High Idle @ 1500rpm when car warm/hot, won't kick down below 1000rpm until put in D gear


Asked by Jun 13, 2012 at 02:46 AM about the 1991 Mercedes-Benz 300-Class 4 Dr 300E Sedan

Question type: Maintenance & Repair

Been experiencing a high idle issue when my 91 300E is warm/hot. Revs up to 1500rpm and will rev down to 1000rpm when hit the gas pedal but will climb back right back up to 1500 and stay until put in D gear. Any advice?

2 Answers


most common is vacuum leak,could be any hose on intake,idle motor might be stuck,but I would check for leaks first,inspect,and listen for hissing noise,to only rev it up 800 rpm its probably small.

ever resolve the issue?

Your Answer

Mercedes-Benz 300-Class Experts

  • #1
    James Ramond
  • #2
    Tom Demyan
  • #3
View All

Related Models For Sale

Used BMW 3 Series
902 Great Deals out of 32,870 listings starting at $1,000
Used Mercedes-Benz G-Class
5 Great Deals out of 1,198 listings starting at $24,950
Used Mercedes-Benz SL-Class
51 Great Deals out of 3,205 listings starting at $4,930

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.