I need some help.
My 92 w250 4x4 auto with 185000 miles on the inter cooled 5.9ctd has a loss of power.
The truck won't make any more power when pulling any hills at 45mph.
empty. When you give it more throttle it only works harder and gets hotter.
all fuel lines are ok, no fuel leaks at all, lift pump checks out, and a primitive test of the injectors proves all cylinders are contributing.
the injector pump is stock and probably original, as well as the injectors.
also i can hear the turbo whistle when i left off the throttle.
the trans is old but still works as it should.
any help help would be great.
thanks -cc

 

First, maybe fill out your signature so we have more details about your truck. Do you have a boost gauge and pryometer? Those can be helpful in diagnosing problems.

My first reaction to your problem is that you have a really sloppy (like all of us auto tranny drivers) torque converter. After a certain point, it doesn't get any more power to the ground and just makes a lot of heat, pouring all that heat into the cooling system. 185,000 miles really isn't that much. I have 260,000 on all original parts including injector pump, injectors, and transmission...and still going strong.

Second, have you noticed any more than usual black smoke out the back? If so, I would suspect a torn rubber boot on one of your induction/pressure couplers. Check the rubber couplers that attach your air plumbing from the turbo to the intercooler and from the intercooler to the intake manifold. It's also posible to have an air leak from the intercooler itself. Not enough air through the engine will really drive up exhaust temperatures and that will reflect in your cooling system eventually.

Also, a plugged fuel filter can be to blame for loss of power. But that shouldn't contribute to your overheating problem. If you have a REALLY clogged fuel filter you'll see white smoke out the back under heavy throttle, and you'll smell like you're pumping jet fuel out your tailpipe.

 

I'd also check the air filter and change it if it's been a while.

 

I agree, check your fuel filter, air filter. Make sure the intake to the turbo is free and clear of rags, and birds. And do a pressure test on the intercooler system.

 

Never mind, I don't want to hack in. I'll post on advice on pressure testing the intake system

 

All the filters are new(again) as of last sunday.
I'll check the whole intercooler system sunday.
no black smoke and no odd smells.
thanks all.
cc

 

when you say it gets hotter, are you refering to the coolant temp, or do you have a pyrometer in the exhaust?

 

I Was Actually Refering To The Coolant Temp Rising Considerably Compared To Exhaust Temps.

 

Sounds like the trans is dumping a lot of heat into the coolant.