Hi Guys!

I'm seeing lately that temp rises pretty fast while idling with AC on or off; I recall usually seeing it just above middle marker, perhaps a bit higher towards the 3/4 marker, but these past two days I've seen the needle rise to just below the red marks. As soon as I start driving it drops back to the usual just above middle marker. I've turned off the AC, turned the **** to Hot and cranked it up and not much hot air blows into the cabin -I used to do this on my late 2K2 Discovery S2 when temp went up to try bringing it down- eventually coolant temp drops, but still looks pretty hot. I see no signs of leaks or hear no weird noises. Also, sometimes I do feel the truck would like to stall when coming to a full stop, it is very light, but it's there. I checked the temp readings through my car scanner app, and while running it has gone down to 203°, but when idling it has gone up to 231° approx. It doesn't feel right to see the needle that high. There's coolant in the reservoir, I have not flushed it since I got the truck a month ago. Dunno if it has been running like this since I got it, but I just noticed this in the past two days. I'm looking for tips on where to start and what should be considered regular running temps. From records, previous owner replaced the thermostat back in 2023, and the water pump in 2018.

I'll attach some pics of the gauges and screenshots, thank you all.

 

Check the fan clutch also the thermostat.
You do not want to blow the head gasket.

 

Thanks SKI.DIVE ...drove by my mechanic this morning and since the reservoir was full but saw some tiny bubbles coming up from the bottom he went on to check the radiator ...he carefully started twisting the cap open and let the hot air out. Once it all cooled down he removed the cap and topped off the radiator with nearly half a gallon. He then pulled out the little hose that connects the reservoir to the radiator and blew on it but determined it was blocked and considered it was the culprit or part of the issue. He later told me he was able to clear up the blockage in the hose and some black junk came out of it; since coolant was compromised he recommended to flush the system and go from there. Hopefully the blockage was the culprit and he was able to determine what caused it, but I'll have him check the clutch and the thermostat as suggested. Thanks again.

 

Your first pic is NORMAL. There are a bunch of threads on people freaking out about what they term overheating........ but they do not know what they were talking about. Feel free to look those over.

How many miles?

What Octane fuel are you using when it is hot out?

What is the temp of your Trans Fluid? When was the last time your Trans Fluid and Filter were changed? My guess is your problem is a very hot AT that is taxing your cooling system.

 

Thanks for your input DOC OLDS. Current milage is 168046 and using 87 Chevron Fuel -and yup, is pretty damn hot here in Fort Lauderdale.
I've had this truci for a month now, so replacing the Trans fluid & filter is in my list of things to do shortly, especially since dipstick is broken off from where it attaches to engine, so it is kinda lose in there. I may be doing that by the end of this week or next.
As per measuring the trans fluid temp, if you can shed some light on how to do it, great.
As per the overheating situation, the problem is solved. Apparently the little hose that goes from reservoir to top left side of radiator was clogged. It has now been unclogged, coolant flushed, put a new cap and now highest reading so far has been 210° while parked with AC on for over 15 mins now. Thankfully I noticed it on time and was able to dodge a bullet here. Mechanic tells me some black junk blew out of the tube but couldn't determine what it was. Thanks again for your input.

 

the black junk is probably rotten hose pieces from having old hoses. they deteriorate internally.

 

Let us know what happens, please.

 

With a scanner or Scan Gauge II, or even old school with a physical temp sensor and gauge...

 

Sure, after unclogging the return hose and flushing the cooling system I've been driving with needle right at the middle or just a bit above, so I'm really happy that I got that looked at and taken care off, even 2 days after I first noticed the needle way up there, so I may have dodged a bullet here. And although some may say this truck runs hot and it's fine that needle goes that high up, it doesn't hurt to have it checked. In my case, it seems to have been that clogged up return hose the culprit. Hope this info helps.

 

Thanks DOC OLDS, will check my scanner for the feature and hopefully it has it.

Anyways, moving down my to-do list with this recently acquired truck, I will be replacing the Transfer case dipstick tube next week since the the attachment to the engine is broken, and it is lose in there; at which time I will also have replaced TC filter and fluid since I do not know when it was last done.