent to the reservoir.

As I said, use the tester. The liquid in it will turn colors if there is exhaust gasses present. I've had bad luck using any stop-leak stuff because it can clog heater cores and radiators.

Just my opinion.

rangermonroe

Ha... another 5.2 running hot.

Anyone else noticing this... again?

JGstang.... I have been dealing with the same problem for a year. I have replaced my cooling system, entirely. All of the things.

Weekly here, there is a new thread just like you posted. Every. Week.

Guys just like you and me, "the car is overheating a little, not enough to deadline, but just enough to be concerning".

Every Week.

I have no idea how to fix this, other than to turn off the A/C when stationary. If I manage to figure this out, (and I am trying, everything) I will post here and be a hero to all.