Overheating Issue!!!!

[iheartbeams]

Alright i am at a loss here guys, and i hope someone can help me out here!
93 4.0. Just flushed the system, new coolant, new 180 thermostat. And the car still runs hot! I just had the intake manifolds replaced. I am not losing coolant or running low, and the motor is making any noises, and the oil is not milky at all. So i didnt blow a head gasket! This problem is driving me insane though, i have tried everything under the sun. Any ideas on how to make it run cooler? It runs at the A or L range on the gauge, and thats only around town, im afraid to take it out to the desert. Much thanks!

 

[rookieshooter]

When you say flushed out was this something you did or did you take out the radiator and have it done at a shop that specializes in this?
I bet it's your radiator not flowing enough coolant due to a blockage.
I have taken old radiators apart and found passages blocked that no amount of flush would eliminate.
This is not a fix, but have you tried running without a T-stat just to see what happens?

 

[iheartbeams]

i reversed flushed it. No I didnt try running it without the thermostat, cause its a pain to remove and install. Also when i did take it off the thermostat housing was filled with rusty gunked fluid as if coolant wasnt passing through it, but i know that there is no way the coolant wasnt passing cause the car wouldnt of made it very far that way

 

[StryctNy9e]

No weird or unusual noises from your water pump latley? I would take the upper radiator hose off and lower off also, then hook my hose to the upper to make sure water is flowing all the way through the block and out the lower hose. Also do this with the heater open and closed so the water goes through the heater core. That should help narrow down what the problem should be. Maybe it is some kind of internal water pump failure, but I would start with the hose. good luck.

 

[SoNic67]

Wanna see my water pump on a Mercury Sable that was overheating similary?

 

[Anime]

You have to be kinda careful with the cooling system, since it needs to be bled/burped when refilling, otherwise you get air trapped in the system, and it can keep the coolant from circulating, when then overheats the engine.

Also, when the engine overheats, or even just gets slightly hot, it damages the wax in the thermostat, which is what lets it open and close to keep the engine temp in check. When the wax is damaged, it usually results in the thermostat being stuck closed.

So it's more than possible to have a clean new cooling system, refill it without getting the air out, then have it overheat right after and damage the thermostat.

The procedure, according to the factory manual, is to first refill the system until the coolant is a few inches below the filler neck, then put the cap on, but only tighten to the first click, not the second click, which completely seals it. Then run the engine for a few minutes, slowly remove the cap, and add coolant again until it's a few inches below the filler neck. It can help to do this once more. Then with the cap on the first lock again, start the motor, move the climate settings to HEAT and turn it on high, and run the motor until the temp gauge goes up to the middle and goes back down, indicating the thermostat has opened. Obviously, if it keeps climbing, shut it down before you overheat it. If the thermostat opened, top off the radiator again, turn the cap to the second lock to seal it, and fill the coolant reservoir to the fill line with the proper coolant/water mix.

I'd also suggest a 190/195 degree thermostat. 180 degrees is too low, as newer motors are designed with higher operating temps. Forcing them to run cooler with a lower temp stat acutally makes them run less efficiently, giving lower mileage and less power.