Donaldio1

Hey all. I have a 96 Sport automatic (OBD I) on 33's with stock axles/gearing and have been having overheating issues. I know another overheating post but seems like I haven't seen this symptom in the forums.

Problems start when I go up any sort of grade. Temp creeps up to the line after 210 right before the red. Thing is I can come to a stop, shift down to 1-2 gear and soon after taking off ( RPMs around 3000-3500) the Jeep cools way down to 210. Winter time its nots as bad but once its 75 or more outside its noticeably worse. Have changed all my hoses (upper/ lower rad, heater hoses), water pump (Mopar), belt, 3 row Mishimoto Rad with triple electric fan, thermostat, t-stat housing, burped the system. Thinking it might be a blown head gasket at this point or maybe a cracked head? Oil isnt milk shaked with coolant or anything. When burping it though it seems like the bubbles dont stop even after 20 min. Also the upper radiator hose is soft enough to squeeze, even at temp.

lawsoncl

Torque converter locking up? If you hold steady on the highway, and lightly tap the brake pedal with your left foot, does the rpm jump up a little? If it doesn't then the torque converter might not be locking and generating extra heat in the radiator.

Donaldio1

Haven't heard of this before ill check it out, thanks!

Sirsyc0

Did you have this issue before that radiator and fan set up? How hot is it actually getting? You can’t count on that gauge. What temp are your fans turning on? Have you checked the sending unit? Have you tried the factory fan set up with that radiator. Did you flush the radiator before the install? Mishimoto radiators are known to come with aluminum particles in them that cause clogs.
IMO the easiest way to burp a system is with a coolant funnel.

Donaldio1

Yeah I had a 10 year old Napa radiator before that and had the same issue. Ive changed the temp sending unit with an aftermarket and it seems to hit the head before it can thread all the way in. Had the stock fans for awhile with the Mishi and same thing. Flushed it prior to install. 2 fans are always on and the 3rd is set to come on around 215. Have it on a switch so if im coming up to a grade ill flip it on but doesnt help. Blasting the heater keeps it from hitting the red.

Donaldio1

Whats a good alternate method to check the coolant temp besides the gage?

Sirsyc0

Infrared temp gun at the thermostat housing. Wondering if it is actually overheating.
At one point I had 32’s and stock gears. I didn’t use overdrive at all.