I had overheating issues before and after replacing the cooling system.
It turned out to be a leaking head gasket.
Jeep Wrangler TJ Cooling System Overhaul FAQ
- Thread starter Chris
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I had overheating issues before and after replacing the cooling system.
It turned out to be a leaking head gasket.
MCHeiner90
New Member
I have been chasing down cooling issues for a while now. On my last outing my jeep overheated on an uphill and spewed coolant in the engine bay. I haven’t determined where it came from, but have not had that problem since, though it struggled with overheating the rest of the day and I haven’t pushed it too hard since. After reading this thread I decided a cooling system overhaul was in order. The fan clutch seems to not be working properly, so I definitely need to replace at least a few components. My biggest question is the radiator. It looks fine, though I’m not sure what a bad radiator would look like apart from having a leak. There is a lot of push on this thread to use only Mopar parts, but I have looked far and wide and have been unable to find a Mopar radiator to replace the original. It is a 98 4.0 manual transmission. So, if I am unable to really determine the health of my radiator, would it be best to press forward with the complete overhaul, using an aftermarket radiator, or to keep the old Mopar radiator and replace everything else. I have been able to find a Mopar replacement for everything else. As I am not the original or even the second owner, I am assuming that it is a 26-year-old radiator.
@MCHeiner90 OEM radiators can still be found, but they are pretty rare. I think Denso radiators have a pretty good track record for aftermarket radiators.
As for a bad radiator, there could be a lot of small debris clogging up the inside of it which prevents it from cooling properly. You can open up the radiator cap at the top and look inside and see if the fluid looks clear, if there are bits of stuff floating around, or if it is completely clogged up. This is what my radiator looked like when I first got it. Needless to say, it got replaced. Replacement on the radiators is pretty easy. I think it is 4 screws for the fan shroud, I think 6 screws for the radiator itself, disconnect the hoses, and it is out.
As for a bad radiator, there could be a lot of small debris clogging up the inside of it which prevents it from cooling properly. You can open up the radiator cap at the top and look inside and see if the fluid looks clear, if there are bits of stuff floating around, or if it is completely clogged up. This is what my radiator looked like when I first got it. Needless to say, it got replaced. Replacement on the radiators is pretty easy. I think it is 4 screws for the fan shroud, I think 6 screws for the radiator itself, disconnect the hoses, and it is out.
MCHeiner90
New Member
Thank you! It looks like the Denso radiator is in stock on RockAuto. Looking in my radiator it seems pretty clean. I really don't see any corrosion and the fluid looks clean.
Have you looked to see if there is a radiator shop in your area? If there is they can overhaul it for you.
If it looks fine in there, then try the fan clutch first and see if that does it. Also, it doesn't hurt to proactively replace the thermostat. That's a $25 part and about 30 minutes of work.
MountaineerTom
LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
The original radiator in my ‘06 TJ and my ‘99 Silverado both cracked one of the plastic tanks within the last handful of years. Other than being dusty/dirty, neither had any visible signs of being bad or leaking until they cracked. I put a MOPAR back in the Jeep, but I put a Denso in my truck about a year ago. The quality seemed good to me and it has being working as it should.
I was curious what the inside of the tank looked like when they crack, so I cut the end of the tank off of the one that came off my truck. I think I was expecting to see some erosion or degradation of the plastic but it looked no different than the outside of the tank.
Yeah I said that and two thermostats later that opened at 165 when they were supposed to be 195s and I bought a Robert Shaw sourced from Flowkooler and then everything works.
-Mac
MCHeiner90
New Member
Thank you everyone. It's looking like the radiator is not that difficult to replace even if done as a standalone project. Based on the feedback here, I think I'm going to leave the radiator alone while I replace the water pump and fan clutch (and thermostat). If I keep having problems I'll look into the radiator. I do have a radiator service shop in town that could probably service it. Otherwise I'll look into getting the Denso.
Don't try to have a radiator shop repair it. Just replace it. Denso will be fine.
I followed the link for the thermostat, and I received the motorad version of the Stant that's made in israel. Is this still the best thermostat to use? For reference I drive an 04 sport and everything else is bone stock
Is it worth it with an OEM water pump, or is it a waste not to pair it with a flowkooler water pump?
I’m currently running cooler than most now…with a Gates that has an unpolished cast impeller.
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One more addition to my cooling issue that is now solved.
Two faulty coolant caps.
They both would let coolant into the overflow tank before an overheat condition existed.
Now I run a MOPAR radiator cap and the coolant temp is much lower, and no spikes due pressure lost through the cap.
Two faulty coolant caps.
They both would let coolant into the overflow tank before an overheat condition existed.
Now I run a MOPAR radiator cap and the coolant temp is much lower, and no spikes due pressure lost through the cap.
I also ordered the DENSO radiator 2219234 from RockAuto which should arrive next week. My OEM radiator seems to have finally gone bad, slight leak around the seams near the cap. I bought the Jeep new in 1998 from the dealer and have 247K miles on it, the radiator is original. I also have the original hoses and water pump which are still solid, but am replacing all since it seems like a good idea.
I hope the issue with faulty caps posted above is not a thing, at least not with the Stant cap as that is what I ordered. I can still cancel and order a Mopar. Don't think I will though unless the chorus kicks in otherwise.
I hope the issue with faulty caps posted above is not a thing, at least not with the Stant cap as that is what I ordered. I can still cancel and order a Mopar. Don't think I will though unless the chorus kicks in otherwise.
Holy Smokes on the shipping!! That shipping is from the link listed in the original post. I found the same part on several Mopar sites for around $250-260 with about $10-$15 for shipping. I ultimately bought from RockAuto for $253.94 all in.
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