Ok, I have a '98 4.0 and I have a strange cooling system issue... I think I know what it is but I want to see what you guys think! Here it goes;

Had a radiator leak, and had a slightly dirty cooling system so I had it flushed by a radiator shop, cleaned all the gunk out perfectly, then I went home and cleaned out the overflow resi, and prepared to install my new 'silla' radiator.

Said silla radiator looked like a true made in china POS! The thing was not straight square or anything of that nature, fit terrible. The bottom of it had an arc that was ~1/2" in the center (horizontally) if that makes any sense. Also the filler neck hit the air box and also didn't seem to be perfectly round or true/flat where the cap screws in!! However, as usual I was in a time crunch and needed to get it in and back together to get to work. Went ahead and reluctantly installed it. All seemed fine....

Now whenever I get the jeep up to temp for an extended period of time (and temps seem to be good according to temp gauge) and then shut the jeep off, about 1-2 min after shutting it off antifreeze begins to dribble out of the filler neck/from under the secured radiator cap.... (Approx. 1 cup maybe)

What would cause this? Any ideas??

 

My thinking is its either the radiator cap isn't really sealing properly, however it only leaks after turned off OR maybe the overflow tube got gunked up and isn't letting fluid through???

My nephew's for ranger had a slow leak and he put some kind of stop leak garbage in his cooling system which filled his overflow bottle with a clay like gunk, and for some strange reason when I cleaned it out for him I took the blower nozzle from my air compressor and blew into the line and gunk shot all over (line was actually clogged) which is making me think maybe I have the same issue and after its turned off it can't release pressure?

I just don't know enough about cooling systems to know if that theory makes any sense or not, and like I said I'd like to see if someone with some cooling system knowledge can confirm or give me any advice...

 

sounds like the radiator cap isn't secured.. it should flow into the overflow bottle..

what it really sounds like is you got a POS radiator.. and need to get your money back and a new one shipped!

Hell I ordered the rock auto special.. they wont even guarantee what brand you get, and it fits and functions perfect.

 

It also sounds as if you might need to bleed the system a little better...

 

Thanks, and that's kinda what I'm thinking, I'm just so very disappointed with this radiator I hope they will give me my money back or at least store credit! I will not take another one of these, I'll go back to a csf or whatever napa has...

I have to replace the alternator anyway, so I think I'll get a new radiator, alternator, belt and maybe tensioner and just do it all at once. Water pump and thermostat are new. That way I can kinda make things easier on myself, and I can bleed it/burp it more. I really really didn't want to install the crooked piece of junk, it looked like a blind one armed monkey that was high on meth built the dang thing but I didn't have another day to waste changing it out again....

 

LOL you can remove the coolant temperature sensor on the rear of the head... it helps to purge air out while your filling.. its just a huge royal pain in the *** to get to.. its nestled right next to the valve cover.. you will see... a crows foot would make it easier.. i just didn't have any special tools when I replaced mine

But the easiest way that I do it with almost every vehicle I work on... is massage (squeeze) the radiator hoses while I'm filling, helps to work the coolant in and the air out...then crank, drive, park, fill. Let the thermostat open up.. check it for a few days with a bottle handy..

 

Cool! Thank you for the advice!!
I really appreciate it!!

 

anytime!

 

Guys, he doesn't have a gauge/idiot light sender at the rear of his head. If the 96 does, that is absolutely the last...I'd thought that moved to the T-stat housing sooner. Pulling that on a stubborn closed system Renix, (87-90), isn't really necessary, the later should burp OK in any case.

JB, you might just try another cap...... It has two seals. One holds pressure with a spring, the other sends what gets past the spring to the recovery bottle. Then when the system cools it sucks that back in through a check-valve in the cap.

 

Sorry bud, I thought for some reason I read you had a 96 which DOES have the sensor at the rear of the head.. but I believe it IS the last year with that...

You absolutely do not need to remove that... It just sometimes makes it easier to burp stubborn cooling system when you have somewhere for the air to go.. regardless.. it was just a suggestion if you were having a hard time purging air..

squeezing the hoses DOES help to quicken the "burping" process... not just on cherokee's, but many different models, is it necessary for the 4.0? I don't really know, I just ALWAYS do that.. one of those.. watching dad things growing up

Anyways.. these were just suggestions that have helped me in the past...

I didnt think his original cap seals were bad.. since he described the coolant inlet for the cap somewhat egg shaped..

 

I did miss that! Maybe Ebay has egg shaped caps!

 

I would hate to see that Chinese Quality Assurance inspector...

"meh... it rokay! lika circle"

 

Thanks for the replies! I'm pretty sure its burped good, I did try another cap but it was an extra I had from another cherokee and same thing. I have not however tried a brand new cap, and I'm sure regardless a new cap would be money well spent so I'll get a new one and check it out.

Like I said the quality control at silla is obviously non existent. I have replaced A LOT of radiators over the years, probably 20+, some of the 'el cheapo's' and I've never seen anything like this one. I'll be having a chat with O'riley's on that.... And I'll without a doubt be taking a much more thorough look at any radiator I buy from a parts store from here on out! I should have never put it in... But late sunday night with work on Monday and at the time only having one vehicle left me little choice.

 

Removing the temp sending unit at the rear of the head on '96 down XJs and/or jacking the front end up r both myths perpetuated in forums and on the Net. The front of the motor is higher than the rear, presuming the vehicle is on reasonably level ground. Air naturally migrates to the highest point it can move to in a liquid. If the cooling system is filled slowly, stopping occasionally to allow air to migrate up, "burping" the cooling system is a non-issue. The "open system" rad cap is critical to coolant recovery system functioning properly. If the rad cap is leaking coolant "out" when hot, u can bet the cap is leaking air "in" when the motor cools......not good.

 

Sounds like a bad cap to me. Mine did the same thing a couple months back and a new cap solved my problem. Then two weeks ago my radiator split on the seem so I installed a new one from Advance Auto Parts. The radiator was $73 plus tax due to the online coupon code. I picked it up in my local store the same day and it fit perfect.