We drove the coach from Augusta to Charleston for a weekend with the local Good Sam's Club today.

I had NO boost pressure for the whole trip. All engine Temperatures and Pressures were normal for the trip and never varied during the trip. The Boost gauge never moved off the "0" peg. I might have thought a gauge problem, but the engine power was down substantially and would not hold speed even on the small rolling hills on I-20. Also black smoke when the engine was trying to accelerate.

Have done no troubleshooting yet. Tomorrow I will try to check clamps, pipes, after cooler, etc. Checked prices on a rebuilt Turbo online tonight. Looks like about $1K. Might get away with less than a "Cagle".

Nick

First thing to check is the air filter. It can have a substantial impact on boost. However, your symptoms do point to a bad turbo - except that only bearing failure, which would stall the turbo, is rare.

Good luck...

http://jmturbo.com
Replacement turbos

Before you change the turbo check the two "flexible" stainless elbows that connect the exhaust manifolds to the turbo inlet. The tip off is lots of black soot around the back of the engine and on the walls of the engine bay. On mine, (and confirmed by Cat) these break after a few years due to the high heat and flexing as the engine operates. Its a messy job but not overly difficult because you can access them from under the bed. The heat blankets may be cooked and those are available from the manufacturer in California (their nameplate is on each blanket). Once replaced, the boost will return and indicate up to about 10 psi under load. Black smoke on acceleration is normal and not an indication of a bad turbo. You do not need to remove the turbo to change these elbows.

NICK when our turbo (pipe rusted thru)you could not see it when stopped. the turbo is bolted on solid and the pipe after the turbo is also bolted tight.When you look it the pipe looks solid.put some tran. fluid in the first fuel filter it will smoke at the crack. get the part that goes from the rear of the turbo to the exhaust pipe(turbo outlet is smaller than the exhaust pipe.if you see any black on the carpet of the motor cover that could be your problem.Hope you find the problem is not the turbo (they cost $1100,00).
lenny
PS> still hoping to see you and Donna in JULY

Finally got around to troubleshooting the turbo problem. Here is the turbo mounted on the back of the engine



This is what I found right away. The pipe with the hole in is from the after cooler to the intake manifold.



The damage was done by rubbing against the larger pipe from the air filter to the turbo inlet.

Had the hole patched.



Reinstalled the pipes and you can see how they would rub together.



Cut an old rubber connector and intalled it on the upper pipe.



Now the bottom line. Still no boost pressure.
Now I do think it's a gauge problem also. Will trouble shoot the gauge as soon as I can find the connection at the engine. It is a direct reading gauge so should have a small rubber line attached going to the cockpit gauge.

Were you able to road test? You can't get much volume of heat and gas through the impeller unless you can load the engine.

quote:

Originally posted by Rusty:
Were you able to road test? You can't get much volume of heat and gas through the impeller unless you can load the engine.

Drove it to Thomson exit on I-20. About 25 miles round trip. Couple small rolling hills. Engine ran fine and this time pulled the hills with no loss of speed on the hills.

Nick

I agree, then, the tubing to the boost gage has become detached.

Turned out to be a bad gauge. Replaced it with a matching VDO unit from Summitt Racing and all is well in the world again. Guess it was lucky that I found the hole in the pipe because of a bad guage.

Nick

Kewl! Now to just figure out where to fit 8 people for the trip to LA...

Wow, that's great news Nick.
Jim

the line on the8.3 Cummins broke at the turbo.It was getting into the sleeping area .you could tell by the soot.just can't look at it they are mounted very solid mine were cracked thru.WE needed the coupler to the exhaust .even ran good with no loss of power .If you see soot around the back of your engine cover inside and out side you could have a broken pipe not even know it .
good luck
we hope to see you end of july if that is ok/.
get you exact date later if I improve enough to drive blew my quad again.