[FIXED] Audi A4 RPM Idle Problem

*** UPDATE ***

So it turns out that the ignition coil on the 3rd cylinder broke in half. Yes, you read that right; the damn thing broke in half...probably due to the poor quality of these things. These coils are made by Bremi, the same company that prompted an ignition coil recall by Audi.

All I can say is this: "Fuck you, Bremi."

-------------------------

The Tachometer on my 2005 Audi A4 1.8T shows the RPM's fluctuating when the engine is idle.

When I start the car up, it will idle, and sometimes the rpm will drop to 600 rpm. Even when the car is warm/hot from running, I will come to a stop, in drive, foot on the brake, and sometimes the engine rpm will decrease from 800/900 rpm to 600 rpm or less, and then immediately rev back up to idle speed.

This is very intermittent and doesn't seem to follow a trend; just does it sporadically. But the car drives fine, accelerates fine, and never has an issue with fuel or rpm reduction any other time.

- Could this be cold weather related (it's currently between -5 and -1 deg C outside)?
- Or is this a sign of a bad Idle Control/Stabilizer Valve?
- Or perhaps there is a problem with the MAF sensor?
- Or maybe the ECU?

What would cause the engine to drop rpm's at idle, but bring it right back to idle when it happens? Anyone else have this issue?

Category:

Autos & Vehicles

Tags:

• Audi
• A4
• 1.8T
• Tach
• RPM
• Problems
• engine
• ignition
• coil
• bremi
• recall

[dustatios]

Try turning your air con off and then see if it still does it

[RickyTomatoes]

@dustatios Please see my update in the video description.

[Mushu0987]

You're so dumb.

[Rangerscott69]

My vehicle's engine does the same sometimes. It'll also dip to 400rpms when coming to a stop some times. I was told to see if my IAC (idle air control) valve is gunked up.

It should be on the intake or on the throttlebody.