davedude44

Yes thats what im going to try. Should the thermostat still have coolant flowing through with the radiator cap off?

Its weird it gets hot maybe around 220-230 then the check gauges light pops on and the temp gauge instantly shoots to 260 pinned on hot.

BimmerJeeper

Can we summarize (in order) the usual suspects you'd check/replace when overheating?

• Top off expansion tank
• Top off radiator (when cool)
• Replace thermostat
• Check/replace water pump
• Cooling Fan clutch
• New radiator cap (if leaking)
• New cooling hoses (if leaking)
• Blown head gasket (coolant in oil)

How do you "burp" the system?

hankthetank

^^maybe he has a steam pocket stuck in the back of the head. what points to this is sometimes the sudden rise in temp...could be from the possibility of the aforementioned stop leak causing some blockage in the system or a bhg... I would do the ususal stuff first though as mentioned above. my renix has a plug at the back/top of the head...does a 98 have one too?

hankthetank

no. just replace the 'stat and go from there...

davedude44

Here is a pic i took of the oil last night

Will replace tstat and report back later

davedude44

Also some wetness around the valve cover towards the rear of the engine where the smoke had been coming from

davedude44

Just put a new thermostat in. Am waiting for the gasket sealer to dry. I did notice that both of the lines going to it were completely empty. Shouldn't these have coolant in them?

djb383

Absolutely.

djb383

Don't see how it's possible for the rad to be full and and the top hoses empty. Look at the rad cap in relation to the hoses......if rad is full, top hoses are full, simple as that.

davedude44

Full rad


Empty Hoses

davedude44

The top hose is above the fill point. I suppose i could jack one side of the jeep up and fill it that way

BTW I truly appreciate everyone's help!

djb383

Look at the neck of the rad, it slopes back just a tad thus holding a little coolant residue in it (your pic). If the cooling system was full, both of those hoses would have gushed coolant the moment they were disconnected.....if they didn't, then cooling system is low despite that tad bit of coolant in the pic. Trust me, it's a sealed cooling system, no air in hoses, presuming proper maintenance and no leaks.

davedude44

I ended up filling the system up through the hoses and isnt over heating at all now along with the new tstat. Think its time for a complete coolant flush. Get rid of all the gunk in there and stop leak residue.

djb383

Have u replaced the radiator cap?......it's a 2-way valve and has 3 sealing surfaces.....all 5 must function/seal correctly in order for the coolant recovery system to work as it should (continuously bleed air and replace any air with coolant from the bottle so the hoses stay full).

If u filled the system thru the hoses, u definitely have air in the system......maybe not as much as u did have, but u still have air in the system. Fill the rad, leave the rad cap off while letting the motor idle, keep the rad full while letting the motor reach operating temp and the stat opens (cap still off). When coolant/air surges out the rad, install the new rad cap. Check coolant level in both the bottle and rad when the motor is COLD for the next several days.