I just pulled out the thermostat on my 89 and at the bottom it says 160F and my new one is 195F Do I need the 195F or the 160F thermostat if the old one (160F) is bad?

 

Stock is 190 to 198 I think it is.
I typically use a 180 without issues.
The hotter thermostats are to make the engine burn cleaner to pass EPA regulations.

 

Damn it idk what could be cuasing the overheating then. I flushed the radiator. Do you have a picture of how the thermostat is suppose to be placed in the engine?

 

As long as you put the copper end, towards the engine its in right.

the pointed end points to the radiator.

Have you cleaned the radiator externally?
I use to use some stuff called Black Max for cleaning A/C condensors but since its hard to find. I would suggest spraying it down with something like Easy Off Oven Cleaner and then wash it off and flush all the dirt with a hose.

 

What is your temp gauge reading when you notice the rig start to overheat. Im having a similar problem with coolant boiling out. Did flushing your radiator help any?

 

The engine will reach the same temp it normally runs at with a 180 or a 195 t-stat , the 195 will bring it to operating temp faster by restricting flow that is all.

 

Factory t-stat is 195F and the t-stat only controls minimum operating temp, nothing else.

 

YEA, what he said!

 

I put new one in. The need is between 210 mark and the next white mark before red line.

 

So after the new thermostat your running at about 220F then?

 

No before idk about new one I had to drain some of the new radiator fluid out so I am getting more tomorrow then trying it.

When I flushed the radiator since there was some water in the block he said just get full concentrate and since I don't know how much water was left in idk how much to mix in so I just added the coolant without adding more water. Could that be the cause too?

 

Too much coolant can cause the engine to run hotter, water absorbs heat much faster than the coolant, but you need the anti-rust and lubricating additives in the coolant keep the system alive longer. A 70% water to 30%coolant ratio works great depending on where you live.

 

If you live in colder climates 50/50 mix is good, too.

 

The XJ cooling system holds about 3 gals. When the system is flushed and drained at the water pump, about 1 gal of water remains (unless u drain the block). When refilling the cooling system, add 1 gal straight antifreeze/coolant 1st (presuming block is not drained), then fill it up/top it off with 50/50 mixed coolant/water.

 

I just feel like draining all my coolant out and re filling it.