My dad own a 1996 E-150 with the W351. The thermostat stuck a few months back and caused overheating, and without notifying me managed to damage a head gasket. A few buddies and myself decided to make this a project and do a complete rebuild.

Anyway we have the van back together completely now, solved a few minor leaks that we had and today have been a driving it a few days. With temps in the 40-50s, i didnt think overheating would be an issue. So over the last two days ive watched it go thru heat cycles, watching the temp gauge drop a little to show the thermostat opening ect. So today i decided to take it on the highway, and gradually over a few miles the temp gauge went up, and continued to until i got off the highway miles down with the gauge between the A-L of "NORMAL", so about 3/4 of the way.

Now i know this isnt overheating, but its definetly hotter than it ran before, and im thinking with more miles on the h-way, it would have kept going up. So i got off the highway, and it gradually cooled down and i noticed the heat cycles starting up again, and operating normal. Then back on the highway and same thing, temp back up. I got off the highway to head back to the shop i work at to check for leaks and on the way the temp dropped some, but not all the way back down at a little under half way. Then after parking and letting it run, the temp went back down to normal and is cycling back and forth now completely normally. I am totally stumped, and im praying to God this isnt another breach somewhere causing air in the system.

BTW-the heads were decked ect at machine shop, also we did complete bottom end rebuild. Also replaced water pump.

Any questions to assist in helping, please ask.

TIA
Dan

 

Ok so i wrote that a few days back, and i have an update from today, ill post that here.

Scanner hook-up UPDATE:

So i brought the van up to work today to hook up the scanner and go for a run from there.

So i drove up to work thru traffic, about 5 miles and parked the van and let it run. It ran for about 5 minutes while i went and got the scanner, after hooking up it read 194-195 for temperature, perfect.

So i started moving and it slowly made its way up gradually to about 201-203 after a few miles, thats only expected. So now on a busy street for a lil bit before the highway and it made its way up to about 212-213. Got onto the highway and watched carefully.

After a minute or two it went to about 219, sat there for a mile or two and then started to flicker between 219-221, until finally stopping on 221 and spending the next few miles there. then flickering 223, then solid, then 225, solid, 227, solid. Oh boy. I decided i was going to get off and turn around, and see what happens. Right before i got off the highway it pegs 231 and im not happy. Current speed was at 67mph and timing was at 32 degrees according to the scanner.

So off the highway with the heat on, temp drops to about 226 and stays there till making my way back on the highway. With the heat full blast, i pulled the temp back down to about 219 in a relative hurry, it holds between 217-221 with the heat on. So at this point im eliminating getting air in the system (ie cracked head gasket, cracked head ect). So then i shut the heat off, temp goes back to about 226, then a mile or two, then 228 another mile and back to 230. Damnit, i decide to turn the heat on and watch it again. Within just a few miles, the temp now drops to about 215-217, which as far as i would think, would be normal without heat on.

I get off the highway with the temps at about 220, turn the heat on and help it cool. Now on regular street driving again it slowly creeps back up, not above 223, but higher than 212 like it did before. Heat on full charge, temps drop to 199 before parking it again, now this is weird: after parking and letting it run a few minutes it warmed back to about 210. So basically after a highway trip it wont keep itself cool at a stop like it did before.

Ok guys, i tried to explain that as well as possible. Please if u have any insight please help, im at a total loss here.

Any questions to help let me know please.

Dan

 

Did you install a new radiator or have the old one worked on? You installed new upper and and lower hoses also?

 

You didn't by chance forget to put the spring back in the lower hose did you? How about the engine timing? Since you did a lower end rebuild by chance did you also replace the rings? A new ring rebuild will cause the engine to run tight for a while which can cause a rise in engine temp until things loosen up.

John

 

The radiator is about 2-3 years old and we removed it and flushed it ourselves every which way. The hoses for upper and lower are new, along with the lower straight from Ford with the spring in it.

The timing is weird. When the SPOUT is pulled, the timing is perfect, from when we set it, but when the SPOUT is in, the timing appears to be about 7-8 degrees advanced. It says the timing is not adjustable, and computer controlled so i dont know there.

The bottom end was rebuilt with new piston rings on a fresh hone. I pulled the t-stat last night and im gonna throw a new one in for the hell of it, and drive it some more. This is so aggrivating it makes me sick.

Dan

 

Spout connector on the distributor is supposed to advance the timing, it sounds like your is working fine. You might be on the right track with the thermostat change. You did mention that you had some concern over a possible air block. I would think that should be out by now but just in case you can pull the upper hose to the throttle body and see if you get coolant or air. Highest point on the engine and when I refill coolant after a draqin and flush I disconnect this hose and fill until coolant comes out. I think I read one time in a Ford shop manual about using this procedure.

Good luck

John