I changed the water pump, tstat fan belts, had the head done and the radiator flushed and tested.
What else could it be. THe stupid thing is still over heating.
New shroud and new fan/clutch Sorry left that out
EDITED TO INCLUDE MORE INFO:
Hi All,
I decided to clean this post up and be a little clearer on what has been done to the heap to this point.
Truck seemed to be running fin when I first bought it. But it was cooler in Jan.
I did the basics:
Plugs
Wirers
Oil/filter
Air filter
{Shock,Brakes,Tirers/rims} Yes no affect on cooling I know, just part of the list
Flushed the coolant (block and radiator ) with Prestone kit.
Hoses checked ok
Changed out tstat
Clutch fan
Flushed and pressure tested radiator
No coolant in oil
New water pump
Another new tstat
New belt
Pulled the fuel tank and replace bad hose to fuel pump
New radiator cap (x2)
Pulled head and had it rebuild and resurfaced Put in new seals, gaskets etc.
new fan shroud
Some of this I did some the mechanic did so I am going to check his work when it gets home.
The point of coolant is to raise the boiling point (or lower the freezing point) of the mixture. Water boils at 212*. If you have a 195* t-stat, you're cutting it kind of close.
This chart needs to be corrected to PSIG. 0 PSIG would be 14.69#'s. 10 pounds of additional pressure above atomospherric would make the boiling point of straight water 238*. My cap says 14# which would be 246*. Nothing for nothing but to the OP. You did replace the cap on the rad right? Also I've heard of running food grade citric acid thru the cooling system to dissolve mineral build up. I think the guy ran stuff that you used to clean your dishwasher with. Just a drunken thought.................
Well I ran the test yesterday and the fluid did not change form blue to green so I am guessing by the direction I do not have a crack in the block or a bad head gasket.
This is really weird. At least if i had a crack int he block i would know where to go from here. Still no idea...:dunno: :brickwall
I have skimmed over your thread and may have missed this but did you replace the radiator? If not here's a simple test to see if it is functioning properly. Get this engine hot again. Shut the engine off and then with you hand (be careful!) feel the center of the radiator core it will be very hot. Now check the four corners of the radiator core. They should be just as hot. If they are not then the outer sections of you radiator core are clogged. Don't waste your time with any type cleaner buy a new stock unit if the radiator fails the 'feel test' I just described.
I have skimmed over your thread and may have missed this but did you replace the radiator? If not here's a simple test to see if it is functioning properly. Get this engine hot again. Shut the engine off and then with you hand (be careful!) feel the center of the radiator core it will be very hot. Now check the four corners of the radiator core. They should be just as hot. If they are not then the outer sections of you radiator core are clogged. Don't waste your time with any type cleaner buy a new stock unit if the radiator fails the 'feel test' I just described.
Forgive us all if anyone of us, (me in patricular) goes over covered territory again. This thead is longer than my memory can handle.
If it is running too lean it will run quite hot also.
Did you test the thermostat to see if it actually opens? If not pull it and dip it in boiling water MAKE sure it is in the right way also.
One other modification can make a block over heat. If the block has been bored out quite a bit you lose a lot of needed metal between the cylinder and the water jacket.
Try a lower temp thermostat (160-180) in any event.
Let's hope you can get this enigne heat problem under control!
The tstat is new. 180 was tired then put back to 195.
The block is stock. head was redone and new gasket.
Thing is not running rich or lean. Seems fine there.
This is a tricky one. If both hoses are new, water pump new, radiator is new, fan and shroud are good and correct, thermostat is good, and everything pressure checks ok, then there is only one thing possible. The head gasket could be on the wrong way blocking coolant flow. I believe you said that it heats up pretty quick, take the thermostat out and see if it still heats up quickly. This will give you max flow and should make it take fore ever to heat up. Also, when i install a new thermostat i like to drill a small hole (1/8") in the stat to help rid of air pockets. If it still heats up then there is a restriction some where. Most of my cooling problems have been either from a lack of air flow or the water pump was going south.
AS soon as the temp gauge reads in the 220 range check both upper and lower hose to see if they are equally hot. If they are not then you may have a restriction in your coolant flow. It is either a head gasket blocking a return/feed port on the head, possible but low in the list. A water pump that is not turning in the right direction or your belt is on wrong, (ditto) A bad thermostat (ditto). Air in the system is a better possibility since I believe that you said the temp spikes IIRC).
Or your block is clogged.
This assumes that all other work done is good and your fan shroud and fan are in place and in good working order. This edumacated guess is based on the fact that you have pretty much pulled, changed, checked, and rechecked most if not all of the possible items that could cause the high heat problems.
I skipped to the end, but have you checked for a clogged Heater Core? I had this same issue in a 5.0 mustang, and the blocked heater core was restricting the cooant flow enough to make a HUGE difference. Just my .02
I skipped to the end, but have you checked for a clogged Heater Core? I had this same issue in a 5.0 mustang, and the blocked heater core was restricting the cooant flow enough to make a HUGE difference. Just my .02
My 92 is a 4 cyl. That I can not get to run hot enough.When I went to parts store to get a t stat one counterman tryed to give me a wrong gasket,the other guy corrected him.The wrong gasket would have blanked off the bypass restricting the total flow to just what could go through the tstat.Perhaps I should have gone with might warm the little jewel up.Long story just to ask if you checked the gasket part #.
My 92 is a 4 cyl. That I can not get to run hot enough.When I went to parts store to get a t stat one counterman tryed to give me a wrong gasket,the other guy corrected him.The wrong gasket would have blanked off the bypass restricting the total flow to just what could go through the tstat.Perhaps I should have gone with might warm the little jewel up.Long story just to ask if you checked the gasket part #.
Just went over the issues you have with the overheating :brickwall , maybe i missed it but did you ever check the coolant sensor for putting out a correct signal? i found some specs to what the sensor should put out, this info is for a '89 2.5 TBI, but odds are 99/100 that these values apply tfor the ecu of all yj's
Coolant Sensor Test(sensor is a NTC, negative temperature coefficient, meaning when temperature rises resitance drops): Should range from 100,700 (100.7K) Ohms at –40°F to 185 Ohms at 212°F. So boil water put in the resistor and read the resistance, should be around 185Ohm.
You replaced almost everything mechanical in the coolingsystem and now it's running when driving steady at 210? mine is also at 210 but stays there when idling. I'd try running the interiorfan at hot and full speed when idling and see if this results in lower temperature readings, if it does i'd suggest you get a higher rated radiator(to dissipate more heat), install a flowcooler(for added flow when at idle and get an 17LBS rated radiator cap (quadratec all) and run 50/50 glycol/water mixture and get a 270°F boilingpoint, this suppresses gaspockets to form, never use 100% water because of this problem.
Thanx guys. I have tried it all. Even replaced the factory guage with a sunpro and it read hot. Like 250+ I shut it down before 260 so not to blow things up.
I htink the fan is wrong on the Jeep and I purchased a used one that should be in next week. Once I get that on Ill let it run and see what happens.
IM to tired to read all the answers. Do you have a remote digital temperature gun? Fluke sells them for $145 Craftsman $122. Grainger @$200. There is a lazer pointer that points at the part you want to get a temperature reading. Rather accurate I must say.It emits an electroststic emission and when it returns the led will tell you where the hot spot is. Good Luck.D
IM to tired to read all the answers. Do you have a remote digital temperature gun? Fluke sells them for $145 Craftsman $122. Grainger @$200. There is a lazer pointer that points at the part you want to get a temperature reading. Rather accurate I must say.It emits an electroststic emission and when it returns the led will tell you where the hot spot is. Good Luck.D
Well the Jeep wont start. the battery went dead. Had to get the charger out. I did get the new fan on and i am letting it run now. Not sure how this test will go as its in the 60s now and no hood. But it does seem to be moving more air.
Here is the new fan installed. This is off a 93 4.0 looks small but I think it will do the job. To bad now its cool out and in the 60s and the hood it off it but it did seem to run at 210 in the driveway. I let it run a for a while. Ill have to put the hood back on and take it for a drive to see what happens.
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