Vacuum Leaks - Ususal Suspects

1999 GMC SIERRA
210,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
CHRISPASSEY1
  • MEMBER
  • 5 POSTS
I am having real trouble with my Truck. I keep on hearing from mechanics and other knowledgable people that my problem could be because of Vacuum leaks in the Engine.
Now I understand (basically) the theroy of what they are getting at, but could someone tell me what they specifically mean? Also, could you tell me where in the Engine should I look and how many places are there where the seal could be leaking?
I guess what I am asking is who are the usual suspects?
Finally, is there any place online where I can see a picture (system diagram) of what they are talking about?
Dec 8, 2010 at 5:43 PM
Advertisement
Avatar
DENNYP
  • CERTIFIED EXPERT
  • 1,824 POSTS
What is the problem you are having?
Dec 8, 2010 at 8:04 PM
Avatar
CHRISPASSEY1
  • MEMBER
  • 5 POSTS
The problem is that the Truck is stalling at a stop and it idling poorly. it almost sounds like it is choaking. I have replaced the Mass air filter, the spark plugs and ignition coils (I am not sure if the last two would be the cause) and I am hoping it isn't the catalytic converter. So before I hit that point, I decided to ask around and everyone I ask says it could be a vacuum leak. I just don't really know where to start.
Dec 8, 2010 at 9:38 PM
Advertisement
Avatar
DENNYP
  • CERTIFIED EXPERT
  • 1,824 POSTS
Start off by having it scanned for any trouble codes. If you don't have any codes, try cleaning the throttle body.
Use some throttle body cleaner and a toothbrush to scrub the carbon out of the inside of the throttle body opening.
Let me know if this helps.
Dec 9, 2010 at 1:36 AM
Avatar
CHRISPASSEY1
  • MEMBER
  • 5 POSTS
Thanks,
I will do that tonight and get back to you.

Thanks dennyp!
Dec 9, 2010 at 2:40 PM