OK so i have two issues. 1) my jeep does not run a constant temperature when it warms up it will go to 210 on the gauge and the suddenly drop to like 150, and it repeats this many of times while driving! Is that normal? I will included that there is a new water pump, new radiator, new thermostat, and i flushed the heater core. Problem 2) The blower only comes out the defrost vent no matter what i have the heater set on, I'm glad my window defrosts but id like to get some of the heat as well.

Any info would help. Thanks

 

1.) air in the coolant. Burp it.
2.) Vacuum leak. Check from the canister ball on the passenger side front bumper back.

 

I habe the same problem with the heat just on defrost. Getting ready to fix it by replacing the line. does anyone know the size of that line?

 

Ok what would be the best way to burp it? This is the fist vehical i have owned with the closed system and so far i hate it.

 

It most likely is an air pocket in the coolant but it could also be that your gauge is off. Make sure you verify with either an infrared thermometer or a mechanical temp gauge of some sort. Just tracked down this issue on my '87

 

gauge movement-thermostst opening ang closing,vents-vacuum leak in vacuum storage system

 

I've got a similar temp situation with my 90. I think it's the new T-stat I just put in from O'Relies. T-stat housing stays allot at 150, 160, but sometimes driving the heat kicks up. Going OEM T-stat...soon.

 

Ok so could someone tell me a good way to burp the system?

 

Mine seems to work out naturally. I just top it off for a day or too.(cold) Never seems to need much more. I've seen you can park it with the nose up and undo that top hose off the t-stat and fill via the hose. Also I guess with the nose slightly down you can pull the temp sensor at the rear of the head and fill till coolant comes out there. I've never done ether though.

 

Engine cold, nose down a bit, loosen the cooling temp sender at the driver's side rear of the head til coolant flows out. Replace the cap on your coolant bottle with one from Napa for a Volve. Part number 703-1396 IIRC.

I am only buying thermostats from the dealer anymore. I've had 3 Stant Superstats bad right out of the box. Part number 83501426 on the dealer stat.