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How much effort to replace radiator?

lane hog

NAXJA Forum User
Location
Tucson, AZ
OK... it's an overheating problem, which I know I'll get abused for because there are a gazillion threads on overheating... But I'm not asking if the radiator is the problem. I'm assuming it is... !!!1

1) Bought a 2000 with the 4.0 A/T, and after driving it 20 miles from the dealer (about 25 minutes of runtime) running at 210F, I hear the "Check Gauges" chime and notice the water temp sitting at about 240F. Get parked, idle down for a few minutes, and the temp drops back to 210F. Tried to turn on the heat, but get nothing but cold air with the engine running.

2) Return it to the dealership (15 day warranty on powertrain), who replaces the water pump (presumably why the heat wasn't working...). Take it out on the interstate for a speed test, and the temps stay at about 215F including 10 minutes at 40-45, 10 minutes at 65, and 10 minutes at 50. Then I get the chime again, and the temp jumps to 240F again. Put the heat on, and about 60-90 seconds later, the temp jumps back down to 215F. Not gradual at all -- it just dropped immediately.

3) Five minutes later, still going about 45, same thing happens, turn the heat back on, and it drops back down again. Except now the "Check Engine" light is on and staying on.

After about 25 minutes of cool down, I still hear bubbling inside the top hose, and the overflow bottle is just about full. After an hour of cool-down, the overflow bottle is half full again...

Having read the other overheating threads, I know I have a lower hose without a spring, and this is happening so randomly that I haven't been able to see if it is collapsing or not (my first concern has been to get the temps down, and it has yet to do this in the driveway....). So, it has to be replaced, and I have to find a spring and an OEM thermostat. Those are quick and relatively cheap fixes compared to the water pump (which was on the dealer's dime, fortunately)...

But I'm pretty convinced that the radiator will ultimately be the culprit based on what I've read. This thing sat for several months without being run, and based on the water pump failure, I'm guessing the radiator is pretty well corroded if not partially blocked, so RadiatorBarn has the 3-tube available for $165.



Now the question....... I'm somewhat mechanically inclined, and have replaced my fair share of hoses and belts, but I've never done a radiator.

Is this a one hour project? A three hour project? Or should I just bring it to a radiator shop and let them deal with it?

Thanks in advance...
 
My friend and i replaced his radiator and took us less than an hour from start to finish. just drain it, unhook all hoses and unbolt the brackets and lift out. then put in new radiator, hook it all up and fill it up and ur ready to go. very easy replacement. dont bother with radiator shop.
 
I replaced the radiator on my 95' with a 3 core from radiator barn about a month ago. It is a relatively easy project that will take about 3 hours taking your time. When I was replacing the radiator I also changed my fan clutch (witch was oozing fluid), my thermostat, water pump, Belt, hoses and tranny cooler lines.

All you need to do is; drain the system, remove all the hoses, remove the tranny lines, remove the 2 bolts on either side attaching the black support to the front clip, then the bolts across the top of the black support. dissconnect the electric fan harness and remoce the electric fan and the fan shroud. Once you have all of that off you can pull the support off and expose the top of the radiator, condenser, and tranny cooler. Finally, you remove the bolt on either side of the condenser that holds it to the radiator. Now just pull the radiator out the top, place the brackets from the old radiator and place them on the new on then drop the new one in place. Reverse the disassembly and you're complete. Easy.

I may have skipped a step or two but that’s what I remember off the top of my head. Its not a bad job at all. I suggest replacing the fan clutch while the radiator is out. It makes it very easy and it’s a part that can cause a cooling problem as well.
 
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A little trick that has saved me a lot of aggravation, is to cut a piece of cardboard to cover the inside of the radiator, affixing it with duct tape. Depends on how much disassembly you want to do. If you leave the fan on and the shroud hanging on the fan, chances are you are gonna flatten some of your radiator fins or worse.
I actually found the hardest part was getting the condenser mounting bracket screws loose (they were frozen/rusted), so I could spin them out of the way.
I greased all the fasteners, the first time I pulled my radiator out, I can do it in half an hour now. I use a battery powered XXXX (with a socket and/or torx bit) for most of it.
 
Radiator is easy to replace.....

RadiatorBarn.com. Get the 3 core heavy duty rad.

But if it's a 2000 with the 0331 head........................

Have the dealership check for a cracked head.

Replace the thermostat while your at it.

Don't worry about the lower hose. The new construction of hoses doesn't need a spring.
 
I would say your best bet, and cheapest, is to put in a new thermostat. You can also get a good radiator flush kit that will be cheaper and will possibly solve the problem for $20 rather then $165 for a new radiator. Your problems are sounding like a stuck thermostat to me. just my $.02
 
I had a similar problem on my 89 cherokee. I replaced the water pump, thermostat, and water bottle. Still over heating. I then figured it had to be a blockage somewhere. So I removed all of the lines and flushed them clean. Hooked everything back up. Still over heating. I thought about it for a while and remembered that the only thing I didn't backflush was the heater core. I removed the lines hooked my water hose up to it and it took a couple of seconds for the the water to build pressure, but in an explosion a big wad of mud looking shit and rust came out of the other side. Hooked everying back up, refill the system, and voila, never overheats and the Heat is hotter than it has ever been.
 
Thanks for all the replies.

Checked inside the oil fill cap, and there's no evidence of white stuff, so I'm guessing it is not the block although I'll try and get a compression check just in case.

I'll be changing out the t-stat and flushing over the weekend, but this is the high desert -- 100F is the norm during July and August, and the stock radiator isn't designed for that. If nothing else, the radiator may bring me some added peace of mind and help avoid a cracked block down the line.
 
Update... Replaced the t-stat today with an OEM replacement Mopar. Burped it, drove about 20 minutes and the damn thing overheated again....

So.... it's not the t-stat. It's not the water pump, and there was no evidence of oil inside the top of the head, nor was there any evidence of coolant being burned in the exhaust pipe or underneath the oil fill cap.

There was a lot of calcium buildup inside the thermostat housing and also on the inside of the water pump they replaced. I'm really not looking forward to what may be in the radiator itself, so.... tonight I may just pull the upper and lower hoses off, and let it soak in a couple gallons of straight vinegar overnight before flushing it tomorrow.

If that doesn't do the trick, I've got a 2000 XJ with Skyjackers, a great body, and only 78.9K miles on in available for trade... ;)
 
I replaced the rad in my old 87 twice (never replace with a used rad)
and the first time i didnt have the right torx bit.

Long story short you can blow apart the whole front end with nothin but vicegrips:gee:
 
do your flush an see if that helps, keep track of time when it heats up..If you got the rad real clean then it will take longer to heat up on test drive, if it does take longer then it is time to buy a new rad
 
lane hog said:
After about 25 minutes of cool down, I still hear bubbling inside the top hose, and the overflow bottle is just about full. After an hour of cool-down, the overflow bottle is half full again...

You can hear it boiling and you're pushing a whole bunch into the overflow bottle? I'm thinking it might be as simple as a bad radiator cap.

At the stock 16-psi pressure using 50/50 antifreeze boiling should be 260*F. I'd go buy a new 16-psi cap (not 13-psi like autozone tells you) and try that first. You should replace that when you do a new radiator anyway.
 
I would have suggested checking the Aux fan to make sure it's running, but the report indicates the heating is coming and going suddenly tells me there is something else funky going on. I suspect a radiator would not do that, nor a bad fan as those generally take a while to cool after the engine overheats.

I had a 2.8L do that sort of thing. The temp gage would fly off the scale, then come back down to normal temp, then later down the road whould shoot off the scale again. I replaced the T-Stat and a whole pile of stuff. Even took the t-stat in the house and boiled it on the stove with a thermometer, worked fine.
Nearest I could figure out was that the head gasket was bad and it would occasionally pressurize the water passages, then seal itself and the water would rush back in, turn to steam and send the sender through the roof. I had another motor around and swapped it, but never got around to pulling the heads to verify the problem.

Oh, on the radiator R&R: The lower tranny connection on the radiator takes a special tool, but you can replace that piece of line with a piece of regular fuel line with no ill affects.
Took me about an hour to remove, repair and reinstall my last radiator (trail incident) on my 98' 4.0L AT.
 
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The flush didn't do the trick, so I brought it back yesterday. Got a call this morning, and the mechanic who looked at it decided the radiator was probably plugged. They're replacing with a three-core (my request, I'll pay the extra $30 for peace of mind).

I also asked for them to do a compression test so that it isn't going back a fifth time. No word yet on the results, but I can only assume that no news means that they didn't like the results...
 
Passed the compression test OK, so it isn't the head. Yet. ;)

Got it back today, and it ran fine. Even got to go wheeling a bit down in one of the washes today, and it didn't budge from 210F....

The dealer wound up doing the radiator swap-out, so I missed out on the fun, but I'm sure that there will be plenty of other chances to fix stuff on the XJ...
 
Looks like I will be joining the party

Well shizit! Today when poking around under the hood I found tell tale signs of a little coolant splashing around under the hood and it appears to be coming from the upper radiator hose nipple where it attaches to the radiator. My radiator is all brass/metal so there must be a crack/corroded spot there. Other than this slow leak my temp stays fine and all else works great.

Should I try to partial drain and pull upper hose, smear JB weld around the return nipple and then then see if it seals?

Or just concede loss and buy a rad? Hate tossing one that cools just fine.

Is everyone still all about the CSF 3 row? Any other good contenders?

Thanks.
 
Re: Looks like I will be joining the party

find a radiator repair place, have them braze the nipple back to the tank. You could probably do it yourself if you cleaned it up real well and used a torch and some rod.
 
i just had the same issues, replaced evertyhing but the rad. finally broke down and did it. Just got an advance auto parts special for like 89 dollars. Cant beat that and its got a lifetime warrantee Make sure you have disconnect tools for the tranny cooler, that one caught me offguard.
 
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