Hi,
I'm new here and new to diesel trucks. I have a 94 f350 quad cab dually 7.3 turbo automatic. International engine...factory turbo. It is worse than a dog and won't pull itself over 65 and overheats over 55 for very long. Rpm stays under 2300 and it still runs hot. Where do I start looking? 245k miles. Shifts great when cold but weird once warmed up.

Thanks in advance for any info.

 

What shape is your radiator in? Does it overheat at idle? I'm sure that at 245k the transmission is due for an overhaul.

 

Trans was flushed. Temp gauge sits right in the middle at 55 or slower. Won't pull for crap even while still cold, so temp is nit c why. I will deal with Trans issues separately...probably have it done...but want engine to work right first.

 

Cools down at idle

 

Smoke? 10 char

 

Nope. Not at all except when trying to pull a hill

 

And then very little

 

If you dont have a aftermarket trans cooler, the radiator want be able to cool the trans fluid so it might shift funny due to overheating. Start with the engine basics on why any motor runs hot..low coolant, thermostat, head gasket failure, water pump, ect..

 

Its not a powerstroke is it?

 

It is not a powerstroke. I'm looking for information from someone experienced with this particular engine...as in specific places to look. I guess I'm on my own. How is turbo boost controlled in these?

 

It would be best to get some sort of aftermarket temp gauge in the truck since the stock Ford gauges are notoriously inconsistent (aside from the obvious issue of not giving an actual numerical reading). That being said, unless your hauling heavy, I wouldn't expect a ton of fluctuation out of the gauge when you get up to temp. If the stuff you can see (i.e. radiator, water pump) is in good working order, perhaps it's a stuck thermostat. Or it could be someone threw in a non-OEM thermostat, many of which don't exactly have a sterling reputation when used in IDIs.

With that high of mileage, I'm wondering what sort of condition your injection pump and injectors are in, or what the timing is like by now. Do you know any of the history on the truck in terms of these parts? Not saying it's your problem definitively, but 'no power' complaints usually boil down to some combination of these things (assuming the low-end is still in good shape).

Mike

 

While I don't expect the gauge to be "accurate", I have been driving vehicles long enough to be able to tell when I open the hood if the temperature is reasonable or out of bounds. Under no load, 55 mph and less, temperature stays reasonable...and gauge stays centered.

I can understand injector pump not delivering fuel causing lack of power, but would that also cause overheating? Or does that sound more like a timing issue? Like I said, I'm new to diesels...how is injector timing handled/adjusted?

History of engine is not very well known. I have not yet had the opportunity to do much to it, as my own health has not been so good and all of my $'s have been going to my daughter's medical needs.

 

No, I wouldn't necessarily expect the IP to be causing issues with overheating, unless the timing is so off that the EGTs are getting out of hand.

Timing on these trucks is 'controlled' by the injection pump and the injectors. IP pulses fuel through the injector at a precise moment (much like a distributor distributes spark), so if the IP isn't strong enough to pop the injectors or if the injectors are worn out so that they pop when they're not supposed to, timing will be affected. You can adjust timing on the truck by rotating the IP (kinda like you'd adjust timing on a gasser by rotating the distributor). Only differences is that you DON"T adjust the IP while the truck is running like you would a distributor, and the timing equipment is a bit different (rarer, which means more expensive).

Mike

 

Not surprised by that answer. A would also be surprised if it were off. Could the turbo be having issues which might cause low power and overheating, perhaps a stuck waste gate? I haven't even had a chance to look closely at it yet.

 

basically, no. if the engine is overheating the problem is with either the water pump(i doubt it) the thermostat which i also do not think is the problem because it does not overheat as long as you stay under 55 mph, or the radiator being blocked. which is the most likely cause.
turbo issues would produce a lot of black smoke, and extremely high exhaust temperatures.
the first thing i would do is do a full test on the radiator for blocked tubes.
once you get the overheating issue solved, then we can move on to the low power issue.