Mysterious Smoke At Cold Start Up!? - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 Vortec 5.3L V8 Engine and Drivetrain > OEM Issues

OEM Issues Original Equipment Repairs and/or Problems

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools
  #1  
Old 01-29-2011, 08:56 AM
AngryItalian AngryItalian is offline
Junior Member
 
2007 GMC Envoy Denali
Liquid Silver Metallic 5.3L V8 2WD
Join Date: Jan 2011
Location: Macon, GA
Posts: 2
Mysterious Smoke At Cold Start Up!?

Hello all,

Glad to be finally registered and set up! We bought a beautiful '07 Denali a few months back, and we absolutely love the truck. Not too long ago, I began noticing a fair amount of a blue-ish gray smoke coming from the tailpipe at cold startups. The frustrating thing was it was only an intermittent thing. It was kind of line a vintage airplane that when started, would puff out a large cloud of smoke and then that was it, nothing else. I also noticed the oil level was way below the lower x on the dipstick. The engine has been running fine, no noises, no CEL, etc. I did some early research here, and it seems others have had similar issues with the 5.3 liter. It was almost due for an oil change, so I took it into the dealer to have them check it out.

Their diagnosis was a faulty PCV valve, which they replaced under the 12 mo. Certified B2B warranty. They also recommended (and I took the bait hook line & sinker) to have a throttle body injection cleaning service and some upper engine induction chemical cleaning service done while they were in there. Total bill w/ the oil change was about $240 and all is now well. I will be keeping a very close eye to see if the smoke issue comes back, as well as the oil consumption level going forward. I can get past the oil consumption if that is truly "normal" for this type of engine, but a modern well maintained engine with 60k miles should not be spewing more smoke than the local bingo hall on a Friday night!

Any thoughts or feedback? I am hoping the PCV valve was truly the culprit! Thanks for any comments or help. AI
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 03-06-2011, 08:59 PM
Brian P's Avatar
Brian P Brian P is offline
Junior Member
 
2008 Chevy TrailBlazer LT
Graystone Metallic 5.3L V8 4X4
Join Date: Jul 2009
Location: Long Island, NY
Posts: 59
I caught mine doing this once in a rare while. It would just puff for a second after a cold start. It seems more likely that maybe one valve seal is leaking oil when the engine is stopped in a certain position (IE: the seal leaks when its valve is held open). The 4.8L on my father's truck will occasionally do this as well.

Have you noticed any smoke since the PCV change? At least with my experience I can't imagine it being the PCV since the smoke puff occurs instantly upon startup, as if the oil is already in the combustion chamber. I'll make a note to check my PCV anyway and replace it when I perform the tuneup.
__________________

2008 Chevy Trailblazer LT 5.3
1995 Olds Cutlass Supreme SL coupe 3400 V6
Reply With Quote Quick reply to this message
  #3  
Old 03-06-2011, 10:14 PM
bromanjr's Avatar
bromanjr bromanjr is offline
Senior Member
 
2004 GMC Envoy SLT XUV
Indigo Blue Metallic 5.3L V8 2WD
Join Date: Sep 2010
Location: Howell, MI
Posts: 691
I had a related issue with my 5.3 after I purchased it, mostly the oil consumption problem. I never noticed any start-up smoke (but never looked for it either).

When I purchased the truck it had 164,000 miles and an unknown service history. It used oil excessively, about 1 qt/1000 miles with no apparent leaks. After a couple oil changes and many added quarts between changes, I searched for an explanation.

I found that in the TrailVoys, the 5.3, which is an Aluminum block, seemed to have a much worse than normal oil usage history. It seemed the iron block versions in the Pickups/Suburbans/Avalanches were not reporting the same level of the problem. Not sure that the aluminum block was the issue, I kept searching. I found that the PCV chamber inside the Driver side valve cover was faulted for sludging up easily and GM was replacing the Valve cover as a fix for the problem, a TSB (don't remember the number) is what I found.

I found and purchased a new GM valve cover w/new PCV for the drivers side. Put it on and have been seeing vastly decreased oil usage for the last 6,000 miles. Also, on top of this I have been driving aggressively (my normal routine) and as time goes by, it has also been idling and running smoother. I attribute the aggressive driving is helping clean the combustion chambers and rings. So after two 3,500 mile trips and needed maintenance my oil usage is down significantly. Last oil change at 4,000 miles and oil was barely low.

I am hoping for continued normal oil consumption. I thought about just replacing the PCV valve and agree it should help. I chose to replace the valve cover because my engine was extremely sludged (remember, unknown maintenance history) and according to the TSB the cover could not be effectively cleaned plus the PCV chamber had a probable seal failure that was mentioned in the TSB.

My
__________________
182,000 and counting. Superchips 2914 Tune, NAV upgrade.
Reply With Quote Quick reply to this message
  #4  
Old 03-07-2011, 07:30 PM
AngryItalian AngryItalian is offline
Junior Member
 
2007 GMC Envoy Denali
Liquid Silver Metallic 5.3L V8 2WD
Join Date: Jan 2011
Location: Macon, GA
Posts: 2
I have not noticed the smoke since we had the PCV valve changed and the oil service/regular maintenance. I am watching it closely though. My wife thinks I'm a nut job (maybe she's right??) since every time we go somewhere together and the truck is cold, as soon as I twist the key I run to the rear to look for the smoke. We've only put a few hundred miles on it since the service, so I can't comment yet on how much oil is being consumed. We're probably heading down to Florida next weekend and will pull my 17' boat w/ us. By the time we get back I will check the oil level to see where things stand. Stay tuned...
Reply With Quote Quick reply to this message
  #5  
Old 03-07-2011, 08:59 PM
Flying Monkey's Avatar
Flying Monkey Flying Monkey is offline
Member
 
2004 Chevy TrailBlazer LS
Dark Gray Metallic 4.2L I6 4X4
Join Date: Nov 2010
Location: Ringgold, GA
Posts: 256
usually its the sign of a worn valve guide but sometimes worn rings
__________________
Brooksphotodesign.net
Reply With Quote Quick reply to this message
  #6  
Old 03-07-2011, 10:19 PM
atv hauler atv hauler is offline
Junior Member
 
2006 Chevy TrailBlazer LT
Silverstone Metallic 5.3L V8 4X4
Join Date: Feb 2008
Location: Palmerston, ON
Posts: 81
I would lean towards leaky valve seals.
Reply With Quote Quick reply to this message
  #7  
Old 04-11-2012, 11:00 PM
Willie-TB Willie-TB is offline
Junior Member
 
2005 Chevy TrailBlazer LT EXT
Silverstone Metallic 5.3L V8 4X4
Join Date: Apr 2012
Location: Minnesota
Posts: 1
Hi All,

New member & first post - glad to be here!

Anyone know the TSB number of the PCV/Valve Cover fix mentioned in this thread?

My '05 TB with the 5.3 is doing the same thing @ 164K Miles. Runs good & still strong but is now drinking oil 1,000 miles after I had to replace a dead lifter on the other side ($1300!).

Not sure I want to do valve seals first or wish I would have done them when they had the motor apart before.

Is there a reliable way to diagnose worn valve seals?

Comments welcome - in the mean time I'm going to look around more on this site & chevy's for more on the TSB & PCV/valve cover fix.

Thanks All!

Willie
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


» Sponsors

Advertising Info

All times are GMT -4. The time now is 09:29 AM.


Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed