Hi,
I have a problem with my coolant system. My truck overheats whenever I reach 55-65mph, even when it is freezing outside. Slowing down 10mph always makes the temp drop back down to normal.

I tested my coolant and it only had a 25% charge. I plan to flush it this weekend. What is the best place to drain it from to make sure you get the whole system clean. What else should I look at as suspect while I have the system drained?

I have a 6 1/2 hour drive the beginning of next week!

Thanks
Kyle

 

There are 2 plugs, one on each side of the block you can remove to get rest of the coolant out after the rad plug is opened. One is behind the starter ahead of the block heater,the other is opposite side just behind the filter header.


Just Google................. BajaGringo Block Drains for pics

The block drains are just 1/4"npt pet*****, available in the "HELP" section at the auto parts store. You need a 9/16" crowfoot socket that fits on a socket extension to reach in to tighten them (There's no room for a reg open end wrench). Then, cut up an old spark plug socket to fit over the petcock to loosen/tighten. Once they are loose, slip the 3/8" rubber hose over the end of the petcock and continue loosening the petcock (with the other end of hose in bucket). Intstalling these is still messy and a bit of a hassle, but NEXT TIME it'll be a lot less messy and a lot easier. Smear 'em with anti-seize to make sure they turn 'next time'. I've already had to use mine because when I had the radiator 'rodded' they didn't have the right kind of antifreeze, and I was 200 miles from home. So I needed to re-flush the system and re-DCA it. This makes saving/reusing the expensive DCAs/antifreeze possible if you use CLEAN BUCKETS. I bought a special funnel that snaps into the radiator fill, and use a metal spray paint funnel/filter/screen just to make sure nothing too big gets back in there. Yeah, I'm a little '**** retentive', that's probably why my eyes are brown. BajaGringo
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I added them to mine a few weeks ago(idea stollen from Baja) I confirm they are 1/4" npt pet***** and the 9/16" crowfoot is neccassary also.

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Kennyd
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Get the quality brass pet***** that open fully with a 1/4 turn (twist-**** on the side). There's all different kinds available.

 

I don't think coolant condition is going to give your kind of problem, but it will contribute to excess corrosion in radiator over time so it probably needs to be rodded out and flushed along with the cooling system. put a new thermostat (heavy duty) and proper mix of anti-freeze with distilled water, usually a 50/50 mix will suffice.
most folks here recommend the Ford or navistar thermostat because of bad experiences with aftermarket ones and extra cost doesn't overide the aggravation factor of doing it twice.

 

Is the OE thermostat temp 180 or 190 degrees?Are those of you running svo sticking with the oe thermostat?

Thanks

 

Hi Kyle.. want to share some information with us about your truck.. put it in your signiture.. is it a automatic? turbo or not? Mileage.. how old it the rad and belts.. does the fan clutch work? what kind of load are you pulling anything.. Where are you? thanks

 

Sorry, thought it was showing up.

87 F250, 6.9 diesel, x-cab, 4x4, automatic, non-turbo

I'm in NJ now, headed to VT soon

belts are one year old. Not sure how old the radiator is, It is oem, but looks to be in better shape than most of the other stuff under the hood, making me wonder if it was replaced.

The problem began when I had a canoe strapped to the roof. I didn't have a rack so I used my camper shell and had a piece of foam at either end. The canoe barely hung off either end and because it curved up at the ends this made things a little difficult.
It was about a hour drive and when we got towards the coast it got very very windy. and it felt like there was a ton of resistence. This is when I began overheating. After letting the truck cool down for an hour or so I set off again and it started to overheat almost right away. So I pulled over and let it cool off for a couple hours. During this time I realized that the canoe was strapped on so that air could get right up the front of it and was stuck at the back with no way out. It was acting like a giant sail trying to send the truck in the opposite direction I was making it go. I adjusted the canoe so no air got in at the front and air could excape at the back. I was able to drive the last hour of my trip as long as I did less than 55-65. On another occassion I drove to 8 1/2 hours with the bed fully loaded and the canoe strapped to the camper shell so the air could get through. Again, I had no problem until I reached 55-65. But at 55-65 the needle starts climbing quickly and steadily. Drop down the speed 10mph and it goes back to normal.
May seem like a minor inconvenience until you are on rt 80. And it makes that drive you should be able to do in 5 hours take 7 or 8

 

Check your trans fluid is it burned up? If so your trans maybe slipping also check your clutch fan make sure it is working and there is no blockage in front of the radiator... also the timing could be to far advanced.. not likely but possiable..are your belts tight? or glazed could be slipping at higher speeds.. is it really over heating or is the gage off?

 

I forgot to mention that turning on the heat full blast does nothing to curb the overheating. Only slowing down stops it. I could drive for hours without stoppin doing 45-50. but 10mph more for 2-3 minutes and I'd be in the red. drop back down 10mph and within 1 minute the temps drop back down and are fine again could keep driving for hours again.

 

Have you done a clutch fan test............ email me for info