Rough idle and bubbling noise under cab

Asked by Jan 19, 2017 at 11:34 PM about the 1991 GMC Sierra 1500 C1500 SLE Extended Cab LB

Question type: Maintenance & Repair

I have a 91 GMC Sierra 1500 5.0 .  It idles
rough at low speed sometimes  stalling .
Runs  fine  at a higher speed .  There's also
a bubbling noise under the cab  like it's
coming from the muffler . But the noise
doesn't always happen .  I have changed
the idle  control valve PCV valve and  fuel
filter .

2 Answers

120,075

Maybe you have a exhaust leak. Take it to a muffler shop. The rough idle could mean you need a tuneup or that the IAC is dirty or needs replacing.

What is the idle at? Maybe try running a can of sea foam through it

Your Answer:

GMC Sierra 1500 Experts

  • #1
    dragonflyoffshore
    Reputation
    5,640
  • #2
    John Saffrahn
    Reputation
    4,020
  • #3
    Glenn Clingenpeel
    Reputation
    3,780
View All

Related Models For Sale

Used Ford F-150
133 Great Deals out of 11,522 listings starting at $3,900
Used GMC Yukon
16 Great Deals out of 1,033 listings starting at $5,500
Used Chevrolet Camaro
13 Great Deals out of 916 listings starting at $11,500

Used Cars For Sale

2019 GMC Sierra 1500 For Sale
29 listings starting at $47,915
2018 GMC Sierra 1500 For Sale
12 Great Deals out of 8,092 listings starting at $26,275
2017 GMC Sierra 1500 For Sale
8 Great Deals out of 344 listings starting at $25,708
2016 GMC Sierra 1500 For Sale
16 Great Deals out of 367 listings starting at $21,750
2015 GMC Sierra 1500 For Sale
4 Great Deals out of 435 listings starting at $19,990

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.