Weird idle problems..
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AudiWorld Member
Joined: Oct 2003
Posts: 291
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Weird idle problems..
I'm having weird idle problems. Up and down, and sometimes it dies. Aside from the ICV and replacing the ECT sensor, what could it be? What should I clean? I've been searching the list and it looks like maybe replace my O2 sensors? clean the throttle plate? Seafoam?
Comments??
Comments??
AudiWorld Super User
Joined: Jan 2003
Posts: 9,298
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If you haven't replaced the vacuum hoses during the past 4 years or so...
chances are you got some leaky ones. It's a good idea to prophylactically replace all thin vacuum lines every few years. Vacuum hoses that are closer to hot spots go bad the quickest.
Vacuum leaks are not only due to leaky hoses, but also due to leaky gaskets, for example the plenum-to-throttle body gasket, or due to cracked valve cover breather hoses. Sometimes a vacuum hose pops off and goes unnoticed (plenum to TB!).
Sometimes you can hear a bad vacuum leak. Spraying carb cleaner around a leaky gasket (with the engine running) will result in a change in idle and thus identify a leak. Really bad vacuum leaks can trigger a "lean condition" code.
I'd start with replacing all vacuum lines (people seem to like BMW vac hose best as replacement) and a thorough visual inspection.
A loping idle can also be due to compound issues. Vacuum leaks, a dirty or defective ICV, bad spark plugs wires or spark plugs, and even a less then pristine MAF sensor can contribute to poor idle.
Vacuum leaks are not only due to leaky hoses, but also due to leaky gaskets, for example the plenum-to-throttle body gasket, or due to cracked valve cover breather hoses. Sometimes a vacuum hose pops off and goes unnoticed (plenum to TB!).
Sometimes you can hear a bad vacuum leak. Spraying carb cleaner around a leaky gasket (with the engine running) will result in a change in idle and thus identify a leak. Really bad vacuum leaks can trigger a "lean condition" code.
I'd start with replacing all vacuum lines (people seem to like BMW vac hose best as replacement) and a thorough visual inspection.
A loping idle can also be due to compound issues. Vacuum leaks, a dirty or defective ICV, bad spark plugs wires or spark plugs, and even a less then pristine MAF sensor can contribute to poor idle.
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