So I have my 89 xj, runs well, and during normal driving doesn't over heat. BUT I took a trip up to the mountains this last weekend, and it did not appreciate going up the Long hills in 100+ degree heat. It never over heated, but it did get very close, the last white line before getting into the red... I was not running my AC (which really sucked)

It has a new radiator, hoses, coolant, etc. that I replaced back in april.

what other options do I have to improve cooling on the system? I would like to be able to tow a 2500 lbs or so pop up camper behind it, and there is no way I would do that as it currently sits.

 

What does "etc." mean? How old is the fan clutch? Fan shroud intact/in place? Efan turning on?

 

fan clutch is new, shroud is in tact and in place, and the efan is turning on.

 

New water pump, t-stat? Detailing what "etc." means sure helps.

 

just assume all the parts that are associated with the cooling have been replaced.

 

......then just assume u'll have to live with almost overheating.

 

Have you put a new coolant pressure bottle and cap in?

 

- The pressure bottle (plastic bit) and cap should be replaced every five years or so. You can source replacements from Morris 4x4 Center for a reasonable price - getting both in one part number. There are reports from the field that a Volvo cap will also fit - but the pressure bottle itself gets old and kinda brittle, and that can lead to failure with a new cap (because it's not the cap's fault.)

- You don't mention if the system has been flushed recently. If it's been some time, you may need the powdered two-part cooling flush (first is oxalic acid, second bit is a neutralizer. If I do this, I will do a third step - and just hook up a garden hose for 10-15 minutes after neutralizing the acid, to get everything out. Typically, I'm idling the engine with the water running slowly.) The system should be flushed about every five years - so when you change the pressure bottle (flush the system, then change the bottle.)

- Also, how old is the radiator? It's a quirk of RENIX that the OEM radiator will start to 'core clog' at 150-180kmiles - and even the techs at the dealership will use an aftermarket radiator (CSF, Performance Radiator, or Modine - as long as it's all metal.) No-one knows why, which is why it's a quirk (it happens even with impeccable maintenance.) I had a radiator clog up on me at 160Kmiles, and replaced it with an aftermarket Modine. That was 340kmiles ago.

- Doesn't matter what sort of vehicle it is; if it's water-cooled, a bottle of Redline Water Wetter won't go amiss. Just dump it in!

- When you put in a thermostat, drill two 1/16" (or so) holes in the flange, 180* apart, and about 1/8"-1/4" in from the edge. Install with one hole at 12:00 and the other at 6:00. Why? Because RENIX can form a gas pocket behind the thermostat if it's not "burped" properly, or if it gets hot. This makes the system self-purging, so you don't have to worry about it.

- Speaking of: I tend to suggest using a 180* thermostat in a RENIX that does a lot of work - instead of the OEM 195*F. The difference is that the 180* opens earlier, which gets cooling a bit ahead of the game.

I will agree with everyone else that "&c" isn't detailed enough - there's a lot that can hide where you're not looking (heater core, heater control valve, reservoirs, ...) and there's a bit too much ground left open that way. Takes information to get useful information, so try to avoid the use of "&c" when looking for technical advise. That should help keep from getting stuff you've already done, and the details you release that way should help us figure out what you do need...

(NB: RENIX doesn't really care overmuch about operating temperatures, and I've successfully pulled them down from 205-210*F to 180-185*F, with a little work - much of it explained above. No ill effects on emissions, and RENIX doesn't "store" or "throw" codes in the first place. Spec op temp for the 6-242 is 205-208*F, but I didn't like that, and something can be done about it on pre-OBD rigs...)

 

703-1396 coolant bottle cap from Napa.

 

Ugly as hell buts works wonders, fought it for years, the parts guy at Napa looked at me sideways knowing I don't have a Volvo, but it works.

 

Best place to begin. It has solved uncountable issues with the Renix closed system. Thanks go out to my dear friend Joe Peters for turning me on to this.

 

R there issues with "burping" a Renix system?

 

It doesn't require "Burping"

 

If that's the case, then drilling the stat just prolongs engine warm-up, no?

 

No. My 3 warm up quickly with factory stats with the jiggle valve hole.