Why does my grand marquis idle rough in park?

Asked by Guru9ZH2N1 Dec 08, 2020 at 12:14 PM about the 1988 Mercury Grand Marquis

Question type: Maintenance & Repair

Why does my my 1988 grand marquis idle rough in  
park but acts fine when I press the gas

2 Answers

27,530

The basics for a rough idle, check for a leak of some kind, fuel--egr--vacuum. Check and clean anything that has to do with idle air system. Clean throttle bore and around throttle plate, see if it helps.

There is a vacuum leak but I cant find it, when I put it in park you can hear it, then goes away when I press the gas

Your Answer:

CarGurus Experts

  • #1
    Tracy Hooks
    Reputation
    9,850
  • #2
    Trippmeister
    Reputation
    5,140
  • #3
    Bob Beaman
    Reputation
    3,880
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Ford Crown Victoria
5 listings starting at $8,000
Used Ford F-150
323 Great Deals out of 15,226 listings starting at $3,295
Used Ford Mustang
42 Great Deals out of 1,255 listings starting at $4,995
Used Honda Accord
40 Great Deals out of 909 listings starting at $2,799
Used Lincoln Continental
4 Great Deals out of 12 listings starting at $17,900
Used Dodge Charger
36 Great Deals out of 626 listings starting at $4,888
Used Chevrolet Camaro
21 Great Deals out of 321 listings starting at $10,500

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. Content will be removed if CarGurus becomes aware that it violates our policies.