88jee

Ok really stupid question. So I have an 88 jeep cherokee pioneer, I have had some heating issues ever since I bought it. I have had the thermostat, temperature sending unit, water pump, fan clutch, electrical fan relay and pressure bottle cap replaced plus a couple of flushes, car has a little of 76k on it. In normal driving the car never overheats.I live right by the mountains, and I started to notice while driving I-70 up in the mountains that the car starting to get really hot once again. I had the car downshifted into 4th gear to make it up a pretty steep hill at a reasonable pace around 55-60 mph for about 10 miles and the temp got close to around 245, its whatever mark is before the red, and then I hit some downhills and the car cooled. Outside temp was around 90 degrees. Before I replaced everything it would just go into the red automatically. I know cars get hot going up hills, thats normal, but this seems too hot, I just want to know if this is normal for this jeep, if anyone else gets that hot in a similiar situation. Only thing that has not been replaced in the cooling system is the radiator and heater core. I just don't know if this is normal, I mean I have another car that got a little past the midpoint in the same area but not as hot as the jeep. I am just so tired of running into cooling issues with this car, i feel like if I had gone anothe few miles uphill, it would have gone into the red.

Xj88

When you say you replaced teh pressure cap..did you replace the cap or the entire bottle? I had similar issues on my old 88. 245 is pretty darn hot..I wheeled for about 5 hours yesterday, stayed in 4 hi or 4 lo most of the day, in 90+ degree temps, sometimes in low gear, and sometimes on teh gas pretty good...and never went above 210...granted thats in a 98 xj...but still..my 88 never got above 200 even when wheeling. Normal driving it never went above 180.

88jee

No just the cap, the bottle is not that expensive, probably should have replaced that but when I was doing everything I took it off to clean it out and put some water in it to check for leaks and it didn't leak at all. Do you think it still needs to be replaced?

Xj88

Mine had a stupid small crack on the bottom nipple where the hose fits over it. I got the entire bottle and cap for like 20 bucks at o'reillys.

88jee

You know that could be where mine is. I only notice it when the car is really hot but there is a little bit of coolant that had leaked and dried on the house that comes down out the bottom of the tank. Maybe that's what it is...

Xj88

Replace that sucker!

88jee

Will do, I'll let you know how it turns out!

88jee

When you had the crack in yours, was it overheating? Like mine on the highway?

cruiser54

A real upgrade in a cap is the 703-1396 from Napa. The rest are chinese crap.

88jee

I did some searching on the forum and saw your posts about the cap. I called Napa and I am going to be getting one of those as well. It says its a radiator cap but it fits right on those tanks?

cruiser54

Yes, and it works great.

88jee

Ok I put the new tank on, put some coolant back in and i am going to start it up when I get home this evening. The real test will be going back up in the mountains, I hope that cap and bottle is able to pressurize the system better and regulate the temp. I have never had a car that only gets hot when you are driving on the highway for an extended period. Just doesn't make sense!

Xj88

Thats renix for ya!

cruiser54

None of my three Renix Jeeps do that in Arizona.

I'm wondering if the radiator has a flow problem even though there's not alot of miles on the Jeep.

Xj88

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My renix didnt do that either...I was just hatin on the renix