I have a 2005 LT. Even after truck is warm, engine is idling very rough. RPM's are fluctuating between 1 & 0. Couple times it dropped to 0 and stalled out. There's also major hesitation when accelerating. I took it to a local place and they did a throttle body cleaning and it helped, but only for about a week or so, then it came back. Some are saying to replace the throttle body, and that this is a common issue with this model. Any suggestions?
Oh yea, check-engine light is on, but it's not giving a code for throttle. It's giving a code for thermostat. But the guy at the shop said that's not causing my issue. Please help. Thx!

 

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> raili2000,

Since having the throttle body cleaned didn't seem to help, you may want to consider the EVAP purge solenoid. This is just a suggestion, not a diagnosis. Please have your vehicle inspected for an official diagnosis. Keep us posted.

Have a great day!

Louis
GM Customer Service

 

I'll mention that to whichever shop I take it to. I guess my logic was since the TB cleaning helped, if for a short time, it might have been on the right track. What does the EVAP solenoid do? Is it easily replaceable?

 

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> It may be a good idea to replace the throttle body. After the vehicle is diagnosed, your service person should be able to advise a more accurate resolution. We can post suggestions on the boards, but many times a physical inspection is required to get a true understanding of what is causing the problem.

The EVAP (Evaporative Emission Control System) prevents gasoline vapors from being released into the air from the fuel tank and fuel system. I'm sorry, but I am not a technician, therefore I cannot comment on how easily it can be replaced. I advise you to inquire with your service person.

I hope this information was helpful. Please keep me posted.

Please don't hesitate to contact me with any additional questions.

Have a great day!

Louis
GM Customer Service

 

Louis, seems the I6 Trailblazer has a problem with hesistation. My local dealership assisted with this problem by "giving" me a new engine head, catalysit coverter, throttle body, fan clutch and upstream O2 sensor...yet problem still exists.

Has GM thought about looking into this sestemic problem?

Thanks,

 

recondrill,

I will be sure to document the posts in this thread and forward it to the proper departments. Currently, I am not showing any known problems regarding rough idle, hesitation, stalling or reduced power on Trailblazers. That is not to say that you are not experiencing any of these issues. Troubleshooting can be a difficult task at times, especially when it is not a known issue.

Was your technician able to duplicate the problem?

If you would like, if you PM me your VIN number, I can research your specific vehicle to see if any additional information is available.

I look forward to your response.

Louis
GM Customer Service

 

Thanks for the info. I will keep you guys posted on the outcome.

 

turned out to be a bad coil on cylinder # 1. Replaced coil and she runs great now. Thx for input.

 

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> rali2000,

Great to hear! Thanks for keeping us posted.

Louis
GM Customer Service

 

If I bring the truck to a dealer for diagnostic can they tell if a coil pack is bad or if it's a throttle body