My 2004 Jeep Limited 4x2 3.7 123,000 miles has a rough idle, I have changed the plugs anyone suggest the next steps to correct problem, I have no ck eng lite and I don't know how to check each cyl coils.

15

Asked by Apr 22, 2012 at 02:33 AM about the 2004 Jeep Liberty Limited

Question type: Maintenance & Repair

2 Answers

13,525

Sounds like a possible vacuum leak. The following test is a good indicator of several major engine components as indicated by the results. Here is a good reference for vacuum trouble shooting.......... You should get between 17-22 in. hg. at idle, depending on your elevation above 2000 feet MSL or mean sea level. To perform this test hook vacuum gauge directly to manifold vacuum. 1. Low steady needle usually indicates leaky intake, a leaky vacuum hose, late timing, or incorrect camshaft timing. 2. If reading is 3-8 inches low and fluctuates at that low reading suspect an intake manifold gasket leak at intake port or faulty injector. 3. If the needle has regular drops of about 2-4 in hg. at a steady rate the valves are probably leaking. (Perform a compression check). 4. An irregular drop or down flick of the needle can be caused by a sticking valve or an ignition misfire. 5. A rapid vibration of about four in hg. indicates worn valve guides. 6. Slight fluctuation of one inch or so indicates ignition problems. 7. Large fluctuation perform a compression check. 8. If needle moves slowly through a wide range check for PCV issues. Lastly watch the needle as you rev the engine slightly. The needle should drop then rise up to a maximum then settle back down to your idle reading. Hope this gives you a good place to start and helps you figure it out.

5 of 5 people found this helpful.
15

thanks I'll have to get a vacuum gage and ck it out

1 of 1 people found this helpful.

Your Answer

Jeep Liberty Experts

  • #1
    fixmyjeep
    Reputation
    1,490
  • #2
    rst429
    Reputation
    1,240
  • #3
    Tom Demyan
    Reputation
    1,230
View All

Related Models For Sale

Used Jeep Grand Cherokee
930 Great Deals out of 67,530 listings starting at $950
Used Jeep Wrangler
450 Great Deals out of 20,131 listings starting at $2,500
Used Ford Escape
1,263 Great Deals out of 98,845 listings starting at $1,000
Used Toyota RAV4
703 Great Deals out of 55,041 listings starting at $1,995
Used Honda CR-V
722 Great Deals out of 53,302 listings starting at $1,500
Used Ford F-150
3,206 Great Deals out of 226,353 listings starting at $1,250
Used Ford Explorer
1,156 Great Deals out of 64,840 listings starting at $1,200
Used Nissan Xterra
79 Great Deals out of 3,317 listings starting at $1,995

Used Cars For Sale

2012 Jeep Liberty Limited For Sale
24 listings starting at $7,900
2011 Jeep Liberty Limited For Sale
33 listings starting at $9,490
2010 Jeep Liberty Limited For Sale
12 listings starting at $9,499
2009 Jeep Liberty Limited For Sale
14 listings starting at $6,995
2008 Jeep Liberty Limited For Sale
3 Great Deals out of 55 listings starting at $3,950

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.