DUBarado

Ok, so I've been doing a lot of research but I have a question or 2 that I cannot find answers to, so I figured I'd tack another Renix cooling thread onto the forum. I don't want to convert to an open system, but I believe I do have some air in the hoses...

As i was running it the other day in these heat waves, when if traffic the temp gauge just slowly increases from 190 to upwards of 240, and yes the electric fan is turning on.... when i'm driving it goes down to 170ish. As I got it home I noticed the big hose from the rad to the thermo was ballooned at the thermo housing, not good... I squeezed it and it was firm... I also noticed the over flow bottle was filled up to the max... I let it cool down, released the pressure and the fluid never drained back into the motor...

I disconnected the big hose from the thermo housing and blew into it (so the air traveled through the radiator, into the water pump) , thus forcing coolant out of the housing up top... but after that both the top and bottom radiator hoes remained empty.

Could this be a thermo issue? A radiator issue? I replaced the thermostat and water pump about 4-5k miles ago, last summer... I am currently at 173k and I know it's about time to replace the radiator soon.

I am going to try tapping 2 holes in the thermo tonight, if i can get the bolts loose on the housing! PB blaster is currently working it's way in.

Elexwiz

Any "ballooning" would mean a weak hose. How big was the "balloon"? How old are your hoses? If they're that weak you should replace them.

It's not supposed to be that full. I would say that you have air in there. You need to burp the system. Take the cap off the bottle and let it get to operating temp and just let it run. You can squeeze the hoses to try to force the air out. Don't forget to turn the heat on (but not the blower). Once the tstat opens you may see your fluid level rise and fall in the bottle. This is good. The air is being released.

DUBarado

Yea the hoses look old to me, like the originals lol. I will replace them. As for burping I tried and no luck. I removed the thermostat today and drove it and the temp still went up really high. I parked it on a slight decline (nose lower than the rear) and will check it tomorrow to see if it burped itself. When I run it with the cap off it starts to fill and heat up. But I will give it another shot tomorrow. I just don't want to dump antifreeze in the parking lot!

DUBarado

Well its been sitting for a week, just been really busy. Looked at it and it still hasn't burped. The only thing I can think is the radiator is clogged? Even though I blew on the upper hose into the radiator and shot coolant out the thermo housing, I think its the last resort. I did overheat it 4k miles ago, but there is no water in the oil and it was running fine until recently. Any other ideas then the radiator? And how hard will the swap be on it?

DUBarado

Anybody??? I may have to do the swap myself since I can drive it to a shop with risk of it overheating. I assume ill need a few hours, some torx, and some beer. Anyone have a write up on it?

BigBear

My 89' jeep had the open system swapped in when i bought it. It overheated and I swapped back to a closed system. Look for a 3 row all aluminum sealed Champion radiator. My temps are stable now at 210 on a 108F day. I do however have a hesco water pump and 180 thermostat.

DUBarado

How much do those radiators run about? I currently have a 180 thermo in there as well... before this issue it'd be around 160-170 driving in cooler weather, but in the warmer weather it was around 210.

DUBarado

I let it sit w/o the overflow cap and it looks like the level went down, but when i run it, it still fills up then begins to over heat... people tell me to burp it... people tell me it's the radiator... I still have no thermo in it, but it seems nothing is circulating except back into the overflow bottle... could it infact be air in the system? I ask this because for about 2k miles i didn't have this issue but then again it was alot cooler out... now in the summer it seems to heat right up after a couple miles of driving....

should i let it overflow and boil out with out the cap in hopes it is air in the system? Or is it in fact a radiator issue.... I don't want to drop 3 bills on a nice radiator, but i heard there are fitment issues with the one from autozone/advanced... any good OEM ones that will go right in?

jakbob

Take the temp sender out (on the back of the head) to burp all of the air out of the head.

What kind of antifreeze are you using?

Running no thermo is bad.

Water pump could still be bad.

Radiator could be plugged.

Lots of things could be wrong.

DUBarado

Yea I know its at the point in mileage (173k) where it needs a cooling system overhaul. I don't believe its the radiator because again when I blew air into the upper hose thru the radiator it pushed fluid into the lower hose and out the thermostat housing where the upper hose was connected. Anyway to test if its the waterpump? Its not even a year old I believe. And as for the tstat, I plan on tapping the burp holes into it then putting it back in since it works fine.

Im just wondering if anyone else had this issue where all of a sudden they realize the coolant not circulating, no coolant in the upper and lower hose, and the upper hose is ballooning out from the pressure.

Id hate to sound cheap but im trying to do this repair as cost effective as possible. If I can get another winter out of this xj before I can opt for a newer one to lift that'd be awesome.

Thanks!

BigBear

I got mine off of ebay for a really good price well under $200 I think I might have paid like $160.

jakbob

Why cheap out? Renix last a long time if you maintain them. You atleast need to replace the rad hose, check the water pump, check your pressure bottle, replace the thermo.

Just check everything. My renix is at 407k miles. Runs like a top.

DUBarado

The radiator hoses need to be replaced. Checked waterpump by disconnecting the hose at the tstat housing and starting it and it spewed coolant all over the driveway. Oops. The bottle is hold pressure very well and is the 3rd one I've had in it. 1st 2 bottles stripped out. I know these things run forever. But im not sure how to maintain them. And unfortunately I can't exactly make a mess of coolant in my complex's parking lot. What I mean by cheaping out is not tricking it out with a radiator that's worth half the vehicle. I just want it to run properly.

jakbob

You need to check the impeller. Just because it spews doesnt mean its within tolerances. You dont need a tricked out radiator either.

What i do to burp it sometimes is let it heat up with everything closed up with the heater on, then loosen the cap till i hear the air start to come out from the coolant system to the bottle.

DUBarado

i burp mine the same way, but to no avail, the hoses are still empty and it seems to just fill up and never go out the bottom... I can only believe the radiator is clogged up... it says modine jeep on it, and FYI theres no fan shroud which could also be an issue with these hotter summer temps.... how much would repairing the system be? Im just weary of if it's worth to keep fixing... i got it in rough shape and fixed it up, but with my new residence, i'm limited as to what work i can do on my cars as per the lease agreement