I'll start off with this.

Thermostat, thermostat housing, water pump, head gasket, heater hoses, and coolant are less than 6 months old. Radiator is a little over a year.

Stock fans, runs at 190 all day long, except when I hit the trail two weeks ago, my temp shot up to 230 and I had to bypass the a/c relay and turn the heater on.

So, I made some 1" hood spacers for the rear to prop it up. Then I installed three 1,730cfm 10" electric fans yesterday on a dirtbound offroad fan shroud.

Temp was running at 200 on the 90 mile trip to the offroad park today. Hit the trails and she crept to 230. I have all three fans wired together. I bypassed the relay again with a jumper wire and had the fan running continuously. I had the a/c running most of the time, temp would really come down. Turn the a/c off and it would come down.

So, what's going on? I have the factory tranny cooler in front of the radiator, but it's also still tied into the cooler inside the radiator. Could that have an effect? Oh, on the way home, on the highway doing 70mph, the temp was at 230 with ac on but would come down with I turned it off. I'm a tractor mechanic by trade, and have never run into this problem before. Should I try running two stock electric fans, or keep the 3?

 

R the efans on at 70 mph?......they shouldn' t be. Moving slow (on a trail) in high ambient temp will challenge just about any cooling system, especially the XJs.

 

Half way home they were, the other half they weren't.

Oh, and it's an aftermarket temp gauge.

 

Tall tires, a tail wind, winch blocking air flow can cause issues.

 

33's, not much wind, no winch.

Didn't overheat like this on the highway before the triple Efan conversion. But it did overheat on the trails with the stock fans. It only gets hot on the trails, city or highway driving and it's fine.

 

230° is not that bad xjs run hot mine runs at 210 city/highway and right around 220/230 on the trails and I got the same conversion on mine with the 3 efans and I run a adjustable themp sensor and my whole cooling system is new

 

Maybe your temp sender is giving a faulty reading or not to accurate.. You can get a IR gun and read the temps to see if it corresponds with what you gauge is telling you?

Just a thought....

 

X2 on that most aftermarket temp gages aint 100% accurate

 

Could be the heat from the A/C condenser isn't allowing the radiator to cool as well. You're basically pulling preheated air through the radiator with the A/C running.

 

The A/C condenser can get hot. A restrictive hot condenser can cause some issues.

 

run a cooler t stat...?
got a 160 in mine no issues

 

No. A cooler t-stat only lowers the MINIMUM temp the t-stat opens. Not the maximum temp the engine runs at.

 

Well exactly..
if the coolant can flow at a lower temp, wouldnt it be cooler always?
theres a reason people use to swap them in winter and then again in summer

 

Only if the cooling system can keep it at that temperature. If it can't keep it at 190 when the OEM t-stat opens, it won't keep it at 160 either.

The reason we changed thermostats summer/winter 30 years ago (and not everyone did) is that designers didn't worry about emissions or efficiency back then and spec'd cold themostats. 165 deg was pretty common. Up in the colder climates that produced no heat in the winter so they'd up the ratings for the season. (And block the radiator with canvas or cardboard!)

 

You would think that is how it works, but it doesn't. The thermostat only opens sooner. More coolant capacity is the only way to lower the engine temperature.