mightyjak

Resolved! It was the radiator. Bought a new one, had it swapped out in an hour and flogged it through the hills today. Needle stayed where it should as did the coolant level. Thanks again for all the help.

Nismothunder: had the radiator flushed and filled for the first round of repairs. Coolant mixture should be good. Kind of leaning towards replacing water pump and thermostat as the radiator will be out anyway....

This thing has always been v-e-r-y slow to heat during the winter. Although I have driven it 24 hours roundtrip and had no overheating troubles until now. Think they might be related?

Definite scale in the replacement radiator. I keep finding the radiator low by a quart and I can see some antifreeze around the top. I'm going to pull it and get it tested, as well as replace the upper and lower radiator hoses. After that, on to water pump and thermostat....

It's back again! I haven't driven the truck more than a few miles since I last posted after I had it flushed. I went out today for a drive and it pegged out. Temps are in the high 60s and I was heading up a fairly steep mountain pass when I noticed the temp gauge was pretty much pegged. Turned around immediately and coasted downhill. The temp gauge never dropped significantly. Prior to driving, I had checked all fluid levels, which were good. I noticed the catch can was over the MAX level. To date: I had the radiator flushed a filled and the old man at the shop ran it for 30 minutes on an incline, so I would consider it burped. I've not driven it more than 30 miles in the last two weeks. I figure I'll start with the sending unit since it is easily accessible and cheap. After that, radiator, thermostat and water pump, since if one is pulled the others are accessible. Any suggestions are helpful at this point.... Thanks, Jeff

Got it flushed and filled yesterday and then flogged it through the mountains. Again, temps were a little cooler, but everything seems to be fine for now. Thanks again for all the advice.

BTW, sorry to have asked about the 'burp button'. Thought I had read somewhere about a valve built in for bleeding excess air.

Thanks for the advice, kh1991. I tried the debubbling routine and took it for a test spin at 80 on the interstate. The needle was a little below halfway but it's also about 20-25 degrees cooler than when I drove it last. I think I'll go for the flush and fill tomorrow to be safe....

I hate to sound ignorant, but where is the burp button and what is the burping procedure? I'm scheduled to drop it off tonight for a flush and fill. Thought I may try burping prior.

Thanks for the insight, guys. Tungsten, it's a manual tranny; change your mind any on your prognosis? Guess the deal is this: I'm 230 miles from my tools and workshop. While I can pull the radiator in a hotel parking lot, would there be chance of clearing the clog doing a flush & fill at some shop? I can get the radiator for $120 which isn't bad, but with time constraints and lack of tools a quick flush would be great. The old/new looking radiator appears to be good from the exterior but there's some corrosion in the interior.

Looks like the radiator has been replaced in the past. Did pop the cap off after it cooled down and added a quart or so of H20. Did you guys with similar problems pull and replace or flush and fill at some radiator shop?

I drove my 5-speed '87 PF with 161k miles for four hours from Idaho to NV on a 80ish degree day. Any time the engine was under load (interstate, pulling hill after hill) the temp gauge almost pegged out. While the engine was under less load (downhill and once I arrived in town) the temp gauge dropped to normal. Coolant and oil levels are good and the truck runs great. My first thought was thermostat/water pump, but with the temp drop from highway to town driving I'm starting to suspect the fan clutch. Any thoughts? Thanks, Jeff PS: This thing has always been very slow to warm during the winter. I bought it two years ago from a friend and don't know that thermostat/water pump has ever been replaced.

Awesome! Name, address and a price and I'll send some cash. Thanks for the quick response. You can reach me at jet@adventura.ws

Nunya, any chance you might have found one in your pile? The one I ordered from RackAuto.com is for R side, dealer wants $37 and NAPA wants $34. If anyone has extra, I'm in the market... Hell, I'll even trade you a NEW passenger side exterior handle for what you've got.

Thanks for the info, Precise. I didn't mean to sound off, but I realize my first post sounded like I didn't know my left from my right. No worries! I appreciate you and everyone else helping out.