Hey everyone I just went through the 4 times drain/fill procedure with distilled water to get all of the coolant out of my XJR. I cant remember what the normal operating temperature was and I'm not sure if my operating temp is normal or if I have air in the system... I took a 20 min drive after dark, not in the middle of the day so it was cool out and the coolant temp fluctuated between 204 - 206 for the most part, even while cruising at 50 - 60mph it got as low as 202 for a few seconds then back to 204. I live up a steep hill and as I drove up the steep driveway the temp got as high as 213 then dropped down to 211 after a min then made it to 209 by the time I turned it off and parked it.

Do you think I still have air in the system? My XJ8 doesn't run nearly as hot, I think it stays below 200 most of the time but it doesn't have the big engine that the XJR has so I have no idea.

In attempt to get all the air out of the system I have parked the car on a steep slope several times now while turning the key forward but not starting car with high heat fans on high while squeezing the main radiator hose on the left a bunch of times with the reservoir cap off to try and force the air out of the system. I don't know any other ways to get air out of system and it doesn't appear that bubbles are coming out of it. Heat is coming out of the cars air vents so the heater seems to be working. Does this mean all the air is out of the system and I am running at normal temps or if there is some other issue, maybe a failing water pump?

Any input appreciated, thanks everyone

Thanks guys

 

Sounds fine to me, my XJ8 runs at 203 to 208 depending on engine load. My XKR runs at 205 to 208. On both cars it took some weeks for the residual air bubbles to come through so keep an eye on the reservoir and top it up as required. The thermostat isn't fully open until 201 so your temps are on the money.

 

It tries to run it hot (various reasons). Sounds OK.

 

I don't know what the temps should be but it seems that you have done all the right things to remove any air.

Is the dash gauge reading 50%?

 

Thanks guys... glad to hear that! Yep its holding at 50% just wasn't sure if those temps indicate some air left in system. I took it on a 70 mile round trip today and climbing hills going above 60 it reached a peak of 213 then came down to 211, 209. On the way back at idle in traffic it hit a peak of 213 again but for the most part stayed around 207 - 209 when moving. If anyone thinks this is too high let me know and I will try to squeeze the coolant hoses with heater on with car on a slope to try and get more air out of system.

Much appreciated

 

Ok so I am aware this is an old thread but "squeezing radiator hoses with the car on a slope"? And members checking in saying "yep, your doing all you can to get air out"???

Call me crazy,, but I have never needed to do more than use the air bleeder screw on the expansion tank and perhaps top up the expansion tank with a few ounces of coolant after a few trips.

I had been checking to find normal operating temps for the NA 4.2 liter V8. My numbers never go to the levels in this thread. I see upper 190's with light loads and maybe 202-205 in traffic with front and rear AC cranking- I have the 4 zone climate option. I think if I saw 213 or the 218 reported here I would be concerned.

Any thoughts on temp ranges appreciated. I'm about to do Serpentine Belt, tensioner, idler pulley, hoses and thermostat housing. I have not cracked open the thermostat but fully expect to have to replace the housing. They all break apart at some point and at 102k miles this car has the original t-stat housing. I don't even want to look in there unless I have the part on hand.

What about the water pump? I am torn at the idea of replacing a working pump. Then again if I do the thermostat housing, I will be 2 bolts away from just replacing it. Thoughts?

 

Keep in mind the T-stat is a heat sensitive spring that progressively opens or closes the valve. T-Stats come in various heat ranges. As you have XJR I would think your T-stat is probably a 180*. (start to open temp)