Bigtickets

CEL came on this morning and gave me a P0507 Idle Control System RPM Higher Than Expected fault code. The car is idling at 800 to 1000 rpm even after it warmed up. Anybody have any experience with this? Thanks in advance for the help.

shardul

iTrader: (1)

there is a small rubber hose that goes over a metal tube by the fire wall. this hose get dislodged and will cause this error.

Bigtickets

SHARDUL--- you are the man. Problem solved. Is that a vacuum line of some sort??

shardul

iTrader: (1)

yes sir it is connected to the ICV

WesttxJR

I received the same error/symptoms recently. which hose was it? Thank you! JR

1970gsx

Post #2

WesttxJR

thanks! I read post #2 several times and it didn't quite help. I've also searched the threads, etc. Which hose is it? small? large? I try to not ask something without first physically checking, which I did, which is why I ask. thank you again.

shardul

iTrader: (1)

It is a small hose by the fuel line. You may not be able to see it with the air box on

WesttxJR

thanks Shardul. I found it. Your input is always appreciated.

Bigtickets

Did that fix it?

WesttxJR

Appears to be corrected. I found the proper hose, cleared out the code, and it didn't reappear today on the drive in. Car also idles a bit more smooth. Best, JR

AWH3

Had the same issue lately after a VC gasket change. the evaporative vacuum tube was knocked lose during the gasket replacement. it was the one that is secured to the grommet on the rear of the driver side valve cover. Unfortunately, you will most likely need to remove the air intakes to reattach to the vacuum tube. When this and other vacuum tubes crack or dislodge, you will get high idle codes as well as the dashboard errors indicating that the gas cap is not secure. when this happened to me, All of the above happened as well as the reserve fuel light even began to blink rapidly. I also think there are two other smaller vacuum tubes that are right above each of the valve covers that can also throw high idle codes if they are dislodged or cracked. There are many threads on this topic, just search for "vacuum tube", etc... Good Luck. Been there myself. The expertise on this forum is exceptional.

Bigtickets

I'm curious though, why would it cause the car to idle higher? At 30 mph the car would maintain speed on it's own.....

mercedes4ever

Upsets the air / fuel mixture.

AWH3

Disclaimer: i am not a mechanic, but have experienced these issues with my E55 and have done extensive research on the topic. I can tell you that any unmetered air introduced into the engine can cause high idle, rough idle, etc, which in turn will cause the car to downshift awkwardly when coming to a stop as well as throw messages on the dash display that indicates that your gas cap is not properly secured, etc. Any cracks or lose connection of these vacuum tubes can contribute to this behavior. I'll try to post some pics tomorrow for common leak locations.

AWH3

This is the location of the evap vacuum leak that caused me issues in the past. It's located towards the rear of the engine on the drivers side.

WesttxJR

The symptoms you listed are EXACTLY what I have experienced. The weird downshifts, etc. I think I'll tear in a little deeper this weekend and see what I find. How hard is it to remove the two metal chambers with AMG on them? Any weird tricks I should be aware of? Thanks for the pic! JR

berti_00

yah that bioootch did the same to me too and i poped it back in and CEL never came back and idle was tities

Karlson

Can that error code be due to ecu/tune error? I had 82mm with oe tunning and drove 500 miles without cel, as soon as put EC tune, CEL went on with 507 code.

Hulk

doubt it, that code is related to more mechanical than tune, tell Jerry about it, but that code means its seeing a vacuum leak, check around the tb and that metal tube

mht_v10

Just got my head gasket replaced and got the same P0507 code ... Traced the culprit and found out the metal tube isn't snug in , but can't find the metal grommet that hold that metal tube anywhere ... Even dealership don't have a clue about it. Anyone can help me to find that grommet ? Part number maybe ? Thanks in advance .

Shax Shux

Hello, could you be more specific about a tube on the firewall? All my hoses are connected well and have no cracks. Issue came up after I replaced head gaskets, I had to unplug all the hoses.

kevm14

I am only here to comment that with speed density there is no such thing as "unmetered air.". So vacuum leaks don't really change the mixture, just overall engine airflow.

Supercharge

Just had same dang issue after a VC. Little tough finding the hole in goes back in. At first I thought it had a hose connected to it. But it fits into a rubber plug with a hole in the center. Undone the e10 bolt holding it fished it back into its home and no more fast idle!! What would we do without the internet and forums! Thanks