CEL P0299 Turbocharger Underboost?????
08-19-2009, 07:34 PM
#1
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Thread Starter
Join Date: 04-03-2009
Location: atlanta, ga
Posts: 707
CEL P0299 Turbocharger Underboost?????
had this cel pop up just a few minutes ago...P0299 turbocharger underboost....driving in 5th gear at 59mph full throttle (which i rarely do in 5th) spooled to a max of 15 psi (have bsr) and when i let off the throttle the cel came up. not sure what the heck that means or what caused it
yesterday driving home i was shifting from 3rd to 4th and after the shift lost all boost.
not sure wtf happened but i would only spike to 3psi and it would get lower than that. by the way these things are Freakin slow with no boost...anyway...
thought i lost the turbo had to stop at walmart on the way home and when i came out boost was back and everything was ok. very very weird. no clue what happened here and i am not sure if the 2 problems are related or what.
anybody know anything about this or could shed some light on either or both of these????????????
yesterday driving home i was shifting from 3rd to 4th and after the shift lost all boost.
not sure wtf happened but i would only spike to 3psi and it would get lower than that. by the way these things are Freakin slow with no boost...anyway... thought i lost the turbo had to stop at walmart on the way home and when i came out boost was back and everything was ok. very very weird. no clue what happened here and i am not sure if the 2 problems are related or what.
anybody know anything about this or could shed some light on either or both of these????????????
08-19-2009, 09:01 PM
#2
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Join Date: 08-06-2009
Location: Crestview,FL
Posts: 181
Looks like P0299 applies to the wastegate.
#09-06-93-004: Intermittent MIL/Check Engine Light On, DTC P0299 or P0234 Set (Adjust Turbocharger Wastegate Actuator) - (Jul 21, 2009)
Subject: Intermittent MIL/Check Engine Light On, DTC P0299 or P0234 Set (Adjust Turbocharger Wastegate Actuator)
Models: 2008-2009 Chevrolet Cobalt, HHR
2008-2009 Pontiac Solstice GXP
2008-2009 Saturn SKY Redline
2008-2009 Opel GT
2008 Daewoo G2X
with Engine RPO LNF and LDK (Europe)
Please Refer to GMVIS
--------------------------------------------------------------------------------
Condition
Some customers may comment that the SES light is on. Upon inspection, you may find DTC P0299 (Turbocharger Engine Underboost) or P0234 (Turbocharger Engine Overboost) set.
Cause
This condition may be caused by a mis-adjusted wastegate.
Correction
Note: The wastegate adjustment is sometimes a very fine process. When adjusting the wastegate, only small adjustments should be made. Loosen one nut at a time and only adjust the nut one turn at a time; then tighten the other nut against the shaft and test drive to verify. This may have to be performed several times to achieve the desired boost level. To ensure proper adjustment, the vehicle should be at full operating temperature when testing. The vehicle will be very hot and may need to cool between adjustments. Too large of an adjustment can cause repeat DTCs.
Adjust the turbocharger wastegate. Refer to Turbocharger Wastegate Actuator Adjustment in SI.
Troubleshooting Tips for DTC P0299 - Turbocharger Engine Underboost
To increase boost, adjust the nuts (in) towards the actuator; in essence making the shaft shorter.
Troubleshooting Tips for DTC P0234 - Turbocharger Engine Overboost
To reduce boost, adjust the nuts (out) towards the end of the shaft; in essence making the shaft longer.
#09-06-93-004: Intermittent MIL/Check Engine Light On, DTC P0299 or P0234 Set (Adjust Turbocharger Wastegate Actuator) - (Jul 21, 2009)
Subject: Intermittent MIL/Check Engine Light On, DTC P0299 or P0234 Set (Adjust Turbocharger Wastegate Actuator)
Models: 2008-2009 Chevrolet Cobalt, HHR
2008-2009 Pontiac Solstice GXP
2008-2009 Saturn SKY Redline
2008-2009 Opel GT
2008 Daewoo G2X
with Engine RPO LNF and LDK (Europe)
Please Refer to GMVIS
--------------------------------------------------------------------------------
Condition
Some customers may comment that the SES light is on. Upon inspection, you may find DTC P0299 (Turbocharger Engine Underboost) or P0234 (Turbocharger Engine Overboost) set.
Cause
This condition may be caused by a mis-adjusted wastegate.
Correction
Note: The wastegate adjustment is sometimes a very fine process. When adjusting the wastegate, only small adjustments should be made. Loosen one nut at a time and only adjust the nut one turn at a time; then tighten the other nut against the shaft and test drive to verify. This may have to be performed several times to achieve the desired boost level. To ensure proper adjustment, the vehicle should be at full operating temperature when testing. The vehicle will be very hot and may need to cool between adjustments. Too large of an adjustment can cause repeat DTCs.
Adjust the turbocharger wastegate. Refer to Turbocharger Wastegate Actuator Adjustment in SI.
Troubleshooting Tips for DTC P0299 - Turbocharger Engine Underboost
To increase boost, adjust the nuts (in) towards the actuator; in essence making the shaft shorter.
Troubleshooting Tips for DTC P0234 - Turbocharger Engine Overboost
To reduce boost, adjust the nuts (out) towards the end of the shaft; in essence making the shaft longer.
08-19-2009, 09:05 PM
#3
Senior Member
Join Date: 08-06-2009
Location: Crestview,FL
Posts: 181
Or could be a broken/cracked nipple on the actuator. Didn't notice the loss of boost in your post so it could be this.
#PIP4520: Low Boost / Power And/Or DTC P0299 Or P0101 - keywords actuator boost CAC charge control cooler driveability DTC ECM engine gas lnf low maf MIL reduced reducedpwmde SES wastegate - (Nov 4, 2008)
Subject: Low Boost/Power and/or DTC P0299 or P0101
Models: 2008-2009 Chevrolet Cobalt SS Only
2008-2009 Chevrolet HHR SS Only
2007-2009 Pontiac Solstice GXP
2007-2009 Saturn Sky Redline
With Engine RPO LNF Only
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A technician may encounter a vehicle with a low boost/power condition and/or DTC P0299 and or P0101 setting. This may be the result of a cracked or broken fitting at the turbocharger assembly.
Recommendation/Instructions:
It has been determined that the nipple for the turbocharger wastegate actuator may be damaged causing this condition. If this concern is noted please inspect the area on the underside of the turbo compressor housing for the wastegate actuator solenoid valve. The nipple (see CALLOUT #1) may have been damaged causing a loss of boost pressure. It may be necessary to remove the charge air duct for a closer inspection. See eSI "Turbocharger Wastegate Actuator Replacement" for solenoid replacement procedure.
This solenoid is available separate from the turbocharger and should be replaced as a sub assembly. Do not replace the turbocharger assembly.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
#PIP4520: Low Boost / Power And/Or DTC P0299 Or P0101 - keywords actuator boost CAC charge control cooler driveability DTC ECM engine gas lnf low maf MIL reduced reducedpwmde SES wastegate - (Nov 4, 2008)
Subject: Low Boost/Power and/or DTC P0299 or P0101
Models: 2008-2009 Chevrolet Cobalt SS Only
2008-2009 Chevrolet HHR SS Only
2007-2009 Pontiac Solstice GXP
2007-2009 Saturn Sky Redline
With Engine RPO LNF Only
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A technician may encounter a vehicle with a low boost/power condition and/or DTC P0299 and or P0101 setting. This may be the result of a cracked or broken fitting at the turbocharger assembly.
Recommendation/Instructions:
It has been determined that the nipple for the turbocharger wastegate actuator may be damaged causing this condition. If this concern is noted please inspect the area on the underside of the turbo compressor housing for the wastegate actuator solenoid valve. The nipple (see CALLOUT #1) may have been damaged causing a loss of boost pressure. It may be necessary to remove the charge air duct for a closer inspection. See eSI "Turbocharger Wastegate Actuator Replacement" for solenoid replacement procedure.
This solenoid is available separate from the turbocharger and should be replaced as a sub assembly. Do not replace the turbocharger assembly.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
08-19-2009, 09:26 PM
#4
Senior Member
Thread Starter
Join Date: 04-03-2009
Location: atlanta, ga
Posts: 707
the broken nipple
sounds more like a possibility than the rod being out of adjustment since the problem was so sudden. after i lost boost and it "fixed" itself i still hit 20 psi so pressure has not gone gradually down if the rod came out of adjustment. anyway i will check out the wastegate tomorrow when it is light out. i'll clear the code and see if it repeats itself. also when i lost boost there was no cel which was wierd too.
we'll see..........
sounds more like a possibility than the rod being out of adjustment since the problem was so sudden. after i lost boost and it "fixed" itself i still hit 20 psi so pressure has not gone gradually down if the rod came out of adjustment. anyway i will check out the wastegate tomorrow when it is light out. i'll clear the code and see if it repeats itself. also when i lost boost there was no cel which was wierd too.we'll see..........
Or could be a broken/cracked nipple on the actuator. Didn't notice the loss of boost in your post so it could be this.
#PIP4520: Low Boost / Power And/Or DTC P0299 Or P0101 - keywords actuator boost CAC charge control cooler driveability DTC ECM engine gas lnf low maf MIL reduced reducedpwmde SES wastegate - (Nov 4, 2008)
Subject: Low Boost/Power and/or DTC P0299 or P0101
Models: 2008-2009 Chevrolet Cobalt SS Only
2008-2009 Chevrolet HHR SS Only
2007-2009 Pontiac Solstice GXP
2007-2009 Saturn Sky Redline
With Engine RPO LNF Only
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A technician may encounter a vehicle with a low boost/power condition and/or DTC P0299 and or P0101 setting. This may be the result of a cracked or broken fitting at the turbocharger assembly.
Recommendation/Instructions:
It has been determined that the nipple for the turbocharger wastegate actuator may be damaged causing this condition. If this concern is noted please inspect the area on the underside of the turbo compressor housing for the wastegate actuator solenoid valve. The nipple (see CALLOUT #1) may have been damaged causing a loss of boost pressure. It may be necessary to remove the charge air duct for a closer inspection. See eSI "Turbocharger Wastegate Actuator Replacement" for solenoid replacement procedure.
This solenoid is available separate from the turbocharger and should be replaced as a sub assembly. Do not replace the turbocharger assembly.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
#PIP4520: Low Boost / Power And/Or DTC P0299 Or P0101 - keywords actuator boost CAC charge control cooler driveability DTC ECM engine gas lnf low maf MIL reduced reducedpwmde SES wastegate - (Nov 4, 2008)
Subject: Low Boost/Power and/or DTC P0299 or P0101
Models: 2008-2009 Chevrolet Cobalt SS Only
2008-2009 Chevrolet HHR SS Only
2007-2009 Pontiac Solstice GXP
2007-2009 Saturn Sky Redline
With Engine RPO LNF Only
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A technician may encounter a vehicle with a low boost/power condition and/or DTC P0299 and or P0101 setting. This may be the result of a cracked or broken fitting at the turbocharger assembly.
Recommendation/Instructions:
It has been determined that the nipple for the turbocharger wastegate actuator may be damaged causing this condition. If this concern is noted please inspect the area on the underside of the turbo compressor housing for the wastegate actuator solenoid valve. The nipple (see CALLOUT #1) may have been damaged causing a loss of boost pressure. It may be necessary to remove the charge air duct for a closer inspection. See eSI "Turbocharger Wastegate Actuator Replacement" for solenoid replacement procedure.
This solenoid is available separate from the turbocharger and should be replaced as a sub assembly. Do not replace the turbocharger assembly.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
08-22-2009, 04:57 PM
#5
Senior Member
Thread Starter
Join Date: 04-03-2009
Location: atlanta, ga
Posts: 707
well today i lost boost again after a nls from 2nd to third.... did not throw a code and it didn't the 1st time either
at a redlight i cut the engine off and started it back up and i had boost again. leads me to believe its something in the tune. gonna take the bsr off for a couple of days and see what happens.
i checked all the piping...no leaks or cracks...checked bypass valve...wastegate looked fine but i didn't jack up the car and it's not real accessible from the engine bay but it looked ok...
did not throw a code and it didn't the 1st time eitherat a redlight i cut the engine off and started it back up and i had boost again. leads me to believe its something in the tune. gonna take the bsr off for a couple of days and see what happens.
i checked all the piping...no leaks or cracks...checked bypass valve...wastegate looked fine but i didn't jack up the car and it's not real accessible from the engine bay but it looked ok...
08-23-2009, 05:45 AM
#6
Senior Member
Join Date: 01-19-2008
Location: Delaware
Posts: 120
I just had this problem recently. After having my HHr for a month, and replacing the upper charge pipe a couple of times along with the entire turbo assembly. The problem turned out to be the lower pipe from the intercooler to the intake manifold. The plastic was flexing under boost where the sensor mounts to the pipe. The pressure pipes on these things are junk. Good luck.
08-23-2009, 11:42 AM
#7
Senior Member
Thread Starter
Join Date: 04-03-2009
Location: atlanta, ga
Posts: 707
thanks for the input bowtie...i'll check it out. whenever i lose boost i can shut the car off and when i turn it back on boost is back
I just had this problem recently. After having my HHr for a month, and replacing the upper charge pipe a couple of times along with the entire turbo assembly. The problem turned out to be the lower pipe from the intercooler to the intake manifold. The plastic was flexing under boost where the sensor mounts to the pipe. The pressure pipes on these things are junk. Good luck.
08-23-2009, 01:02 PM
#8
Senior Member
Join Date: 01-19-2008
Location: Delaware
Posts: 120
That's exactly what mine was doing. They originally said the problem was the turbo actuator but I believe it was the lower pipe all along. They had to replace the lower pipe a couple of times before it was corrected. When you see how the sensor is mounted, you will understand what I am talking about.
08-24-2009, 10:17 PM
#9
Member
Join Date: 12-20-2008
Location: Flint, MI
Posts: 85
this was exactly what was happening to me as well. athey replaced the solenoid valve and gave me a new turbo. It has been better but sometimes I wont boost past 12-15psi and other times I hit 20-24psi, but it hasn't totally cut out in a month or so.
08-25-2009, 05:30 PM
#10
Senior Member
Join Date: 01-19-2008
Location: Delaware
Posts: 120
Had to have mine towed to the dealer last night. Sitting in traffic and the temp gauge went to the top. Picked it up today. Turns out they didn't fully seat the plug for the cooling fan when they replaced the turbo and piping.