Overheating-Easy fix!

[oshen]

So I thought I'd put this out there.

As we all know, the jeeps love to run hot/overheat. I found highway was fine, just when getting on a boggy beach was the worst.

Now I know the correct way to fix this issue, is to go through all your cooling system. Replace radiator, thermostat, water pump etc.
But there is another way.

Keep in mind my jeeps are just weekend warriors and nothing fancy. But I have done this mod to both now, and it works immaculately. I have a 96 xj and a 96 ZJ. Same motors, but different sized radiators. Both used to run hot when extensively 4wding, to the point where I was running heaters full blast, or having to stop for a few minutes to let it cool down. Since I've done this mod to both, the difference is night and day. The ZJ I did a few months back, and that was the most dramatic change.

FORD AU THERMO FANS. Thats it. I'm running old radiators, water pumps etc, but eject the viscous fan, and add a twin ford thermo in its place, and say goodbye to overheating. The XJ has been running this mod for years now, and the ZJ about 4-5 months.

When I used to take the ZJ down the local, I'd drop to 20 PSI, and even then after about 5-10 mins its creeping over half and into the red zone. After the mods, I went to the same beach and did some testing. In the end, I was running 40 PSI, literally crabwalking to the point of bogging, but still moving. I did the entire beach over 10-15mins like this, I couldnt get the temp to rise over a qtr, no matter what I did. I now generally run only 1 fan, to keep it at a better operating temp, but if it ever creeps up, I hit the second fan, and it stops it in its tracks. Would be good to have it wired up to temp sensors, so it was automatic, but I just have it wired manually to 2 switches in the cab.

Hardest part is getting the the thermos to fit. In the xj, they were about 100mm too high, and the zj about 50mm+ too wide. It just takes alot of cuts with the grinder, and check, then cut again, and repeat. But rest assured, it is do-able. Then I used corflute to seal up any major gaps around the shroud to the radiator, to get a better seal, and more suction.

Both times, the twin thermos cost me $30 from the wreckers. Some extra wiring, some switches/fuses, cable ties, corflute and tape, and I get the jop done in a day.

Before I get flamed for " not addressing the actual problem of where the cooling issue lies".....I get that. If you want to go that route, by all means. I've just seen threads on here on more than one occasion, where people have replaced their ENTIRE cooling setup, and still have overheating problems! After doing this mod a second time, I figured I should put it out there how well its worked on 2 vehicles now, that others with the dreaded issue might want to give it a try.

Heres a link to a thread on the xj install, can probably get photos of the ZJ if needed. Hopefully this may help a few people out, especially if your jeep is just a weekend warrior or bunky.

http://www.ausjeepoffroad.com/forum/...=141856&page=2

[layback40]

Clearly your vicious fan clutch was letting you down. In stock spec a new standard viscous driven fan has several times the air movement of the electric fans you have fitted.

[BLAKLISTED]

Yep, i'll stick with the old school viscous fan thanks. In my experience, seen too many people with thermo's on various makes, not just jeeps, come unstuck when the electronics let them down.

[awg]

Originally Posted by BLAKLISTED

Yep, i'll stick with the old school viscous fan thanks. In my experience, seen too many people with thermo's on various makes, not just jeeps, come unstuck when the electronics let them down.

comments; I am happy to stick with a COMBINATION of VC and electric fan in Jeep, as a new VC is quite inexpensive.

I have not replaced mine, but did put a $100 plastic radiator to replace the split seam brass unit, and it runs quite cool now, ~20min idle in 35C to bring on the 105C Electric fan

Having said that the OEM AU-BA Falcon fans are high quality and known good replacements, used in Jags (to replace single Viscous clutch), & other customs, they move a lot of air, especially at idle. They are easily and cheaply available from wreckers.

So thanks to the OP for posting

to my knowledge, most/all trucks & large vehicles use a Viscous Clutch driven fan, there must be good reasons for that

[emac]

did this 10 years ago, the VC died and i wasn't aware of it, overheated in heavy traffic and then a few weeks later i needed to get the head gasket done, at the same time i had the head services, milled, valve job etc.

now i run twin fans with a thermo switch, they can be switched either by a sensor or separately the A/C, so as the A/C cycles on and off so do BOTH fans.

surprisingly it runs cooler with the A/C on


I've totally removed the boss for the VC and rerouted the acc belt to suit, only down side of this is i don't have a great amount of wrap around for the alternator

and occasionally under load ( lights on A/C on) i get a slight amount of squeal

at low speed, actually it probably needs a new belt

[Jimmyb]

Originally Posted by emac

now i run twin fans with a thermo switch, they can be switched either by a sensor or separately the A/C, so as the A/C cycles on and off so do BOTH fans.

I have a setup the same on the HG Premier with a 400 Chev in it. Has the temp sensor but can over ride it if need be. I set it up this one when the temp sensor failed one day. I even went a step further and put a light in, so that whenever the fans are running, the light is illuminated. Gives me piece of mind.

[LuluBelle]

My entire cooling system is new and the clutch fan electric fan over ride switch and still over 105 at 380 thou ks its off with its head .................
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