Venom

Well......... the other day i was driving my 1995 XJ at 65-70mph on the fwy, and the temp creeps up past the 3/4 mark (235) and almost touches the red (It was about 97 degrees outside). A couple months ago, I replaced the motor with a 99k mile wrecking yard motor, out of a YJ, and replaced everything related to the cooling system except for the temp sensor in the t-stat housing. Its got a new water pump, t-stat,and housing, radiator, upper and lower hoses, and installed a trans cooler. (I bypassed the one in the radiator). I noticed since the radiator replacement (this past weekend), that the e-fan does not come on, but I installed a bypass switch a few months ago, and it comes on when I turn it on, but not from the temp. Compression test, and exhaust gas test lead me to believe there are no issues with the head or head gasket.

My XJ's motor is completely stock and so is the trans.
Im running 33/12.50R15's with stock gears.

My buddy has the exact same set up in his 1993 XJ, but the only difference is he drilled a small hole in the t-stat (as a fail safe), and he usually runs just a hair under 210.

I've been scratching my head trying to figure this out, and have come up with nothing. Any help would be greatly appreciated.

Venom

Anyone?

MountiansRcool

33's on stock gears thats ur problem sounds like everything is perfect dont expect it to run perfectly normal when u put bigger tires on... i thought we knew thiss........

RTorrez1

The first thing you want to do is VERIFY the temp with a I.R. temp gun aimed at the t-stat housing.

Venom

I've got a few friends running stock gears with 33's, and they have no problems. We were all running the same road under the same conditions.

djb383

Did u install the new rad before or after the hi-way driving hi-temp?

Venom

I installed it after, and also the trans cooler after as well.
I took it for a ride and it did the same thing.

djb383

Tall/big tires do place extra load on the motor. We know the cooling system is new and the motor is a 99K JY motor. Was any checking done on the JY motor before the install?

Venom

Yes, by the dismantler

djb383

Any idea of what that may have consisted of?

Venom

compression, and check for for exhaust gas in coolant

AVjeeper

Fluid mixer?
I use 70% water, 30% anti-freeze and a bottle of Water Wetter.