Turbo problem

[dfayette]

06 F250 6.0 - just threw a P0299 code - turbo underboost. Anyone know if this is leading to something serious?
I cleared the code and it seems to run OK.
Turbo was repaired couple months ago - replaced the innards - after something cracked and it made a lot of smoke. Oil leaking caused the smoke.

[HAM_RADIO_MAN]

It might be time to clean the turbo or start looking for a leak.


Q: How do I know if my turbo is bad.

A: A turbocharger is a very simple device basically 2 windmills on one shaft. A lot of “ bad turbo’s” on 6.0’s are simply dirty and can be restored to proper working order in about 4 hours and a little elbow grease. The exception is if the bearings are bad or if it has more than about .004 in of end play or if you can move the shaft side to side enough to cause it to rub the housing. If you can spin it by hand and it seams to move freely then there is a good chance it’s fine. Most turbo problems are bad bearings , cracks in pressurized components like hoses, boots , intercooler , or excess carbon and soot.
From time to time a VGT solenoid will fail ,but this is pretty rare. One more thing is to inspect for damaged compressor blades. The major cause fo this is aftermarket air intakes. The best thing you can do to keep your turbo happy for a long time is keep it cool and lubed and clean. This means stick with the OEM air filter unless you need to make more than 500HP.



Q: Turbo charger spools up slowly

A: VGT solenoid bad or unplugged, Low boost due to leaking CAC boots or tubes, Exhaust Leak to turbo turbo vanes are coked up with rust and carbon.


Q: Turbo charger builds to much boost

A: vanes are coked up with rust and carbon, hot tune , stuck or faulty VGT solenoid.



Q: Low Boost levels

A: VGT solenoid bad or unplugged, Low boost due to leaking CAC boots or tubes, CAC tank cracked Exhaust Leak to turbo turbo vanes are coked up with rust and carbon.



Q: I heard a loud pop / bang and now I can't make boost or power and my truck blows black smoke , Did I blow up my engine??

A: No Worries, Due to a recent repair or oil contamination your CAC boot has blown off under load. Clean the tubes and boots with brake cleaner then spray with hair spray or spray adhesive then reassemble. The best way to prevent this and to keep your boots from rotting out is to reroute the crank case vent.


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[dfayette]

Thanks for the reply.
What's a CAC boot?
And how would I check for leaks?
And the VGT solenoid? Where would I find it?

I know gas motors but haven't yet dove into the diesel yet since it's been under warranty. Think it's time.- since I'm retired and all.

[HAM_RADIO_MAN]

CAC boot= the rubber ose looking thing that connects the high pressure side of the turbo together. cac= Charge Air Cooler. Remove and inspect them for leaks. VGT solenoid is on the very top of the turbo.

Read this link for a good explanation. Powerstroke 6.0L Technical Intro Manual

[dfayette]

Thanks, sounds like I get to learn something.

When the problem started I was just leaving a parking lot. No noise, no nothing, just no boost. Truck ran and got up to speed, just not quickly, and with lots of black smoke. With WOT it sounded like it was drowning and there was lots of smoke. Also after each shift it make a strange sound like it was choking, kind of hard to describe but it sounded like an air brake and it did it several times. Like a valve was opening and closing.

After I stopped the truck then restarted it seemed to be OK, although it will only get up to 20 lbs boost and it spools up slowly.

[HAM_RADIO_MAN]

You can also check the hose to the map sensor.( left side ) The tube that feeds the Exhaust back pressure sensor can also clog and cause some weird stuff to happen. That is located on the right side of the engine toward the front. See the last link in my signature for great pdf's and photos to show you were everything is.

[PSDMikeB]

Mine was behaving similarly... one minute it would bog down and wouldn't even budge, then after you got it rolling along, everything would seem normal. Tons of black smoke when trying to take off from a stop. Did not sound like I had a boost or exhaust leak.

I came to the conclusion it was either the turbo being coked up, or else the EGR valve sticking open. The simplest is to clean the EGR valve. When you decide to do it, park the truck nose down overhight so that you can look for signs of a blown EGR cooler. Since you have already had the turbo worked on, I would suspect that is not your problem, but you never know. Try cleaning the EGR valve first, then you may be looking at cleaning the turbo. Other places to look are the various sensors (MAP, EBP, etc) and boots as Ham Radio said.

MikeB

[justa03]

I also would be looking at the EGR valve sticking. Another dumb thing I have seen is the CAT just starting to plug up and cause an issue like this and after so long it would just not make power anytime at all and just smoke. Just a thought