I did a search and didn't come up with the information I was looking for.


I have a 96 420a 5 spd. When I drive and come to a stop (pressing in the clutch) my idle will not drop to normal levels, instead dropping to about 1100-1000 rpm. And it doesn't drop to 800 until I come to a complete stop. I read somewhere that it could be from a faulty speed sensor. Anybody else ever have this problem or can confirm this theory? And where do I find my speed sensor?


Thanks guys!

Had same problem once, ended up being faulty PCV that was taking some time to close. But could also be that, vacuum leak, idle control valve.

Normal. Move on. Next?

Originally posted by DarkOne
Normal. Move on. Next?

Wow! Your a helpful one.

Originally posted by Slammed0

Originally posted by DarkOne Normal. Move on. Next?

Wow! Your a helpful one.

I find your sarcasm irritating. It's normal behavior, they all do it, there's nothing to fix and nothing is failing. What more can you possibly expect me to tell you?

Yes, this is a normal condition and it should be like this. It's believed that this happens because when you have your foot off the gas, and on the brakes, the higher rpm with no load on the engine, creates a higher vacuum signal. This assists with braking ease since the increased vacuum works the brake booster better, which makes pushing on the brake pedal easier and with less effort.

Originally posted by DarkOne

Originally posted by Slammed0

Originally posted by DarkOne Normal. Move on. Next?

Wow! Your a helpful one.

I find your sarcasm irritating. It's normal behavior, they all do it, there's nothing to fix and nothing is failing. What more can you possibly expect me to tell you?

Well I kind of found your short answer irritating so I guess we're even.

Thanks though for your help and also everybody else for your help too. I appreciate it. I am still learning about DSMs.