Engine/Transmission (1994 - 1998) No power low boost lotsa smoke. TURBO bad?

[BHaden]

Truck is in sig. I'm in springfield Mo. on a one day layover. I'm hauling RVs . Just dropped one in Ok City and heading back to Indiana. The last few days truck has developed a major problem. Engine has 327,000. As far as I know injectors and turbo are original. I'm running the HX-35 with the wastegate disconnected for more pressure on uphill pulls. It will do 30psi if I hold it but that is rare, usually no more than 28 or so and not often. If I put the pedal down hard and let off quick like across an intersection it will bark (no surprise) but I haven't done that maybe a handful of times. Now it is only capable of about half maximum boost. VERY slow spool off the line and a lot of black smoke. Tailpipe is REALLY black and sooted now. No power to speak of throught the rev range. Very sluggish and when it gets to 4th gear and the TC locks it simply dies. If I hold it down fairly hard it will eventually build to 12-13 lbs but all of this is acconpanied by much hotter EGT. I used to have to push to hit 1150, now it will get to 1400+ on even a slight grade and even runs over 1000 running empty and on level ground. I jusy replaced the fuel filter, cleaned the air filter, and checked the compressor blades which seem to look OK. All this, to me, says the turbo is dead. Could a turbo bark damage the exh turbine? Damage the wastegate, causing it to stick open ( it seems to have springload in the closed position )? Maybe it just wore out? Any comments would be helpful. TIA.

 

[HBarlow]

How about turbo spin and end play? Does it spin free and without noise with your fingers when the engine is off? Does it seem to have normal end play?

You might get lucky and have a bad sensor. I don't know anything about 12 valves but assume it has one or more sensors like 24 valve and HPCR engines.

 

[GOlsen]

Check your intercooler boots and make sure one of them hasn't torn or blown off.

 

[GAmes]

Yes, turbo bark can damage the turbo blades. In gas turbine engines a compressor stall requires some serious inspection. In your case I'd go to the simple things first. The boots sometimes come off, and if you haven't been under there to bend the inner fender lining away they rub and holes appear. A little side to side play is acceptable as long as the blades don't rub the housing. In and out is a no-go. FWIW, my original turbo lasted over 750k, but I never messed with the waste gate. I can easily push 32 pounds of boost, but rarely go over 20.

 

[AMink]

Start cheap and make sure your intercooler hoses are worn through or leaking.

 

[BHaden]

Start cheap and make sure your intercooler hoses are worn through or leaking.

OK you win the prize! I had looked and felt all the hoses and connections several times before and during this post. I was CONVINCED they were all OK.

Last night I put my right foot down hard to see what it would do and heard an obvious massive air leak. I pulled the entire pipe off the right side and found the hose right at the turbo elbow was on a little crooked which allowed it, over time, to slip out a little, about 1 inch radially. When not under boost it sat flush with the clamp and felt normal. Under pressure it raised up and leaked. I didn't even see it immediately even when I had the pipe in my hand.

Now I don't HAVE to do the turbo. Oo. Maybe I will anyway. It IS tired. .

 

[GAmes]

Darn it!! I thought I had won the prize. :-laf:-laf