hey everyone, ive been having some over heating issues on my 94 F350 dually, 5.8L auto. ive been having what i originally figured to be two different problems, and now im finding that i was right. around the same time (a last summer) i began having over heating issues, that slowly got worse, i tried few small things here and there, everything seemed to work for a short time then the problem would arise again. last fall the exhaust manifolds began getting red hot occasionally (seemingly only if the engine got hot too) and they would actually melt my spark plug wires, which is how i knew. not to long ago i ended up finding a clogged radiator, so i replaced that. that seemed to fix the over heating, but just as i suspected, the red hot manifolds were being caused by something else, because they got hot again, but the engine didn't. my cat is already gutted out (lol) so dont waste your energy typing that lol.

could it be timing? what should the timing be set to? right now i think its at 0 BTDC, or very close. also note that this truck is definitely built as a flat land truck. im not sure whats in the rear end, but its very slow, and its used as a work truck towing occasionally, and in central pa where there are hills. when towing is more specifically when it will get hot. i understand it just might not be made to handle the heavy work load well, but i would think that being an F350 it should be ok. my heaviest trailer is probably my garbage trailer when it is full, 5-7,000lbs.

any suggestions would be great. thanks!

 

Running rich, or timing is off. Does the exhaust smell like fuel vapor?

 

Timing at 0*? That isn't good. Pull the spout and recheck it, should be around 6-8* for stock. Most bump a couple degrees if you run better fuel(keep from knocking under load).

How's the cats? could be plugged also after running it so hot for so long.

An F350 with only a 351 will NOT will any pulling prizes. Never knew why they offered that motor in a one ton? Definite grocery getter, not a trailer puller. It should pull a 5-6K trailer without issue, but depending on gearing is how well it does hills.

 

Timing should be 10* with the spout pulled. Get that corrected and see if the problem persists.

 

Yep!! The timing is 10° BTC (factory spec) with the spout connector pulled!!! If it is actually at 0° I'll bet it really is a dog.. You can get better performance by going to 12° to 14° as long as you don't run into a pinging problem accelerating or pulling hills, if you do back it off 1° or 2° at a time until it stops pinging..

 

what is it with the spout conector still connected?

 

and also does the motor run better with the spout plugged in or un plugged? sorry for thead jacking just trying to gain knowladge

 

I would be led to believe that if it were @ 0 BTDC, his manifolds wouldn't be running red hot. When I rebuilt my 302 last year, initial timing was @ 2 BTDC and it ran crappy and sluggish till we began to turn the distributor towards 10. I just base that knowing that the higher the base timing is, it's gonna advance it further with the spout connected. 16 BTDC is gonna stretch the limit of detonation and pinging. This almost sounds like a running lean situation. Have you checked for codes? What is the condition of the plugs and electrodes? What are the plugs gapped at?

Have you checked fuel pressure? When was the fuel filter changed? Let us know what all has bee checked in regards to my reply and maybe we can give you some better diagnosis's.

 

ok, spout connector, thats the the connector off the distributor?

 

Variable--determined by the computer advance. That's why the SPOUT connector needs to be pulled to set the base timing. Doing it any other way is an exercise in futility.

Jason

 

It's a jumper, located on the driver side fenderwall, near the TFI module. If this grey or black connector isn't removed before checking/setting time, it pointless, as stated by jroehl.

 

ok cool. so after timing is set, plug the spout connector back in?

 

Yes, the reason it is pulled is to disable the computer advance.. With the computer trying to adjust it you would NEVER get base timing set right..

 

ok awesome. thanks guys! ill let you know how it goes

 

I agree with timbersteel about the timing not probably not being what causes the manifolds to get so hot, BUT, it may make it easier to find the actual cause if it's not fighting the timing issue..

I would look for a lean condition, vacuum leaks, possibly an intake manifold leak (bad gasket, loose bolts)

If you have a non contact laser thermometer you might try checking the exhaust manifold right at each port and see if they are all about the same temperature, if you find one or two way off the average reading it might tell you which cylinders are giving you the problems.

I think the question has been asked, but have you checked the KOEO and the KOER diagnostic codes? That can tell you a lot about whats going on if it has stored codes...