Overheating issue- solved
1999 250 sd v10 cc lb 193000 miles
was towing my 6x10 enclosed trailer on a 250 mile trip. im usually real good about scanning the gauges. running about 65-70 in some shallow hills(new 49 to Texarkana) I looked down and the gauge was near the h. pulled over, nothing blowing. proceeded on for another 40 miles to my destination and all was good. when I got there I replaced the thermostat with a new one. upon leaving, same issue. controlling the speed and rpm I could get the temp needle down. arrived at a stop off half way home and got a 180 thermostat and flushed the rad's at a car wash. cooler night I had no problems. leaving for home the next day overheating again. slow down and it would cool down.
got home, no trailer(truck is not a daily driver) and all seemed well. fast forward 2 months and I towed the trailer on a 25 mile trip and got home and truck was smelling and seemed very hot. had the hot smell for a while. I plugged my odb2 into the truck and laptop(first time to check temp) and it was 220!!
Got on here and read a bunch and all pointed to a new rad. about 6 months ago I had replaces all the hoses.
I figures mine was clogged and was just enough to keep it mostly cool but not under a sustained load. I pulled the rad which is real easy. flushed and flushed, ran in an air line to create bubbles and break things up. ran the motor flushing the return on the ground to clean out everything. all kinds of junk in there. I replaced the coolant tank because I could see this was a source of the trash. BTW I had flushed and changed the coolant 3 other times in 193000. this was the 4th,
took it on a hard drive and it never got above 187 with the 180 thermo. easy driving on the way back it leveled off at 183. when I turned it off it never got above 189.
rad's are only about $220 but a manual flushing may lengthen it's life.
good luck!
What coolant did you put iin it the other times? Did you used tap water or distilled?
I bought mine 3 years ago with 113,000 and now have 256,000 having never maintained the cooling system. I better be ready.
other 3 times was tap water but "soft" water. first two times the gold, last time the green. today I bought the prestone any color antifreeze. it's not green green or gold gold. it's in a gold jug. I think the old bottle flush doesn't work that well. maybe it breaks up the scale but it still has to get out somewhere.
last picture is after a wash...but still clogged inside.



