Topjimmyk

So today i was driving and i noticed my temp was a little higher then 210 and it was like 20 degrees today. and i was cruisen at 55. so i turned my heat on full blast, and it was warm at the most. So i pulled over and there coolent was pouring out of the over flow tub hole near the cap. so i turned around to head home and my heat started to work normal but the jeep was running still running a little higher then 210. so i parked for around an hour and went to get my girl friend about 5 miles away and the heat was blowing cold air and i let the vehicle warm up before leaving and when i got home and shut it off there was a loud bubbling noise coming from the radiator. but no coolent, or wet spots any where. just a loud bubbling noise.
i have no idea wht could be wrong. thermostat??

DIY4luv

Bingo, thermostat

1991Jeep_Man

I would think so. I remember I had a bad thermo, and when I replaced it, they had given me another faulty thermo. Anyway, when I went to "burp" the air and add coolant as needed (open system) at 210 the thermo never opened and the radiator fill hole started to overflow. So I imagine with the cap on it would all overflow into the overflow tank.

Also, not sure about the heater. I dont think the thermo has any effect whether or not coolant flows to the heater core.

Good luck!!

djb383

Running a little over 210 and coolant pouring out.......to me, it sounds like u need a new rad cap and re-fill with coolant. Neck of the rad could be cracked and allowing coolant to leak out.

Topjimmyk

is there a thread on hear on how to do it. i do have a hanes manual too but there not so specific.

1991Jeep_Man

Not that I'm aware of, but it is rediculous easy. Go get a gasket, 195* thermostat, and some RTV from the parts store.

1) You can disconnect the negative if you want for that safety precaution.

2) Disconnect the coolant temp sensor, upper radiator hose, and heater hose from the thermostat housing right on the front of the engine. MAKE SURE THE ENGINE IS COOL! And be prepared for some spillage.

3) Take out the two bolts on the thermostat housing. The top one is the longest, and the bottom one is a PITA with the belt in the way. I just pushed the belt down and worked around it.

4) Carefully pry/pull the housing off the engine. Coolant will spill.

5) Take the old thermostat out and clean both the mating surfaces of all gasket and RTV. Be careful not to scratch the head or crack the housing.

6) Apply RTV in a 1/16 - 1/8" bead on the housing. Make sure none clogs any of the holes. Use the bolts through the housing as a guide for the gasket, and let sit for 1 or 2 mins. Meanwhile, take your new t-stat and put a small dab of RTV on the 12, 3, 6, and 9 o'clock positions on the rim. Dont allow any to get on the spring or it will not open (trust me on this lol).

7) Position the t-stat in place, and make sure it stays. Apply RTV to the exposed side of the gasket now on your housing, and again use the bolts as guides to position the housing on the head. PATIENCE IS KEY HERE. Do not rush it! What I found to work well was use the top long bolt to guide the top, and screw it in a good ways so it stays, then use a small screw driver through the bottom hole of the housing and the head to position it, and carefully replace the bottom bolt.

8) Tighten VERY CAREFULLY! These housings will crack in a heartbeat. Tighten in small increments until they are nice and snug.

9) With the housing back on the motor, reattach all hoses and the coolant sensor. Pop the rad cap and fill with coolant, then start the engine and fiil as the coolant is sucked into the head, and put the cap back on once it stops pulling coolant. You will hear a slight hissing noise, this is normal. It is the air escaping through the rad cap. Watch the temp gauge and make sure the t-stat opens. Then, refill the OVERFLOW tank as needed because now the cooling system will simply draw its needed supply from the overflow.

10) Pop open a beer, pat yourself on the back, and you're done.

djb383

.......and while you are at the parts store, buy and install a new rad cap.