Hummer H3 For the Hummer driver who wants the rugged look and off road capabilities of the Hummer, but in a smaller size and with a more fuel economy friendly engine.

What would cause my rpms to drop to almost 500 and stay there with a rough idle

Old Oct 11, 2018 | 03:58 PM
  #1  
O7hummdinger's Avatar
Thread Starter
|
Junior Member
Joined: Jul 2018
Posts: 12
Default What would cause my rpms to drop to almost 500 and stay there with a rough idle


 
Old Oct 11, 2018 | 07:59 PM
  #2  
Bunger's Avatar
Senior Member
Joined: Sep 2009
Posts: 1,356
From: Connecticut
Default

Dirty Throttle Body and/or dirty MAF sensor.
Clean both before you do anything else.
 
Old Oct 12, 2018 | 08:35 AM
  #3  
TAINTER's Avatar
Senior Member
Joined: Sep 2008
Posts: 6,126
From: SE Michigan
Default

After what bunger said,
Intake leak, check to make sure ALL intake parts are secure from air box to throttle body.
The intake manifold (plastic) on top of the motor that has the throttle body bolted to, has bolts securing it to the motor.
On the I5 they sometimes work them self a little loose.
 
Old Oct 12, 2018 | 08:41 AM
  #4  
Doc Olds's Avatar
Super Moderator
Joined: Jul 2007
Posts: 13,101
From: Boat Town USA MI
Default

I agree with Bunger & Taint. After the easy stuff they mentioned, feel free to review this FAQ thread on topic.

Acts like it wants to stall/rough idle -No CEL -What To Do:
 
Old Oct 13, 2018 | 10:51 AM
  #5  
emetdw's Avatar
Member
Joined: Jul 2013
Posts: 71
Default

My H3T Alpha only likes Shell gas. In cold weather it idles rough on cold starts unless it has Shell in the tank. Super weird, and I’ve tried everything including Chevron, Costco, Safeway, Conoco, Texaco, etc., and Shell always works best. So now I’ve memorized where all the local Shell stations are, and Shell is in my quick search on Waze.
 
Old Feb 6, 2019 | 05:23 PM
  #6  
Bryan Oneal's Avatar
Junior Member
Joined: Feb 2013
Posts: 5
Default

hi did you ever find the rough idle issue? ive done all the recomends except check plastic intake
 
Old Feb 8, 2019 | 10:00 AM
  #7  
Doc Olds's Avatar
Super Moderator
Joined: Jul 2007
Posts: 13,101
From: Boat Town USA MI
Default

Originally Posted by Bryan Oneal
hi did you ever find the rough idle issue? ive done all the recomends except check plastic intake
Then, check the Intake Bolts and avoid repetitious questions. You saw my link back a few posts, click on it, and follow what it says. You now have your answer, click on the link.

Acts like it wants to stall/rough idle -No CEL -What To Do:

Ask your question in a new thread one time and wait for a response.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
H3-SC
PRIVATE For Sale / Trade Classifieds
14
Jul 15, 2019 06:54 AM
mcioci
PRIVATE For Sale / Trade Classifieds
4
Jun 14, 2019 07:05 PM
arcaro
PRIVATE For Sale / Trade Classifieds
5
Apr 19, 2016 12:15 AM
jvorpahl
PRIVATE For Sale / Trade Classifieds
29
Jan 13, 2014 03:31 PM
jdbaker73
PRIVATE For Sale / Trade Classifieds
11
Nov 27, 2011 01:36 PM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 10:31 PM.