Jeep Wrangler TJ Cooling System Overhaul FAQ

[Bowhunter]

Hey All,

Just picked up a clean 03’ Rubicon automatic which I believe has the 42RLE. Coolant has a brown tint to it so it’s likely time to replace the cooling system (want to make sure I don’t overheat this rubicon because it’s the cleanest TJ I’ve seen in years)

On the first page it lists 2000-2004 with the auto as one part number but 05-06 (with the 42RLE) is a different radiator.

Do I go by the year of 03 to be in the AB radiator or go off the transmission and go with the AC radiator for the 05-06 jeeps?

 

[Link]

Food for thought…..

If you have an older radiator there is a good chance your radiator cap isn’t holding pressure. Unless you are driving in a hot area, your Jeep really doesn’t need the cooling system to be pressurized in order to still work. But, when you replace the radiator cap with one that works (holds pressure) there is a good chance the old radiator will fail shortly after. The new radiator cap doesn’t cause the failure….the old radiator was on its way out but with no pressure in it, it doesn’t fail. Once pressurized it may fail soon after.

I have seen this phenomenon with several vehicles in my lifetime.

 

[Link]

My factory Mopar radiator in my 2005 failed. Think it’s probably the original but don’t know. Going to replace it with a Denso tomorrow. Here’s a few pics of where it failed. I may do some destructive analysis tomorrow and disassemble the old radiator. The top tank split lengthways in a couple places.

 

[MountaineerTom]

My factory Mopar radiator in my 2005 failed. Think it’s probably the original but don’t know. Going to replace it with a Denso tomorrow. Here’s a few pics of where it failed. I may do some destructive analysis tomorrow and disassemble the old radiator. The top tank split lengthways in a couple places.

View attachment 421040

View attachment 421041

View attachment 421042

My ‘06’s split in about the same place in 2017. I’m pretty sure it was the original too.

 

[Link]

Here is the factory Mopar vs Denso pics. The Denso was purchased from Rock Auto. About $170 with tax and shipping at the time of this post (2023). Sticker on it says “Made in Indonesia”. It should be obvious which is the old radiator and which is the new one. The Denso bolted in with no modification. The tubes inside the Denso appear to be a little wider than the Mopar but not enough to make any difference I don’t think.

Weight wise they were very close. I don’t have a scale to weigh the two radiators but the weight is very similar. I think the Mopar MIGHT be a fraction heavier but that’s pretty subjective. So, weight is nearly the same.

 

[Link]

Here is the destructive disassembly of the Mopar radiator. I noticed something interesting about part numbers inside the lower tank. The upper tank felt softer than the lower tank so my suspicion is the higher heat in the upper radiator is harder on the plastic than the lower so the constant heat and cool cycles weaken the plastic on top first. The crack near the fill cap doesn’t appear to be all the way through but the one at the input hose IS all the way through….and is the source of my leak. It’s also interesting it’s near the hottest part of the radiator which also appears to suggest that heat is what does in the plastic tanks. The radiator tubes appear to still be in good shape. If you have a question about something you would like to see close pics of or more info, please ask soon because I’ll be tossing this old radiator in a few days.

 

[Link]

For what it’s worth….I just got back from a 2700 ish mile trip out west. Wide range of temps from cold enough to need a little heat to hot enough to run the AC full blast. Ran the AC a good portion of the trip. The Denso radiator kept it at the right temp the whole trip. No issues at all.

 

[JasterMereel42]

I need to replace the water pump in my 2000 4.0 engine. I see that the Mopar water pump is running about $180-200. I'm also finding a water pump from Gates for $40 and it is rated 4.7 on Amazon. I understand that the water pump is critical to the entire engine cooling system. Is this a component that is in the "only replace with OEM parts" category or is this in the "a quality but cheaper non-OEM part is fine" category? If a non-OEM part is fine, which brands do you recommend?

 

[Bowhunter]

I need to replace the water pump in my 2000 4.0 engine. I see that the Mopar water pump is running about $180-200. I'm also finding a water pump from Gates for $40 and it is rated 4.7 on Amazon. I understand that the water pump is critical to the entire engine cooling system. Is this a component that is in the "only replace with OEM parts" category or is this in the "a quality but cheaper non-OEM part is fine" category? If a non-OEM part is fine, which brands do you recommend?

To be honest with you, I can’t give you actual experience because I still have my factory pump (my warming up issue was the radiator).

From my research you will find people on both sides of the fence. OE mopar has a pretty strong following (including me on the radiator) but others will say the higher end store brands will work (like Napa). Kind of your mileage will vary thing

While it’s not a hard job, it would suck to have to do it again if a cheap pumped failed quickly. If/when I have to, I’ll probably go mopar

Here’s a good write up by Chris with part numbers

https://wranglertjforum.com/threads/jeep-wrangler-tj-cooling-system-overhaul-faq.3397/


https://www.amazon.com/dp/B00FZP1LT4/?tag=wranglerorg-20

 

[Link]

I need to replace the water pump in my 2000 4.0 engine. I see that the Mopar water pump is running about $180-200. I'm also finding a water pump from Gates for $40 and it is rated 4.7 on Amazon. I understand that the water pump is critical to the entire engine cooling system. Is this a component that is in the "only replace with OEM parts" category or is this in the "a quality but cheaper non-OEM part is fine" category? If a non-OEM part is fine, which brands do you recommend?

I have used Gates water pumps in many different applications all with excellent results. I have a Gates in my TJ now (2005) and it's been fine as well. I would be hesitant to buy any parts from Amazon though. Amazon is notorious for selling counterfeit parts. I got mine through Rock Auto. The Amazon one might be genuine....but it may also be counterfeit.

 

[MikeE024]

I have used Gates water pumps in many different applications all with excellent results. I have a Gates in my TJ now (2005) and it's been fine as well. I would be hesitant to buy any parts from Amazon though. Amazon is notorious for selling counterfeit parts. I got mine through Rock Auto. The Amazon one might be genuine....but it may also be counterfeit.

If it were me, I’d go Mopar if I had the money or I’d get one from Napa. That’s just my gut instinct talking.

I don’t trust Gates water pumps as much as I used to after one leaked on me right away.

 

[Tob]

I bought one listed as mopar, it showed up looking cheap and different from the original. I bought another "mopar" from somewhere else and got the same thing. You probably can't get mopar unless it's NOS. All the parts manufacturing is probably just the same old Chinese stuff with the mopar name slapped on. It sucks but it is what it is.

 

[G Crawford]

New Jeep driver here. I bought a 2005 LJ a few months back with 130,000 miles on it. No current issues with the cooling system but with the miles the Jeep has I have decided to replace my cooling system and timing chain. This Forum has provided me a wealth of information on this little task. However, I have ran into several issues in just obtaining the correct parts need for the cooling system. I ordered a MOPAR radiator and it just didn't look the same as the stock radiator, so I sent it back. Now I'm waiting for Amazon to deliver a MOPAR radiator. I was able to purchase an water pump from the Jeep dealer.

One issues I'm having is locating new spring clamps for the radiator hoses. I've looked at the Jeep factory parts IPB and when I went to the dealer and provided the counter guy the part numbers
IPB: 7, 2ea 5200 5580
IPB: 25, 6502 089
IPB: 26, 3200 2366

He stated that the number were old part numbers and the I needed to provide the updated part numbers. This is what I have came up with.

IPB: 7, 55037990AA
IPB: 25, 06502089
IPB: 26, 55037660AA

What is everyone else using for spring hose clamps?

 

[MountaineerTom]

New Jeep driver here. I bought a 2005 LJ a few months back with 130,000 miles on it. No current issues with the cooling system but with the miles the Jeep has I have decided to replace my cooling system and timing chain. This Forum has provided me a wealth of information on this little task. However, I have ran into several issues in just obtaining the correct parts need for the cooling system. I ordered a MOPAR radiator and it just didn't look the same as the stock radiator, so I sent it back. Now I'm waiting for Amazon to deliver a MOPAR radiator. I was able to purchase an water pump from the Jeep dealer.

One issues I'm having is locating new spring clamps for the radiator hoses. I've looked at the Jeep factory parts IPB and when I went to the dealer and provided the counter guy the part numbers
IPB: 7, 2ea 5200 5580
IPB: 25, 6502 089
IPB: 26, 3200 2366

He stated that the number were old part numbers and the I needed to provide the updated part numbers. This is what I have came up with.

IPB: 7, 55037990AA
IPB: 25, 06502089
IPB: 26, 55037660AA

What is everyone else using for spring hose clamps?

View attachment 439870

I compiled some info on constant tension hose clamps a few years back. Some p/n's are the same as what you listed, so that part may not help. The link for Clips and Fastener's website may have some equivalent clamps. Hopefully this will help you some.

https://wranglertjforum.com/threads...urces-for-constant-tension-hose-clamps.28271/


The SAC patch has always been my favorite USAF patch. I tried to get stationed at B-52 bases many years ago because of it, but never got one.

 

[NashvilleTJ]

New Jeep driver here. I bought a 2005 LJ a few months back with 130,000 miles on it. No current issues with the cooling system but with the miles the Jeep has I have decided to replace my cooling system and timing chain. This Forum has provided me a wealth of information on this little task. However, I have ran into several issues in just obtaining the correct parts need for the cooling system. I ordered a MOPAR radiator and it just didn't look the same as the stock radiator, so I sent it back. Now I'm waiting for Amazon to deliver a MOPAR radiator. I was able to purchase an water pump from the Jeep dealer.

One issues I'm having is locating new spring clamps for the radiator hoses. I've looked at the Jeep factory parts IPB and when I went to the dealer and provided the counter guy the part numbers
IPB: 7, 2ea 5200 5580
IPB: 25, 6502 089
IPB: 26, 3200 2366

He stated that the number were old part numbers and the I needed to provide the updated part numbers. This is what I have came up with.

IPB: 7, 55037990AA
IPB: 25, 06502089
IPB: 26, 55037660AA

What is everyone else using for spring hose clamps?

View attachment 439870

Sweet shop - and I love Benny Hill as well!

 

[TJ Jim]

Benny for the win

 

[G Crawford]

Tom, thanks for the the information and link. I knew a weapons loader named Tom from Kansas way back in the day. Great guy, as you probably are too. Congratulations guys on being selected as Ride of The Month Winners. It's an accolade to wear proudly.

Spending years in England will turn anyone into a Benny fan.

People on this Forum are the best.

 

[James9100]

What’s the recommended brand (besides Mopar) for a thermostat housing?
My parts place has Dorman and I think Four Seasons in stock, Gates I’d have to order in.
All about the same or is one higher quality?

 

[macleanflood]

What’s the recommended brand (besides Mopar) for a thermostat housing?
My parts place has Dorman and I think Four Seasons in stock, Gates I’d have to order in.
All about the same or is one higher quality?

We've had to sand all of them flat. I don't think it matters much. I bought one at O'Reilly's and it took four attempts to seal it up...last attempt required sanding the new housing and block. I like Gates as a brand, and Dorman and my Four Seasons heater core doesn't suck. Probably all cast by the same group of 4 year olds in China anyways.

-Mac

 

[CoolhandLW]

Awesome thread! My radiator blew yesterday on my 06 LJ daily driver. I'm doing a full swap as suggested. All parts are ordered and arriving this weekend except the thermostat gasket which cant get here until Tuesday. Is there a similar one i could use that will be good enough or do i order the Standt 25160 and wait until it arrives on the 17th to get started?