My truck just turned 100k and I have noticed that sometime my boost is really low. I will be at 15k fuel pressure and 2-3lbs of boost (under acceleration). This doesnt seem right at all. Other times it is around 8-10lbs like normal.

I recently flushed the coolant, replaced the water pump, thermostat, upper and lower radiator hoses. To get to the lower radiator hose I took the clamp off the turbo/cool side outlet that runs into the intercooler in order to get to the hose clamp. All the clamps seem tight.

I did notice that when I took the oil filter out that there was a very thick sticky black stuff on the inlet of the turbo. Is this normal? Is there maintenance that needs to be done on this turbo?

Thanks in advance

 

Any difference in engine sound or performance during the low boost ? My boost gauge was acting up and it was the boost sensor.

 

Lots of things to look at.

The "black stuff" in the inlet of the turbo is not normal. you may have lost the seal that allows oil to run out. There is no maintenance, only rebuild.

The intercooler boots from the factory are not know for being the best. Yours could have a leak.

This can also be electronic gremlins... MAP sensor getting finicky comes to mind.

 

My mileage is also down 3mpg. Truck has lost power. Turbo (when the boost is low) is almost non existent. When it goes back to normal then it i hear it just like i always do.

How do i test for leaks on the boots?

Is there a rebuild kit for these turbos? Any tutorials or hints?

 

Now I go back and notice that you have a 6.7... and you have a variable vane turbo.

Turbo rebuilding is not a DIY thingie. You have to give it to someone that knows what they are doing. That said, you could have sticky vanes. They get clogged with soot. and are either slow to function or get stuck open.

To test boots (or the system as a whole) get an appropriate sized PVC cap. Install a schrader valve in the cap so it doesn't leak. Install the cap on the boot right where the tube coming from the turbo goes. Clamp it in and pressurize system... look for leaks. Not just in the boots, but the CAC and the rest of the system too.

 

Yes I have a 6.7, Is there any way to clean the vanes?

 

Check the turbo for a cleaning port if there is one you can clean it. Usually if turbo vanes are sticking you will get a P2262 code. Cleaning can be done at a Dealership since a special tool is used, or you can buy the tools and do it yourself.
If turbo is not drilled for cleaning port you will need this tool.
http://www.shopfreedomracing.com/Tur...0143-10143.htm

Cleaning tool needed to clean turbo

http://www.handsontools.com/Miller-M...-_p_35134.html

turbo cleaning and drilling for cleaning port.

The price of tools would make me think maybe having a dealer perform cleaning since cleaning is not always 100% effective. Also you may need to replace turbo if cleaning doesn't work. 6.7L Turbo have come down in price, since they are all remans now. I have replaced my fair share of turbos and there are a few tricks on the 6.7 on replacing them or you can do it the hard way. I would also replace the crankcase breather filter if you are seeing oil in the crankcase breather hose to the turbo.

 

HOLY MOLY 900 bucks!!!

I just replaced the CCV filter. I will clean the MAP and tighten the intercooler piping since i moved it around. And then go from there.

 

I know very expensive tools, lucky for me the shop pays for all my diesel tools. To drill and tap plus clean turbo 2.5 hours that's alot cheaper then buying the tools. There is also a flash update to PCM that goes along with the cleaning. All replacement turbos come with the cleaning port. Good Luck

 

Cleaned the MAP - I see change, it drives better but no change in boost.

Tightened up the clamps on the turbo coolside outlet to intercooler inlet. - No change.

I dont have a cleaning port - Maybe its time for after market?

 

When you turn ignition off engine not running can you hear turbo actuator moving? If you do not hear actuator move then vanes are most likely stuck. Put exhaust brake into on position and drive, does exhaust brake work and slow vehicle down?