My 96 Cherokee Still overheating after much money put into it
Ok, so I bought this 96 Jeep Cherokee. I noticed it would overheat after extended driving (at the tail end of the drive, and when pulling into the driveway). When I come to my final stop and idle for more than a minute the temp goes up and it will edge slowly towards the red if I don't turn the heater on full blast.
So far I have put in a brand new 195 Stant Thermostat. A brand new radiator. I bought a new radiator cap, and found out yesterday it wasn't holding 16psi like it was supposed to. I bought a new rad cap, and thought I fixed my problem. Well turns out I didn't. I also burped the system very well.
So then I replaced that catalytic converter because it was rattling.
Oh and there's fresh coolant 50/50 with distilled water.
The water pump looks brand new.
I also replaced the fan clutch, and the fan shroud.
I had a mechanic do a pressure test on my cooling system, no leaks, and he said it didn't show any signs of cracked head, leaky head gasket, or warped head.
Also bought a combustion leak tester and did it 3 times, following directions to the tee. It didn't show any signs of combustion gasses in the coolant.
Is there anyone in Colorado Springs that would be willing to help me get this figured out, I would compensate..
otherwise please post any advice you might have.. Thanks.
I always drive to the store (about 5 miles away). The trip there is fine always stays at about 200. After coming back to the car after 30 mins of shopping, the drive home is where I run into trouble. This is consistent, happens every time.
Check the OVERFLOW TANK HOSE. I had a vehicle that would act like this, turned out the thing would spit hot coolant into the overflow fine but wouldn't suck back in due to a TINY crack in the hose to the overflow tank.
if I hit it... you owe me a picture of the first trail you run without overheating .
97 TJ Sport - 4.0/HP D30 w ARB/8.8 w LS/4.88s; 35s and flat fenders on 2.5 lift
84 CJ7; frame off restoration in progress.
The technical advice you get from me here is worth exactly what you paid me for it. Warranty issues will be reimbursed at double what you paid me for the advice.
Jeep has a water pump that will bolt on another model with the same block. It's made to turn a different direction. Check your pump to make sure yours is correct. They are cheap and easy to install. I'd put on a known good one. Check your lower hose for collapsing and restricting flow. It should have a spring inside it to keep it open. Remove hoses and flush the heater core if you haven't already.
try taking the thermostat out for a bit. With a problem like yours, it helps to troubleshoot one piece at a time. I have even heard that some guys get better cooling by adding a restrictor in the hose to increase dwell time in the radiator. Check the water pump -- If it is reverse rotation (the pulley runs on the smooth side of the belt, not ribbed) then the pully should be smooth.
Does it overheat at sustained speeds above ~45? if so, the coolant is not moving properly through the system.
Clogged heater core. Maybe try bypassing the heater by looping the input/output hose. Make sure you have reverse rotation water pump, as mentioned above, although I would think this would cause immediate overheating. Make sure your new fan clutch is not faulty. Is it hard to turn the fan with your hands when the engine is hot? If not, it's not engagine properly. Did the Stant thermostat have the little bleed hole in it like the OE one? Sometimes that makes a difference. And lastly, you could still have an air bubble that you didn't get, although sounds like you were on top of this. That's all I have.
clogged heater cores have been mentioned on many threads here but will NOT cause a overheat issue.Many people install a valve just to keep heat from being able to enter the passenger compartment which would in effect be the same as a clogged HC.If you think you do have a clogged HC you can reverse flush it using a 5/8 barbed hose fitting to clean the HC but it will not fix your problem,and you do mention that you can control the overheat by turning your heat to high and cool it down some. check to make sure you have the wire inside the bottom rad hose and it is not collapsing,after that I would find out if you have a reverse rotation WP.Again a clogged H core will not overheat you it will simply bypass the HC.
Ya this has nothing to do with the heater core. My heat blows hot.. and its about the only thing that will bring my overheating to an end..
Update: Drove it for 20 minutes in town, stop and go, no problems, thermostat opening was visible on the gauge, 10 more minutes and it steadies out at 210, then i get on a road that's 55mph and it starts to get around 212, then theres some more traffic lights and it acts like it wants to heat up. I finally pull in my driveway and its heading towards the red. The electric fan comes on and i blast the heat and i get it back down to 210, and shut it off. Opened the hood and ITS HOT, both RAD HOSES ARE HOT (probably pretty close to the same temperature) and VERY PRESSURIZED
If you figure it out, please post. I have a 1998 with what seems to be the same problem. New Hesco water pump, new radiator, new hoses, new fan clutch, new thermostat and Hesco housing, new radiator cap, system holds pressure based on tester, and does not seem to be building pressure from combustion into the coolant system. I back flushed the heater for the hell of it, but I didn't think that would help. I'm stumped.
You guys burp the system? Grab the top hose, squeeze it. If you hear shloshing.. there is air in there. And what temp is "overheating"? Have you measured it with anything else to rule out your sensor just being bad?
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Do you have any unexplained coolant loss at all? You might want to do a compression test just to be positive about head and gasket even though you have tested for exhaust gasses in the coolant and if you do a comp test look at all of your plugs and notice if any are a lot cleaner than others.
One other thing that I just noticed is that you say the WP looks new but you yourself are not certain of the condition of it or when the PO replaced it and what with?? Why not replace it and make sure,I've seen several posts here where the impeller was eaten up and one that was gone all together.From what I recall it sounds like the only part of the cooling system you have not replaced.When you started replacing everything was that for the over heat issue you have now or was it just you wanted to get your cooling system up to new condition? When you started replacing everything was the coolant really rusty or muddy and did you do a complete system flush? Sorry for all the questions,just trying to help.
Last edited by buildin1XJ; 08-29-2012 at 09:23 AM..
Reason: wanted to ad to my post
Besides checking the impellers conditions, I would remove the thermostat, flush the cooling system with clean water and then use a HD chemical flush, the type you add and then drive for a few hours, not the quickie flushes.
If the coolant comes out dirty and black, do it again to remove any buildup in the block. Use distilled water when replacing the 50/50 mix.
Assuming you have A/C, the area between the condenser and radiator can fill with all sorts of small debris. You cannot see this area without removing the bracket that holds the top pf the radiator in place. Remove the bracket and pull the radiator rearward, to see behind it. I have found all sorts of fluff between mine, mostly from floating seeds packets.
If the condenser's fins are bent, they too will restrict air flow. They can be straightened with a fin comb, available online or at a A/C supply shop. http://www.amazon.com/Mountain-8300-.../dp/B000JFL8HK
2001 Sport, 4" lift, 33 X 10.50 KOs, R.E. DB, R.E.-UCA, JKS-LCA, ACOS, 8.25-4.56-TruTrac, SYE, D-30 E-locker w/alloy shafts, Hidden M8000 winch, Vanco front and ZJ rear disc brakes, Lots of armor, Towing baseplate. http://www.flickr.com/photos/lwade/c...7603770130683/