Not really a tech question, just more of a looking for general info type thing, so I'd appreciate any help here.

I put a new radiator in last fall and engine temps stayed pretty good below 210(I'd say the 200 range) all last fall and all winter. This summer, I noticed it won't hold that temp anymore. Perhaps just due to hot weather but I'm not sure. She runs pretty solid just below 210 up to 65 on the highway. once I hit 75 she goes to 210 and hangs pretty much right there. My understanding is this is normal. My issue has been running around town. Today, I got slowed in some traffic, and stuck at a few stoplights for a minute or two. Temps crept up to about 215-220. If I got back on a good run it would go back to 210 or just below, but as soon as the stop and go started it went back up. Driving she maxed out to around 225(think walmart parking lot). Is this normal in your guys' experience? when should I really be worried?

Now secondly as I was concerned I parked and shut the engine off. I turn the key back over to battery and the temp rose all the way up to 235(the last line before red). Is this an issue or is this of no concern since the engine wasn't running? Any insight into this would be much appreciated. Also how accurate is the temp gauge in an XJ to begin with, let alone a 15 year old one? Sorry for the long post but I am a worry wart when it comes to this sort of thing :/

 

I was having the same problem when I moved down to Central California in the middle of the summer. VERY hot that time of year, there. I replaced my stock POS radiator with a CFS 3-core radiator and replaced the stock 195 degree T-stat with a 185 degree T-stat. I haven't had it go past 210 degrees even in the hotest part of the summer even after hours of creepin and crawlin trails, since. Normal driving while on the road it never passes 185 degrees.

 

One question I have for you, do you know if your auxilliary fan is coming on and working like it should??

 

Ah, I do know that it is not coming on. It works, but it only runs when there is coolant in the A/C system and I have a leak somewhere and that is preventing the electric fan from kicking on. I'd love to have this fixed, the problem is I'm broke, I just had the rear end redone, as well as new front brakes...

 

Well!! That is a very big part of your running hot problem, then. It's really easy to do a temp. fix in it to make it run until you can get your A/C fixed. Just hook it up to a toggle switch on your dashboard. when the water temp. starts to creep up. Flip the switch and turn the aux. fan on.

 

Yeah, I had my fan out last Sunday and I let it idle for about 10 mins charging the battery and my coolant overflow tank overflowed with boiling coolant... The fan is very important