No More OVERHEATING!!!! YEAH! Biggie UP for BC BLues

[raeuspius]

ALL CREADIT TO: BC BLues

I didn't use the 93' Thermostat housing because my radiator blew up on a Saturday night and there was no place to get it today. Nor did I get the aftermarket resivoir. Luckily the one I have is miricalously in great shape. So I overflow out of the 5/16 outlet on the fill hole of my new 92' radiator through the bottom of my resivoir.

I did mine today on sunday for about 225.00 and about 3.5 hours before I started up to get warmed up. NAPA is closed on sunday so I had to settle for autozone and advance for the:

Radiator (129.00), heater valve (16.00), Temp Switch (16.00) and other below mentioned items.......

I flushed the heater core while on step . This is a must!!!! wait til you see the shyte that comes out.

After two hours of idle My TEMP gague doesn't even come close to 210 for two hours of idle. My heat actually works too. I still want my fan to kick on at a lower temp so I will have to continue with the Thermostat housing part in a week or so.

Thank you BC BLues!

ALL CREADIT TO: BC BLues
"BCBlues
For all of you that have a pre 1992 Jeep Cherokee with 4.0 Ltr 6cyl engine. I have the solution to your cooling system wows. My Jeep Cherokee is a 1988.
The stock Pre 92 system is a closed system with no radiator cap and complicated plumbing for the heater core and the coolant expansion tank.
The problem with the system, as I'm sure your already aware.
1. The coolant expands and blows out of the expansion tank cap with no place for it to recover from.

2. The electric coolant fan switch is in a bad location and rarely turns on the fan when needed because of constant coolant loss leaving the sender un-exposed to coolant, and its location in the radiator is a cold spot because of the design of the radiator.

Remove the original radiator and replace it with a Modine NAPA # 2802 or equivalent. This radiator is listed for a 1992 Jeep Cherokee. This radiator is an open system exact fit and has a radiator cap/fill neck. All hoses and transmission lines will connect in the same place. This radiator does not have a provision for the fan switch (I will get to this).
The proper radiator cap for this unit is NAPA #705-1445

Remove the water outlet (thermostat housing) and replace it with the housing from a 1993 4.0 6 cyl Cherokee. This is a dealer or auto recyceler item. This housing is an exact fit with all of the hose positions in the same place. In addition this housing has a hole tapped into it for the 1993 temp gage sending unit. This is were you will mount a Fan switch to replace the one that was on the origional radiator. This new switch location has better heat transfer to the switch so the electric fan will cycle more frequently thus resluting in better cooling.
Since you have the housing off this is a good time to replace the thermostat.

You will need a Fan switch. I used NAPA # FS113, and the proper connecter to this switch is NAPA # FSC10. This will turn on the fan between 207-220 degrees. The origional radiator mounted switch activated at 230 degrees. As mentioned earlyer the new fan switch mounts in the 1993 thermostat housing.
The switch is a single pole switch with one wire and switches to ground so you will have to use a head light/horn relay to connect it to your original fan wires.

1. Run the new fan switch wire to the ground terminal of the relay.

2. Carfully cut off the original wires with plug from the original radiator mounted fan switch. Cut them off at the switch side so you have the plug with the wires attached. The yellow wire is +12V and the black wire goes to the original fan relay. Connect the wires with plug to the switched (load = yellow, output= black) terminals of the relay. Since the yellow wire is hot +12v when the ignition is on use this wire (make a jumper to connect to the + side of the relay) to power (activate) the relay.

Recap step 2. Yellow wire goes to relay + (positive) and relay load terminals. Black wire goes to relay output terminal. Fan switch goes to relay - (minus /ground) terminal.

3. Remove all heater hoses, coolant expansion tank and mount, metal y-pipes, and heater valve if your model has one. Be carfull not to break the plastic vacume line attached to the heater valve as it can become brittle.

4. Install heater valve NAPA #660-1174. This valve has 4 connections. Looking at the valve from the opposite side from the vacume switch with the curved end of the valve facing upward you will see one connection facing forward, two connections facing back and one facing at a 45 degree angle facing towards you. On the bottom angled connection run a 5/8" heater hose to the thermostat housing. On the single connection on the front run 5/8" heater hose to the water pump. Connect the two rear facing connections to the top and bottom connections of the heater core. Connect the vacume line that was connected to your old valve to the connection on the new one.

5. Purchase an after market coolant recovery tank and mount it in the hole were the old coolant expansion tank/mount was removed from.

6. Run a 5/16 fuel line or equivalant from the expansion tank to the fitting just below the radiator cap.

7. Fill cooling system using standard methods and precautions.
Parts list. I used NAPA auto parts as a source so all part numbers are NAPA numbers. These are standard replacement parts and can be purchased from any after market or dealer source.

1. Modine Radiator # 2802 for 1992 Jeep Cherokee.

2. Radiator cap #705-1445.

3. Coolant Fan Switch # FS113.

4. Fan Temp Switch Connector # FSC10.

5. Heater Valve # 660-1174

6. Water outlet from 1993 Jeep Cherokee (dealer only or auto recycler).

7. Standard 30amp Headlight/Horn Relay.

8. 8' 5/8" Heater Hose.

9. 10' 5/16 Fuel line.

10. Teflon tape or equivalant thread sealant for Fan switch threads.

11. Small roll of 12 gage wire.

12. Small package of 1/4" spade connecters to connect wires to relay terminals.

13. Small package of butt connectors to connect fan switch to wire going to relay.

14. Two gallons of Antifreeze/Coolant.

You will now have a standard open cooling system like every other car on the road. No more will you be stuck on the side of the road with an over-heated Jeep as the result of running out of coolant because of the Renult designed closed cooling system. When you add coolant to the new system you will know that your radiator is full because you fill the radiator now, and you now have an overflow tank that will return the expanded coolant into the radiator when it cools down (just like every other car on the road.

This conversion takes about three or four hours depending on your abilitys. Show this list to any radiator shop and they will know what to do if your not a do-it-yourselfer.

The bottom line....This conversion will cost you about $350 to $400, about the same as replacing the origional components, but with the benifit of no more problems and the insurance of not overheating and causing expensive engine damage."

[4x4grey88]

I don't know what happened to your Jeep, but I too changed out my radiator system from the standard 1988 to 1993 (three pass) radiator system. Mine works very well.

Sorry to hear of your miss fortunes.

[raeuspius]

Originally Posted by 4x4grey88

I don't know what happened to your Jeep, but I too changed out my radiator system from the standard 1988 to 1993 (three pass) radiator system. Mine works very well.

Sorry to hear of your miss fortunes.

No.... My misfortunes came the night before I went and bought the stuff. I did the conversion and it is great... I still have to change out the Thermostat housing. I am good to go! hehhe