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No boost, louder exhaust...
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=83200		 Page 1 of 1
Author:  Billy M [ Mon Oct 05, 2015 1:50 pm ]
Post subject:  No boost, louder exhaust...
I figured I would start a thread on this, since I couldn't find an existing one with these symptoms. I'll have more details this evening once I look at it in depth, but here are my current symptoms.

1.) No boost. I have no cat and a Magnaflow-ish aftermarket muffler. I can always here the turbo spooling. I now hear no spooling.
2.) Low power. She runs fine, idles smooth, goes through the gears just fine. Basically runs like a N/A diesel.
3.) Louder exhaust. The exhaust is a little deeper/throatier/louder coming out of the back. Not like an exhaust leak, just louder & different.
4.) I did get a CEL when this started. I'll scan it tonight & post my results.

Side note...I did keep my eye on my oil pressure light and looked for smoke, just in case the turbo crapped out and was puking oil. Everything was fine. I'll be checking vacuum hoses, turbo play/spin, and all other obvious signs. I do check my turbo every other oil change. I checked it 6,000 miles ago. I did a brief check and all boost hoses were fine. Nothing obvious jumped out at me. I have a spare turbo sitting on the shelf...just in case. My turbo was replaced by the previous owner at 80,000 miles by the stealership. The replacement turbo has almost 65K miles on it.

Billy
Author:  mass-hole [ Mon Oct 05, 2015 2:40 pm ]
Post subject:  Re: No boost, louder exhaust...
Billy M wrote:
I figured I would start a thread on this, since I couldn't find an existing one with these symptoms. I'll have more details this evening once I look at it in depth, but here are my current symptoms.

1.) No boost. I have no cat and a Magnaflow-ish aftermarket muffler. I can always here the turbo spooling. I now hear no spooling.
2.) Low power. She runs fine, idles smooth, goes through the gears just fine. Basically runs like a N/A diesel.
3.) Louder exhaust. The exhaust is a little deeper/throatier/louder coming out of the back. Not like an exhaust leak, just louder & different.
4.) I did get a CEL when this started. I'll scan it tonight & post my results.

Side note...I did keep my eye on my oil pressure light and looked for smoke, just in case the turbo crapped out and was puking oil. Everything was fine. I'll be checking vacuum hoses, turbo play/spin, and all other obvious signs. I do check my turbo every other oil change. I checked it 6,000 miles ago. I did a brief check and all boost hoses were fine. Nothing obvious jumped out at me. I have a spare turbo sitting on the shelf...just in case. My turbo was replaced by the previous owner at 80,000 miles by the stealership. The replacement turbo has almost 65K miles on it.

Billy


Did a CAC hose disconnect? That sounds like what happened to my wife the other day, the passenger side CAC hose popped off the turbo outlet.

EDIT: NVM, I thought you said you COULD hear spooling. Guess its not the CAC hose.
Author:  Billy M [ Mon Oct 05, 2015 2:58 pm ]
Post subject:  Re: No boost, louder exhaust...
mass-hole wrote:
Did a CAC hose disconnect? That sounds like what happened to my wife the other day, the passenger side CAC hose popped off the turbo outlet.

EDIT: NVM, I thought you said you COULD hear spooling. Guess its not the CAC hose.


Thanks. I did check the CAC hoses and I have had a hose remove itself before. The Jeep will go into limp mode when that happens. You get a lot of moving air sounds under the hood as well. I have no limp mode, just boost-less running. I'm actually surprised it didn't go into limp mode from a low boost condition.?? Maybe it's spooling very little. Just not enough to hear.?? Hopefully, I'll figure it out this evening.
Author:  flash7210 [ Mon Oct 05, 2015 3:31 pm ]
Post subject:  Re: No boost, louder exhaust...
it could be that the exhaust sound is not related to the lack of turbo boost.
So check all the vacuum lines going to the turbo.
At idle, vacuum at the turbo port sbould be high.

High vacuum = more boost
Low vacuum = less boost
Author:  Billy M [ Mon Oct 05, 2015 3:46 pm ]
Post subject:  Re: No boost, louder exhaust...
flash7210 wrote:
it could be that the exhaust sound is not related to the lack of turbo boost.
So check all the vacuum lines going to the turbo.
At idle, vacuum at the turbo port sbould be high.

High vacuum = more boost
Low vacuum = less boost


I agree. Although, I won't complain if it sounds like this from now on. It sounds throatier. I like it better! :D

Good info. I was going to check the vacuum line anyway. I'll pull it off and check the vacuum on it as well. Vacuum lines can collapse when they get old and cause all sorts of headaches. I actually just dealt with a collapsed vacuum line on my mother's car.

Thanks.
Author:  JD3020 [ Mon Oct 05, 2015 7:17 pm ]
Post subject:  Re: No boost, louder exhaust...
If it has a louder/deeper tone and no power, then its possible that the vanes in the turbo are stuck fully open. Pretty common issue with the VGT's in the 6.0 Powerstrokes, vanes get rusty or gunked up with soot and stick open causing a lot of problems.
Author:  Billy M [ Mon Oct 05, 2015 8:30 pm ]
Post subject:  Re: No boost, louder exhaust...
So...here's what I was able to check tonight.

*Turbo spins freely with normal tolerances.
*It had two codes. Both P0299. Turbo underboost condition. I knew that.
*All vacuum hoses looked fine. I blew through the hose going to the actuator and it didn't appear to be leaking or obstructed.
*I started it and pulled the vac hose off at the turbo. It had plenty of vacuum.

I drove it around the block. Same condition. CEL didn't come back on, but I'm sure it will. I only got up to about 25 MPH.

JD3020...that sounds like a good possibility. Has anyone here ever had that happen? What do the Powerstroke guys do to fix that? I did the EHM to an oil catch can when I got it at 102K miles. I was wondering if the turbo needed the oily moisture to keep the vanes lubed/moving. Could that be the culprit?

Thanks for the help.
Author:  flash7210 [ Mon Oct 05, 2015 8:57 pm ]
Post subject:  Re: No boost, louder exhaust...
For your next test you will need to carefully look down at your turbo. Below the vacuum actuator is a rod that moves the vanes inside the turbo.
With the engine idling, pull off the vacuum line.
You should see the rod drop down.
Reconnect the vacuum line and you should see the rod pull up.

If the rod does not move at all, the vanes inside the turbo are stuck.
Author:  Billy M [ Mon Oct 05, 2015 9:08 pm ]
Post subject:  Re: No boost, louder exhaust...
Thanks flash. I'll try that. Results will be posted.

OK. I located the rod. It was a little tough to see. You do have to get a good angle on it. I moved it with my finger to verify that it was the rod (probably broke it free). Started her up, took the hose off/on a few times. Rod moved up & down. Took it for a spin around the block. Bingo! Boost is back! Turbo response does seem a little sluggish though. It also still seems to be a little louder, so I think the turbo definitely needs cleaned out. Is there a procedure to clean this up/out?
Author:  flash7210 [ Mon Oct 05, 2015 10:12 pm ]
Post subject:  Re: No boost, louder exhaust...
Search here or on the VW TDI forums.
There is a turbo cleaning procedure that involves oven cleaner.
I have never tried it.

Its also possible that one of the vacuum solenoids is going bad.
Usually the fat solenoid, with the little filter hanging out the bottom of it, will start making a loud buzz when its going bad. And its a good idea to change that little filter.
Author:  Billy M [ Mon Oct 05, 2015 10:46 pm ]
Post subject:  Re: No boost, louder exhaust...
flash7210 wrote:
Search here or on the VW TDI forums.
There is a turbo cleaning procedure that involves oven cleaner.
I have never tried it.

Its also possible that one of the vacuum solenoids is going bad.
Usually the fat solenoid, with the little filter hanging out the bottom of it, will start making a loud buzz when its going bad. And its a good idea to change that little filter.


I've been doing some research and saw that. I'm not too crazy about flushing that crap through my engine. I'll double check the solenoid and probably remove the turbo to disassemble for a thorough cleaning. I wonder If the original turbo was replaced for the same reason?

Thanks for the input. I'm glad it wasn't something major.
Author:  Yeti [ Wed Oct 07, 2015 4:11 am ]
Post subject:  Re: No boost, louder exhaust...
for clean the vane you must dismount your turbo
Author:  geordi [ Wed Oct 07, 2015 5:37 pm ]
Post subject:  Re: No boost, louder exhaust...
You theoretically could clean the turbo without dismounting it or flushing anything through the system - the cleaner all needs to be on the exhaust side anyway. Drop the exhaust line from the back of the turbo and use a tube to spray the cleaner all around inside the turbo housing from the back (yes this will be difficult) and then close it back up again - now try starting it and give it a couple good revs. Chances are, your driveway will now have a black blast mark on it, messy! Hopefully that cures it for you, but hammering on the throttle can also clean things out. It's called an Italian Tune Up.
Author:  Billy M [ Thu Oct 08, 2015 10:58 am ]
Post subject:  Re: No boost, louder exhaust...
geordi wrote:
You theoretically could clean the turbo without dismounting it or flushing anything through the system - the cleaner all needs to be on the exhaust side anyway. Drop the exhaust line from the back of the turbo and use a tube to spray the cleaner all around inside the turbo housing from the back (yes this will be difficult) and then close it back up again - now try starting it and give it a couple good revs. Chances are, your driveway will now have a black blast mark on it, messy! Hopefully that cures it for you, but hammering on the throttle can also clean things out. It's called an Italian Tune Up.


Thanks geordi. I did see that procedure and I was going to check out the feasibility of doing that. I saw some people use foaming oven cleaner, then clean that out with brake or carb cleaner. I don't know if I'll use oven cleaner as that stuff is pretty potent. I'm not too crazy about that dripping on me or anything around me. That stuff will eat paint. I was hoping someone has done this procedure before on the CRD and would chime in on how it went, what chemicals they used, etc.

She gets the hammer down a handful of times a week getting on the highway. The turbo shouldn't be sooty from lack of "Italian tune-ups". =)
Author:  Yeti [ Fri Oct 09, 2015 5:19 pm ]
Post subject:  Re: No boost, louder exhaust...
in this mode you can clean the exaust vane , but the real problem when the vane are stuck is the actuator and the internal organs that act the vane , if the actuator go up and down when you unplug the vacuum hose the vane are not stuck
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