smoking at low end & P0299

ohioredneck · **Joined:** Sat Apr 22, 2017 4:32 pm **Posts:** 6

I have a 2005 Jeep Liberty CRD with a GDE eco tune. Today, I was driving and when I took off, I noticed lack of power on the low end and started smoking pretty heavy on the low end and immediately got a P0299 code. Sounded like there was a pop can type of pop when it all happened. It still has power just roals coal on the low end until boost is fully up to par. Once boost is up to full operation, very little smoke if any and has normal power. Other thing I've noticed is that is started to sound growly on the engine exhaust. I've pulled the CAC hoses and inspected them, no leaks and no leaks with the intercooler. I'm wondering if the pop I heard was the VNT vanes got stuck on the high end instead of being variable...I cleaned the MAP sensor, which was pretty clean to start on top of that. I'm at a loss except thinking it is something with the turbo, wastegate, or vane actuation.

Anyone have any thoughts to this?

joe_ · **Posted:** Sat Apr 22, 2017 8:54 pm

From your description it sounds like a CAC hose popped off or burst, but you sound pretty confident that they're fine. I wonder if your EGR valve failed mechanically and you're leaking boost out into the exhaust.

You can check the VNT system, but I don't think they fail suddenly with a 'pop' sort of noise. There's a rod going from the vacuum actuator above the turbo down to the turbo. If you disconnect the vacuum line from the actuator, you should see the rod drop about 1/4". If not, the vanes may be stuck or the vacuum solenoid may have failed. Edit: Forgot to mention, that test should be done with the engine idling; might not be any vacuum in the system if the engine's shut off.

ohioredneck · **Joined:** Sat Apr 22, 2017 4:32 pm **Posts:** 6

Thank you for the input. I'll check it out this week and report back what I've found. Also to note, that the turbo doesn't sound like it spools down after I shut it off and has a different tune to the turbo whistle at the very low end and sounds normal at wide open throttle.

GordnadoCRD · **Posted:** Sat Apr 22, 2017 9:58 pm

The combination of things is definitely a headscratcher.

You mention a GDE tune but not a weeks kit.

It still doesn't make complete sense to me, but it might be worth taking a look at the rear of the exhaust manifold, where the pipe joins up to go behind the engine to the EGR.

If it popped loose, it would definitely change the exhaust sound, the turbo sound, and effect power. It's just when I picture it in my head I can't figure out how it still makes top end power, but loses so much down low. Maybe because it would be a (relatively) low volume leak, and the diesel outflows it at higher revs?

WWDiesel · **Posted:** Sat Apr 22, 2017 10:31 pm

Definitely sounds like you are loosing boost somewhere, cracked hose etc., or turbo is not performing as it should! :roll:

Very strange that it seems to be ok at higher rpm's!
The POP you heard, leads me to believe you blew a hose; check them real good!

:SOMBRERO:

ohioredneck · **Joined:** Sat Apr 22, 2017 4:32 pm **Posts:** 6

And the pop was just at acceleration before I started really any boost. But it wasn't a loud pop, just like if you open a can of soda type of pop. I've definitely checked the hoses and intercooler.

WWDiesel · **Posted:** Sat Apr 22, 2017 11:28 pm

ohioredneck wrote:

And the pop was just at acceleration before I started really any boost. But it wasn't a loud pop, just like if you open a can of soda type of pop. I've definitely checked the hoses and intercooler.

P0299 is underboost code, so computer is telling you there is a boost issue! :roll:

ohioredneck · **Joined:** Sat Apr 22, 2017 4:32 pm **Posts:** 6

Problem isolated! The vacuum orifice assembly near the passenger side of the fender-well is the root cause. I unplugged the vacuum line from where it feeds the the turbo vane actuator and there was no vacuum at all on idle, keeping the turbo vane actuator optimized for the high end boost instead of any low end performance...I then unplugged the main vacuum going into the entire assemble and kept popping it on and off and low and behold it started to work, so I'm thinking the diaphragm got stuck. I oscillated it a few times taking the hose on and off and was intermittent until it then started to be consistent. Just to be on the safe side, I might just order a new assembly to not repeat this scenario in case the diaphragm is going bad or look at the MAP sensor in case it is being inconsistent with it's readings

WWDiesel · **Posted:** Sun Apr 23, 2017 12:55 pm

ohioredneck wrote:

Problem isolated! The vacuum orifice assembly near the passenger side of the fender-well is the root cause. I unplugged the vacuum line from where it feeds the the turbo vane actuator and there was no vacuum at all on idle, keeping the turbo vane actuator optimized for the high end boost instead of any low end performance...I then unplugged the main vacuum going into the entire assemble and kept popping it on and off and low and behold it started to work, so I'm thinking the diaphragm got stuck. I oscillated it a few times taking the hose on and off and was intermittent until it then started to be consistent. Just to be on the safe side, I might just order a new assembly to not repeat this scenario in case the diaphragm is going bad or look at the MAP sensor in case it is being inconsistent with it's readings

These are the OEM part numbers in case you decide to order new ones:
Turbocharger Vacuum Modulator - 52109543AA ---- > http://www.factorychryslerparts.com/pro ... 52109543AA
Vacuum Solenoid - 4606226AC -----> http://www.factorychryslerparts.com/pro ... =4606226AC

Either part could cause vacuum issues! :wink:

Google the part numbers, you may can find them cheaper... :google:

Dennis MacGyver · **Posted:** Sun Jun 25, 2017 6:55 pm

Problem resolved.
Did a search here on Turbo & Vacuum.
Read some threads about the vacuum modulator and solenoid and did some analysis try to find vacuum further downstream of each fitting and device. Tested the electrical connections & made sure the wiring was intact. So at the last point where the vacuum leaves the modulator there was vacuum but not at the top of the device that sits atop of the turbo. So I pulled off the entire line from the modulator to the top of the turbo device and discovered a hole in the metal part of the line. The metal line had been rubbing against the heat shield around the top of the device on top of the turbo causing a total loss of vacuum at the turbo.

WWDiesel · **Posted:** Sun Jun 25, 2017 8:07 pm

Dennis MacGyver wrote:

Problem resolved.
Did a search here on Turbo & Vacuum.
Read some threads about the vacuum modulator and solenoid and did some analysis try to find vacuum further downstream of each fitting and device. Thested e the electrical connections & made sure the wiring was intact. So at the last point where the vacuum leaves the modulator there was vacuum but not at the top of the device that sits atop of the turbo. So I pulled off the entire line from the modulator to the top of the turbo device and discovered a hole in the metal part of the line. The metal line had been rubbing against the heat shield around the top of the device on top of the turbo causing a total loss of vacuum at the turbo.

Good deal! Glade you got it figured out and it was something simple!!! :BANANA:

smoking at low end & P0299

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