Weird problem with my 2007 Sprinter

[yzeevy]

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Hello,

First, the whole turbocharger was rebuilt and rechecked by MB shop.

The problem is that after driving 35-45 miles (it also depends on the outside temp) the engine looses power, especially up hill.

If the engine slows down to 1200 - 1800 rpm and I try to accelerate, the engine get blocked / chocked.

The maximum speed I can get is 55 mph.

The engine LED, P0299 which indicates an underboost turbo turns on and goes off later.

If I stop for a couple of hours everything turns to be OK.

Anyone has an idea where this is coming from ? !

Thanks

 

[NatersXJ6]

No specific MB experience here, but lots of general diesel:

Is it a variable vane turbo? It sounds like the variable vane plate (slightly different names in different brands) is sticking or worn. Or the solenoid that dumps the variable vane pressure is sticking. My 6.0 Ford used to do the same, but not as bad. I cleaned and lubed the canes in the turbo just about every 18 months on that truck.

What is the boost doing when this happens? Staying low I assume to throw the code?

You could try some stiction eliminator in the oil, low cost to try but unlikely to really work.

I probably wouldn’t trust an MB shop to rebuild a turbo, better done yourself or at a diesel specialist, but I tend to be the untrusting sort.

 

[MontySquareo]

The variable vane turbo on those sprinters also have a electric servo motor to control the boost, and that could be failing but I would think it would throw a turbo/vnt actuator code.

I would ask your questions here https://sprinter-source.com/forums/index.php