Mercedes-Benz C240 Engine idle speed is high Inspection at your home or office.

Our certified mobile mechanics come to you 7 days a week between 7 AM and 9 PM.

Estimate price near me

Service Location

Customer Ratings

(125)

How A Diagnostic Works

Instantly book a certified mobile mechanic to come to you

Mechanic diagnoses the problem and quotes necessary repairs

Your vehicle is ready to go

Fair, upfront & transparent pricing for all services

Our certified mobile mechanics can come to you now.

Customer Ratings

(125)

Engine idle speed is high Inspection Service

How much does a Engine idle speed is high Inspection cost?

On average, the cost for a Mercedes-Benz C240 Engine idle speed is high Inspection is $95 with $0 for parts and $95 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
2002 Mercedes-Benz C240V6-2.6LService typeEngine idle speed is high InspectionEstimate$114.99Shop/Dealer Price$132.49 - $145.62
2004 Mercedes-Benz C240V6-2.6LService typeEngine idle speed is high InspectionEstimate$94.99Shop/Dealer Price$112.52 - $125.67
2001 Mercedes-Benz C240V6-2.6LService typeEngine idle speed is high InspectionEstimate$94.99Shop/Dealer Price$112.52 - $125.67
2005 Mercedes-Benz C240V6-2.6LService typeEngine idle speed is high InspectionEstimate$94.99Shop/Dealer Price$112.48 - $125.60
2003 Mercedes-Benz C240V6-2.6LService typeEngine idle speed is high InspectionEstimate$94.99Shop/Dealer Price$112.55 - $125.72
Show example Mercedes-Benz C240 Engine idle speed is high Inspection prices

What is engine idle speed and how is it maintained?

Engine idle speed is the speed, measured in revolutions per minute (RPM) an engine is designed to run at when the engine is fully warmed up and the vehicle is stopped in park or neutral. Typically, the idle speed will be set at a value in the range of 600 to 800 RPM, but the exact value will depend on the number of engine cylinders and whether the vehicle is equipped with a manual or automatic transmission. Idle speed is maintained by the throttle body working in conjunction with the vehicle’s powertrain control module.

When to check for idle speed issues:

  • RPM on dash gauge does not match OEM specification. Many cars have RPM gauges. If the engine speed displayed on the gauge does not match the original equipment manufacturer (OEM) specification on the underhood label, there is probably something wrong.
  • Engine is idling higher than normal. If there is no RPM gauge but the engine sounds like it is turning faster when idle, a mechanic can use an instrument to measure the actual engine speed.
  • Harsh engagement in drive. If the idle speed is too high, the vehicle will jump forward when placed in drive.
  • Excessive brake effort is required to hold vehicle at a stop. If idle speed is normal, only a very light force on the brake pedal will be necessary to prevent forward motion in drive.

How do mechanics adjust or repair incorrect idle speed?

The repair procedure depends on the exact cause of the high idle. The below lists common causes of high idle and in each case, the appropriate vehicle system, components, and parts involved would be inspected, removed for repairs, and/or replaced as needed.

Faulty Fuse: In the majority of vehicles, engine idle speed is controlled via an idle control valve (ICV). A faulty or blown fuse in other electronically controlled systems can cause the Idle Air Control (IAC) motor to malfunction, leading to a higher than normal engine idle speed.

Faulty Idle Air Control Valve (ICV): Some cars are equipped with an idle air control valve to maintain idle speed. This part can malfunction due to excessive carbon buildup in the intake manifold.

Vacuum Leak: On any engine, a vacuum leak will cause a high engine idle as the oxygen sensor detects lean operation and the engine computer then tries to compensate, which can result in abnormal idle. Malfunctioning Throttle: A malfunctioning throttle system can cause both a high or low idle as well as an engine stall. A dirty air intake or cracked air intake tube is often the culprit. Computer Malfunction: If the powertrain control module is malfunctioning, idle speed may be affected.

Is it safe to drive with incorrect idle speed?

No. High idle speed could make your vehicle difficult to control and were the idle speed to suddenly and unexpectedly increase to really high levels, you could experience unintended acceleration. Even moderately high idle speed, that is up to 1,200 RPM will make it more difficult to slow your vehicle when stopping and, once stopped, there remains the risk of your foot coming off the brake and the car jumping ahead. High idle speed also wastes gas and can be distracting as the vehicle does not perform as expected.

When addressing idle speed issues, keep in mind:

  • Related functions, such as the idle up function when the air conditioner is turned on, will be inspected by a mechanic during the repair of a high idle problem.
  • Prior to replacing parts, such as the throttle body, the mechanic will also need to rule out electrical causes of incorrect idle speed as well as physical causes such as vacuum leaks.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee


Meet some of our expert Mercedes-Benz mechanics

Real customer reviews from Mercedes-Benz owners like you.

Excellent Rating

(125)

Rating Summary
118
4
2
1
0
118
4
2
1
0

Matthew

33 years of experience
1229 reviews
Matthew
33 years of experience
Mercedes-Benz C240 V6-2.6L - Fuel Pump - Newport News, Virginia
Great personality greeted me with a warm welcoming! Explain what he would be doing, and his experience! After he did the 50 point inspection I feel he may have mistaken diagnosed my water pump! It has no leaks and it isn’t cracked not sure we’re that came from. I drove my car after Matt replaced the fuel pump and I took it to the Mercedes dealer the pulley has 4 nuts and bults one was lose and they just tighten it up for me ! Other than that Great service!

Ronald

41 years of experience
313 reviews
Ronald
41 years of experience
Mercedes-Benz C240 V6-2.6L - Not able to change gears - Houston, Texas
Very knowledgeable and friendly. Great customer service.

Artem

12 years of experience
55 reviews
Artem
12 years of experience
Mercedes-Benz C240 V6-2.6L - Back To School Promo - Walnut Creek, California
After rescheduling twice, he showed up at 4:45 for a 4-4:30 appointment. He was a little sloppy and left oil stains on pavement. He was also covered in grease from prior appointment, so i asked him not to test drive the car as he would have soiled the beige leather interior.

Andrew

12 years of experience
29 reviews
Andrew
12 years of experience
Mercedes-Benz C240 V6-2.6L - Car is not starting - Cape Coral, Florida
Amazing!

Excellent Rating

(125)

Rating Summary
118
4
2
1
0
118
4
2
1
0
Number of Mercedes-Benz C240 services completed
1375+
services done by our mechanics
TOTAL NUMBER OF EXPERT Mercedes-Benz MECHANICS
1100+
experts on our platform

Recent articles & questions

Cell Phones and Texting: Distracted Driving Laws in Massachusetts
Massachusetts Massachusetts has a statewide ban on texting for drivers of all ages. Drivers under the age of 18 who hold a learner’s permit or provisional license are considered Junior Operators and are not allowed to use a cell phone...
How to Replace a Lost or Stolen Car Title in Colorado
Your Your car’s title proves your ownership of the vehicle, and it’s required for a number of different things. You won’t be able to sell the car without a title, and you can’t trade it in either. If you move...
P3468 OBD-11 Trouble Code: Cylinder 9 Deactivation/Intake Valve Control Circuit High
What What the P3468 code means This code indicates that there is a problem with the intake valve on cylinder number 9. When your vehicle’s powertrain control module (PCM) notices that the measured values of the mass airflow sensor, the...

Radiator hose pops off

The cooling system would need to be opened to see if, when the engine is cranked, the combustion of the engine is pressurizing the cooling system, and blowing off the hose. The head gasket may be blown. I recommend having...

How much does it cost to teplace fuel injector in 2003 ford ranger, is it something i could do myself

Hi...the Trouble Code that sets if a fuel injector malfunctions does not provide a diagnostic identifying the cause of the injector failure. Consequently, the injector itself has to be directly tested. You could, for example, have a situation where the...

Why is my car making this clicking noise when accelerating past 40

Hi Boom. Thanks for contacting us tonight. Sometimes when a vehicle runs fine until it reaches 40 mph, the problem is in the ECU, or ignition timing department. When multiple services are completed, it's possible for error codes to be...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com