03 Envoy 4.2 Signfantly loses power uphill - Page 2 - 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 > General TrailVoy Discussion > The "How-To" and DIY Section

The "How-To" and DIY Section Threads on Do-It-Yourself and How-To goes here.

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools
  #11  
Old 07-24-2019, 08:22 PM
Monte27 Monte27 is offline
Junior Member
 
2003 GMC Envoy SLE
Fire Red 4.2L I6 4X4
Join Date: Jul 2019
Location: Big Island, Hawaii
Posts: 9
Quote:
Originally Posted by PalmBay04TB View Post
My 04Tb with 220k miles had same probs, it was a plugged up cat convertor, was just clear enough to run but was running real hot and weak....put on new cat and its like a new truck again.
That symptoms sounds just like mine. Only got 160k on it, so I'm still hopin its not the cat. Thanks, and have a great day
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #12  
Old 07-24-2019, 08:28 PM
Monte27 Monte27 is offline
Junior Member
 
2003 GMC Envoy SLE
Fire Red 4.2L I6 4X4
Join Date: Jul 2019
Location: Big Island, Hawaii
Posts: 9
Quote:
Originally Posted by RPatton76 View Post
It is not likely an evap issue should affect power, especially if you're revving it much. When my other car cats died, the first one broke into small pieces and plugged up the 2nd cat and made power and mileage suffer and, though I didn't notice it, it was getting a quieter exhaust at the time. After changing cats, the exhaust sound came back to normal. Mileage was also going down at the time. If your problem is really that the motor gets too hot, I'd put in a new thermostat and maybe go down to the next lower temperature, and be sure to burp out any air that may cause overheating.

Rob in AZ
Thanx Rob, Just waitin for the thermostat. Parts store had to bring it in. Getting it in an hour, and praying its the cause. Have a good evening. Aloha from Hawai'i
Reply With Quote Quick reply to this message
  #13  
Old 07-24-2019, 10:09 PM
keenxxx keenxxx is offline
Junior Member
 
2005 Buick Rainier
Black 5.3L V8 AWD
Join Date: Oct 2013
Location: sf
Posts: 10
Power loss - you will need to verify fuel trim & O2 sensor readings during power loss on a scan tool. A clogged catalytic converter could cause power loss. Check w/ a back pressure gauge usually into the O2 hole. I work in a shop and realize DIY guys donít have all the proper tools but blindly hanging parts is a waste of time and $.
Reply With Quote Quick reply to this message
 
  #14  
Old 07-25-2019, 06:40 AM
junkyardog junkyardog is offline
Junior Member
 
2004 Chevy TrailBlazer LS
Graystone Metallic 4.2L I6 4X4
Join Date: Feb 2008
Location: Lansdale, Pa.
Posts: 20
Power loss

Definitely is the CAT. I had this exact same issue 2 years ago... I will pulling a small trailer and about an hour into my trip, going up a hill, I lost all kinds of power; had to go into the shoulder because I couldn't go past 30 MPH. After it cooled down a bit, it was OK, but came back again once I started driving. Went to my tranny place thinking it was the trans and shop said replaced the CAT and all good.. It's been good since... Mike
Reply With Quote Quick reply to this message
  #15  
Old 07-25-2019, 07:52 AM
Jkb242 Jkb242 is offline
Junior Member
 
2006 GMC Envoy Denali
pewter 5.3L V8 2WD
Join Date: Nov 2014
Location: Orange Co, CA
Posts: 68
Sounds like you have some very solid advice not surprising however. Regarding the over heating, unless there is excessive back pressure from what sounds like an agreement on the CAT, the over heating could be a separate issue. Hopefully you have never mixed Dexcol with the green stuff regular antifreeze. The reaction between the two is the production of harden deposits throughout the system. Otherwise, I think the thermostat is a good suggestion. Make sure the engine side of the radiator find not crushed from previous work like from a water pump replacement. If you keep it long enough you will have to change it however, DO NOT USE ANYTHING BUT ORIGINAL AC DELCO! Otherwise, youíll likely be doing the replacement AGAIN within a year!

Best of luck!!
__________________
[B]Advertising exploits inverse logic where marketing wank highlights deficiencies rather than strengths.[/B]
Reply With Quote Quick reply to this message
  #16  
Old 07-25-2019, 08:23 AM
zoysia zoysia is offline
Junior Member
 
Join Date: Dec 2018
Posts: 9
I had same “no power on hills” with my ‘02. It was due to a partially blocked muffler. My son had been rear-ended on a snowy road and exhaust pipe shove creased muffler.
Reply With Quote Quick reply to this message
  #17  
Old 07-25-2019, 10:57 AM
Monte27 Monte27 is offline
Junior Member
 
2003 GMC Envoy SLE
Fire Red 4.2L I6 4X4
Join Date: Jul 2019
Location: Big Island, Hawaii
Posts: 9
Thanks Guys. Parts store didn't get me the thermostat yesterday, so I'll have to wait till this afternoon for that. But I guess majority feels its the cat, and I guess that explains the low Boggin sound in engine when theres no power. Sounds like a 4 barrel that is badly adjusted and just dieng for fuel. I will let you folks know the outcome. Thanks again to all. Have a great day
Reply With Quote Quick reply to this message
  #18  
Old 07-25-2019, 01:45 PM
RPatton76 RPatton76 is offline
New Member
 
2008 Chevy TrailBlazer LT
Imperial Blue Metallic 4.2L I6 2WD
Join Date: Apr 2017
Location: Phoenix, AZ
Posts: 48
When I was breaking in a cam on a V-6 S-10, I swapped 2 spark plug wires but drove it that way for a half hour and then saw the glowing red hot catalytic converter. Boy did it have some major power, after hollowing that out! So, if you drive it long and fast enough in the dark, you can see if a cat is glowing if you can stop fast enough and get out and look. If it is getting *that* hot....

Rob in AZ
Reply With Quote Quick reply to this message
  #19  
Old 07-27-2019, 05:16 PM
Monte27 Monte27 is offline
Junior Member
 
2003 GMC Envoy SLE
Fire Red 4.2L I6 4X4
Join Date: Jul 2019
Location: Big Island, Hawaii
Posts: 9
Well guys, heres where I'm at...Bypassed the cat... same problem. Someone told me the rubbish from the cat could have been plugging the muffller so I removed muffler and still ran the same. When parked I gradually take rpms up to 3k with no miss at any level, and it revs without bogging. On the road...slow acceleration, crawls on the up hill and motor sounds like its a 4 barrel with a big time boggin issue.
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:
Location
Where you live (ex: Philadephia, PA)
Vehicle Year
Choose your year
Or enter your choice here:
Vehicle Color
Choose your factory color (Custom, Not Listed & Two-Tones; Use Text Field Below)
Or enter your choice here:
Vehicle Make
Choose your make
Or enter your choice here:
Vehicle Model
Choose your model
Or enter your choice here:
Vehicle Engine
Choose your engine
Vehicle Drivetrain
Choose your vehicle drivetrain
Security Question
Fill in the blanks: Tra___oy
Insurance
Please select your insurance company (Optional)

Log-in



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 08:15 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