last time i posted i had issues with lack of power in my truck. turns out when i changed to plugs/wires/dist cap/rotor, one of the wires slipped and got melted by the exhaust manifold (those aftermarket wires are super long). i got that squared away, the truck runs smoothly here at sea level. we got so excited that we decided to try to go up to the eastern sierras. once we were up to about 1000 ft elevation, the truck started to loose power again, and overheated. we stopped, let the truck cool down, tucked our tail between our legs and headed back home, at which point the truck felt good again.
it was a hot day (90's) and there was a lot of traffic, but the overheating didn't happen until well after the traffic cleared up, but just at the end of a long incline.
the coolant level was good when we left, it's nice and green, but it does smell a little funny. should i flush the radiator and try again, or is there something else i should be looking for?
thanks in advance.

 

Which aftermarket wires are you referring to?

When was the last time the radiator was flushed? If it was recently, there may be air in the system still.

 

aftermarket spark plug wires are really long. especially the one that got melted.

i haven't flushed the rad. but i think i'm going to do it today. what do you think of those flush kits?

 

i'm really curious about the radiator flush kits you can find in auto parts stores. my chilton manual does not make mention of them, but the mechanic behind my parts store suggested i use it. does anyone have an opinion regarding these?
thanks,

 

Im not really sure whats in a flush kit? All you need is new coolant and a few buckets to drain the old coolant into. Thought that was pretty self explanatory.

 

flush kits usually come with a tee that you splice into the heater hose to flush the cooling system with a garden hose.
anyway, i just drained, added flush stuff and drained and filled and drained and filled over and over and over again. i think it took 7 or 8 times (i lost count) to get the drain water clear.
the original point to this thread, however, was to figure out why the truck feels like it looses power at altitude.
does anyone have any ideas?

 

might be time to replace the t stat as well.

 

I meant which kind/brand of aftermarket wires do you have? I would get the Motorcraft or at least BWD direct replacement ones. They fit so much better than the others.

I'd probably go ahead and replace the thermostat with a stock spec one.

I've never really used the flush kits. I think we may have once before on some car we had. I always just drain out the old, and then run clean water through it with it running for a few minutes. Just keep the radiator full of water. After that I just fill it up with fresh anit freeze and some water.

 

oh. i think they were napa wires. got them from lee's auto, the local napa store. i've been noticing motorcraft being mentioned a lot on these forums so i think i will take your advice and change the whole set (i replaced the one that got melted with one that i had laying around).
thanks so much, it's really great to have this resource available. and i really appreciate all you folks taking time to answer questions and help us other folks stay off the side of the road.

 

There's a pretty easy way to find out if you have bad or broken down cables on the high voltage ignition system, simply get the truck somewhere where it's pitch dark, pull the fuse on the daytime running lights if so equipped, pop the hood and rev the engine a few times. If you see a light show either the wires are toast or you simply need to re-route them away from each other or metal parts of the engine.