P0507- Idle Air Control(RPM Higher Than Expected)

April 1, 2019MechVibesblog

P0507- RPM higher than expected is an OBD II generic trouble code derived as a result of Higher rpm readings. This code is triggered when engine Idle speed is higher than it desired rate set by the manufacturer.

This prevents vehicle to perform well. In most cases it gives a hard drive since rpm is not set at desired rate allowing engine to stumble and having related backfire issues.

In this lesson, we will cover up major ways on how to diagnose this trouble code and step by step guide to follow to solve this issue.


P0300- Random Misfire Detected

Symptoms Of P0507-RPM Higher Than Expected

Here will take a deep look into major symptoms of P0507 generic OBD II trouble code.

MIL(Malfunction Indicator Lamp)

This is also referred to as Check Engine light, is an engine management system computerized to help indicate a malfunction.

There will be false readings and values sent to the ECU and other modules due to higher rpm.

This calls for check engine light on dashboard prompting you the vehicle is not in a good condition and needs an appropriate response.

RPM Rises at Idle

If critically examined, you will find out rpm rises and falls back continuously when engine is run at idle. This allows the vehicle to act abnormal and there will be false readings sent to ECU as well.

Vacuum Leak Sound

Another symptom to notice is, there will be a vacuum leak sound around the inlet manifold.

This sound very tricky and had to find where is particularly coming from. It really sounds like a blown whistle.

This begins as soon as vehicle is turn on and stays on as long as engine runs.

Oil Spillage and Leaks

There will be oil leaks around engine valve cover and cylinder head. Since there is oil leak, then definitely there will be high oil consumption.

You will also notice there are few oil leaks around spark plug holes, go ahead and take one ignition coil out, you will notice what am trying to figure out.


How To Diagnose Black Exhaust Smoke

Causes and Solutions of P0507-RPM Higher Than Expected

Diagnosing this fault code can be very embarrassing which requires much attention and deep research before you proceed with any repairs or parts disassembly.

Most people complain of this issue , they go ahead and change in few things but it couldn’t work out. You need to gather enough resource and finds before proceeding.

Let’s take a deep dive on major causes on this code and how to quickly solve this issue.

Faulty PCV Valve

PCV also known as Positive Crankcase Ventilation. This maintains the level of vacuum in the crankcase. It also helps to regulate the amount of airflow in the engine to prevent oil sludge and high consumption.

Engine vacuum is very high when run at idle, which draws much oil from the engine and regulate the amount of vacuum applied.

Therefore, a faulty PCV valve can cause vehicle rpm to rise higher than expected mostly when idle. Check for bad PCV valve.

Most vehicle have their PCV valve design addition with the valve cover and needs to be check as well.

High Oil Consumption

There will be high oil consumption and leaks due to bad seals and faulty PCV valve. Oil will be leaking around valve cover area and spark plug holes.

This is a sign of back pressure since there is no air flow. Check for bad seals.

Vacuum Leak

Another cause of rpm rise than expected is due to vacuum leak. Air mainly help vehicle perform better and holds pressure. You can go ahead and perform vacuum leak test if you the tool to do so.

It makes engine to stumble, air leaks are noticed around the intake manifold . Check for further leaks as well and get it fix if detected.

Idle Control Valve

These valves are purposely built in fuel injection cars to help control the engines idling speed.

They mostly get damaged and begins to give false reading triggering this trouble code. This cause vehicle’s rpm to rise up and down.

Loose contact with the harness can also cause this, check for faulty sensor, fix new one if other seems not work.

Faulty MAF Sensor

This is also known as Mass Airflow Sensor(air mass). It reads the amount of air running through the engine. The vehicle needs right or desired amount of air to complete combustion fully.

When theses sensors fails, the mostly reduce the expected air needed for a complete combustion, which cause vehicle to act abnormal. These mostly rises the rpm when idle and also gives vehicle a difficult start.

Replacing faulty MAF sensor can be a step further in diagnosing this trouble code.


AFS (Adaptive Front-Lightning System)

Throttle Body

These are found in modern fuel injected cars which helps to control the amount of air flowing through the engine. There is a flap which opens and closes controlling the passage of air.

A faulty throttle body can cause slow actuation, flap hardly opens and close at it desired rate. This cause vehicle to stumble and rpm rises higher than expected.

Few ways to check if throttle is faulty is by probing it to check if it stays open and close. Also check for harness, they often loose contact.

They also get choked with carbon and debris. Clean throttle with choke spray for a healthy engine.

Prev Post


Mercedes Benz Oil Reset

March 31, 2019

Next Post


Piston Rings and How They Work

April 2, 2019