Auburnfan25

Ok I have a 95 jeep cherokee sport 4.0, my problem is that my temp gauge rises to almost 210 (about 200) and then drops back to about 160 (takes about 6 seconds to drop) then it takes about 20 seconds to climb back to 200 and keeps repeating itself. Also there is never any pressure on my hoses. At first it would only go to 160 and stay at that so I changed the thermostat, radiator cap and loosened the temp sending unit (only coolant came out no air) well after I did all that today the gauge now heats up to to almost 210 and then drops (as stated above) I also inplugged the electric fan but still does the same thing. I'm never over heating even on long trips but I know somethings not right about it. Plz someone help.

Aaron

XJriot

Could be a faulty thermostat. Some are faulty so Idk. Try removing the thermostat and driving a bit to see what happens. If the temp is good then thermostat issue otherwise time to trouble shoot elsewhere.

Auburnfan25

Well about 3 years ago I was running about 160 so I went to change tstat and there wasn't one in it so I put one in it and it didn't change, so today I changed it again and now its fluctuating

XJriot

Your new thermostat could just be bad and the spring isn't opening at the proper temp. Go exchange it and try another one.

Did you purge the system of air?

Auburnfan25

How do you purge a 95?

Auburnfan25

Does anyone know how I would go about purging it for air?

djb383

Soft hoses indicates a leak somewhere or bad rad cap. Hoses should become firm/hard as coolant temp rises above ambient temp. Verify the fluctuating dash gauge with a infrared gauge pointed at the stat cover. '95 should be self burping as long as the entire cooling system is leak free, proper coolant level is maintained in both the bottle and rad (cold motor) and the rad cap is funtioning correctly (the rad cap has 2 valves and 3 seals).

PNWjeeper

The open loop system that's in your jeep should purge itself, either through the rad cap or the overflow. Just make sure to check you fluids when your engine is cold and fill as needed every other day until they stay stable.

Auburnfan25

Ok guys thanks for the replys but today when I got off work I bought a new coolant temp sensor and changed it afterwards I was holding pressure and running good steady temp.

Thanks again, think imma go ahead and flush it tomorrow its looking pretty brown

AaronAaron

djb383

The hoses still soft when the motor is hot?

Auburnfan25

NA after I changed the coolant temp sensor (for gauge) I let it run and my hoses got tight gauge stopped fluctuating and pressure on the hoses again, I think I've fixed it (I hope) lol