who has upgraded their '87-'90 to an open cooling system?

[BigOrangeXJ]

I am just wondering from anyone who has converted their older XJ from a closed to open cooling system what the best wat to relocate the thermo switch is. I read this write-up:http://www.bigoffroad.com/bigpages/bigtech/xjfan.htm and it seems like the easiest thing would just be to buy the thermo switch from a '92+ that is meant to go in the thermostat housing and just extend the wires, but then I don't know why the author of the article goes into detail about wiring it up w/ a GM switch and relay. It seems like a lot more work, so is there a reason to go w/ the GM switch and relay, or would using the stock 92+ thermo switch be easiest?

 

[xjwisconsin]

i replaced mine last fall... I ditched the switch completely and have the fan hooked to a manual switch. the PO had rigged it up and felt no reason to change it... I rarely even use it. with the three row, new t-stat and hoses I rarely run higher than 210deg

 

[lumberxj89]

I replaced mine 3 years ago - best thing I ever did! Only time I need the electric fan is when idling for a while - then I switch on the defroster which turns on the electric fan.

 

[XJ&CHZ4ME]

I switched mine out a year or so ago and ran an independent switch through a relay for the electric fan.....has not got above 210 yet and I have abused this thing like Ike did Tina!!! !!!1

 

[Bender]

You could also leave your stock rad in there and put a rad cap inline with the upper rad hose. You can buy the inline cap adapters from any speed shop or online aftermarket part store.

 

[Blue XJ]

You could also leave your stock rad in there and put a rad cap inline with the upper rad hose. You can buy the inline cap adapters from any speed shop or online aftermarket part store.

Thats what I did, bought a nice billet inline filler neck from Summit for $25, grabbed a stock overflow bottle from the junkyard for $2 and some new heater hose. Removed the control valve all together, runs pretty good now.

 

[ptf18]

I converted my 88 XJ after the son ran the Jeep into the back of a school bus...that he was suppose to be riding on....he's in IRAQ now....

Anyways I installed the late model parts and all works fine. I think when I got the thermostat housing I ask the junkyard fellows if I could get the wiring harness from the sensor with as much lght as I could get. I got the pins to mate up the OEM connectot and as I said it works fine

 

[WERBSEN]

Bender or Blue XJ, Do you have a write up or/and any pictures for this inline convertion? I have a 90 4L and would like to get away from the sealed system.

 

[Fred]

I did it quite a few years ago. I used a 3 row GDI with a flow cooler pump. You cannot use a new style sensor, it is a variable resistance, while the renix switch in the radiator is just that, a switch that closes at the specified temperature. I just used an aftermarket temperature sensor/switch.

I don't think it works as well as the stock system did. I installed a two row radiator from Performance Radiator in the 88 MJ with a cheap pump, it cools better.

If you are not having an issue with the plastic tank, I'd just fix the closed system.

Fred

 

[outlander]

Bender or Blue XJ, Do you have a write up or/and any pictures for this inline convertion? I have a 90 4L and would like to get away from the sealed system.

here ya go:
http://www.naxja.org/forum/showthread.php?t=920779&highlight=poor+mans+cooling

It doesn't cost that much at all....

 

[Blue XJ]

Bender or Blue XJ, Do you have a write up or/and any pictures for this inline convertion? I have a 90 4L and would like to get away from the sealed system.

No write up, but I'll give it a shot and I'll go take a pic real quick.


I converted to the open style because I could not burp all the air out of the system after I replaced the radiator. I spent almost a year trying to burp it and never could.

I cut the upper radiator hose in half (and it was empty) and I installed an inline filler neck from SUmmit Racing.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=CSI%2D971&N=700+0&autoview=sku

Then I removed all of the heater hoses, heater control valve and pressure bottle and replaced them with a hose that runs from the thermostat housing to the inlet of the heater core and one that runs from the water pump nipple to heater core outlet. In these hoses I installed the Prestone heater flush 't' fittings to help burp the air.




I then got an overflow bottle from the junkyard, I think its off a 94 or 95. I ran a 3/8" hose from the inline filler neck to the over flow bottle and filled up the bottle. I ran it with the radiator cap open and the t fittings loose and all the air came out. Its been running good ever since.

I have noticed no side effects to removing the control valve, the heat was always poor, now it is better, however it was warmer out when I did the conversion.

Total cost

Filler neck - $28
pipe nipple - $2
5 feet 3/8" hose - $9
6 feet of 5/8 heater hose - $17
overflow bottle - $3
2 flush 't' fittings - $4

total - $63

Here is a pic of the finished product, ignore all the wiring mess, its a work in progress.