I have a 89 4.0 with new radiator, thermostat and hoses. Water pump seems to be pumping good and I still have 210 temps with a/c on and at slow speeds it will heat up quick. I toggled my fan switch so I can catch it before 218. 2 core with 195 thermo.

 

i just pulled a trailer with my 89 flooring it downshifting to 4th up hills and all and in stop and go traffic and didnt budge the gauge. You guys have some serious issues the factory cooling system works fine functioning correctly.

flush out the block and the radiator with a hose check fins on water pump make sure air is out of the system. it was 92 degrees today btw when i pulled the trailer.

I do have a renix jeep though (89)

 

I have an 89 upgraded to a 2 core radiator open system. New 195 degree thermostat hood vents and it still will run hot. Water pump seems to be working fine, A/C on temp. will rise very quick when driving at slow speed. (trails, stop and go traffic) So when you guys figure out your cooling issues let me know. I have done everything so im STUCK!

 

i flushed my cooling system when i upgraded and replaced therm. I checked the fin on the water pump seems to be just fine. Have no air in my system bled it all out. Through the Prestone fill and flush installed in line. Any other suggestions. By the way sorry about posting the same thing twice.

 

then clearly you havent done everything if you still got issues and i got the same truck as you and my cooling system is all stock. I think A your cooling system is plugged B your fins on the water pump are broken or C your thermostat is stuck closed. D theres still air pockets in your system

matter of fact my cooling system is 60 percent water 40 percent antifreeze
stock cooling system is clearly fine if it works for me.

 

alright then. Well i guess i will start all over and see what i can get done about this problem. Thanks for you help

 

Since it has been getting hot outside 90+ degree I noticed my 95 was getting close to the red (260) and I thought my thermostat might be stuck so I installed a 160 thermo and noticed the temps stay a little cooler but not much.
on the other hand my 88 runs were it is supposed to but the only difference is it has the 190 thermo and 2 electric fans , one is switched with the ignition and comes on when you turn the key. -
so im thinking of installing a electric fan, I used a stock electric fan in the 88 but it dose'nt fit well (it fits but you have to change out the bolts where the clutch fan went and if your motor-mounts are worn it will rub)
I flush and fill my cooling system every year in the spring before it gets hot outside.

I am also planning on installing a new water pump.

 

Mine always stays right on 210, it doesn't yo-yo at all. Never been more than a couple millimeters above this. It would be pretty easy to get an accurate estimate of the temperature if it was above this, though. There's about a 12 degree difference between each notch after 210.

 

Put in a 180 today and it's staying at about 185 in open air and about 190-195 when I'm sitting in stop and go for 2 feet then stop again (gotta love virginia beach traffic ). Seems to be doing just fine and it's running a little cooler than it was with the 190 so I'm happy.

 

There is alot of posts lately about heating up.
I have to ask how many miles are on your radiator?
They develop scale internally and start to block flow. Thus you loose cooling capacity.

I would also suggest for those with ALUMINUM radiators.
BlackMax Its the stuff your A/C guy uses to clean your condensor. It foams up and is acidic so don;t get it on yourself. It will clean all the bugs dust dirt and anything else blocking the airflow.


You can get it at your local HVAC supply house.
Just spray it on and let it set and rinse it out.

Again DO NOT USE ON COPPER! it will remove the paint and start the copper corroding.

Save the extra and go around back and to A/C condensor on your house and spray it down too. You just saved yourself $150 the HVAC guys would charge you to do the same thing.

 

If you plug a scan tool in (to the ALDL port under your dash), the scan tool will show the actual coolant temp and you can see how it yoyos......the factory dash gauge won't, it remains virtually still. Again, not saying this is bad. Normal operating temp has a wide range, especially this time of year, but most factory dash gauges just sit there in the middle, almost motionless, when actual temps can be over a wide range.

 

so I don't know if this was a dumb move by me but when I was 16 I didn't know a whole lot about cars at the time and had a 90 xj. I was having overheating issues and a friend of my older brother (owned a cj7) said he never runs a thermostat during the summer. So i pulled mine out and never had any problems after that. Never threw codes never overheated and ran around 185-190 at all times. I don't see the harm in not having one in during the summer months. i haven't had the guts to do it in my 97 cause i've notice the obd2's are picky as hell but just thought I'd tell you guys my personal experience. If you do pull it out don't forget to put one in come winter time though. Now all you glorified mechanics bring it on and tell me how stupid i was lol. just kiddin IMO the thermostat just doesn't matter that much in the summer I did it for three years and my jeep ran great.

 

It has to do with the principle of latent heat. The greater the difference in temperature the faster the heat will move to the cooler area. As the temperature of coolant increases it is less effective at removing heat. So keeping the coolant moving and cooler will remove more heat from the block.

 

on the speed channel ive seen a coolan addiyibe that states it will lower operating temps the sensors on the motor have to get very warm to give the ecm a proper signal also go on power blockty.com and look around for the additive

 

Since we've resurrected an old thread that contains the "myth" saying "coolant can flow too fast thru the rad to properly cool",.......here's another interesting cooling system article stating that "slowing the coolant (flow) down is the WRONG way to go".

http://www.arrowheadradiator.com/14_...utomobiles.htm