Status check.

Just wanted a status check from folks.

137k 40 cold psi oil 20 hot.
High speeds normal driving 195 high demand jumps up to 210-215. No ac
Normal driving 195-210. High demand jumps up to almost 230-240. Cools down when I stop stopping on it.
High demand is me bombing my way through the mountains in PA at 70. Constantly having to downshift to accel.

Idle no ac fluctuates. Creaps up to 210 then the fan will kick on, and it will fall to 195.
Ac 195-220 depending on ambient air.

Idling with ac on in 90ish temps the hood is stupidly hot, damn near burned my fingers trying to open it to jump start someone. (Hoping vents will help)

Roughly 200 to a tank at highway.
Stock towing package I believe. Factory hitch, aux trans cooler, limited slip.

1994 2dr auto 30's 3.55 3".
Thanks chris

12 miles to the gal is not right.

I do have a slight exhaust leak, damn manifold again.

The Hood is always too hot, even from just sitting in the hot summer sun it'll try to burn you. Running its normal to feel like wearing gloves is required to check it. At least for the early 90s 4.0 we have.
The older 80s with the small v6 is easier to open hot. Even with the hood prop positioned in front of the radiator.
Sounds like the electric fan is working like it should.

Temp rang except for the 240 spike sound in normal expectations. You might try changing the thermostat and water pump just as part of maintenance. I've used high volume plumbs for the last 6 years, I think it does help cool better. Last pump change was a GMB brand that claims HV it was much more affordable and no issues yet seem to cool like before, some say a regular pump is just as fine. Maybe. I upgraded when the radiator went deciding to do a punch of trouble shooting at once.

Trying to climb can take a toll on heating, depends how steep for how long.

Did you have the limited slip installed? Didn't think that was a option.

The 30 tire are not helping but I doubt doing a whole lot to hurt either, we run 235s on the stock XJ that 30 is just a little bigger.

The mpg is too low, we average 16-18 mix of city and highway, not climbing any mountains either.

Would the exhaust leak be enough to do that?
I would also check if the o2 sensor is doing ok. Those can lead to mileage issues and possible temp if the mixture is off.

Just a few thoughts


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Neither on my Jeeps are getting that hot...it's 102 here today, and 90 to 100 all summer...unless I'm towing a boat or other trailer. My e-fan brings the temp over 220 really fast, so it rarely gets hotter than that. Also, my e-fans are the later curved 10 blade jobs instead of the stock Renix fan...and I have LeBaron hood vents

Have yo accounted for larger tires in your mileage calculation. May only be a few percent, but it's something. Without correcting the speedo gear my XJ with 31's was about 9-10% off (20 miles in 200 miles on the ODO).

When is the last time you swapped out your fan clutch? If a long time, or never, put a NAPA ZJ HD (not Max Cool) clutch in there, big difference. How old is the radiator? A lower rated t-stat will not lower max temps.

How's the power? Could have a clogged cat causing the slightly higher temps and poor mpg

200 miles to the tank has been caculated off of a known 300 mile(gps) distance between ohio and virignia. i usually use about 1.5 tanks in 300 miles.

Cat is only a year old replacemtn put in in 2015 june to pass emisions. not a cheap cat.
T-stat is a stock 195.
radiator, hoses, stat have all been repalced. waterpump and fan clutch are original to my knowledge.
O2 sensor was replaced a year ago because it was throwing an O2 code. i don't remember brand.

hoses and radiator are 2.5ish years old. t stat is less than one year. replaced due to last one failing open.

eghaust manifold cracks where discoved on the top side of the colector where the 2 banks merge. im asuming that that is my leak since i can hear it and i know the colector bolts are tight. (oem replacemant header)
I am using a 99+ intake, cracks were discover when the intake swap was made. mpg readings are from before swap. trottle body was cleaned during swap.
looking to fix the mpg readings for now, i can deal with no ac or maually conrotling the ac to ensure no over heating.