Uneasy idle

[Rish///M]

Hi Guys,

Need some assistance. I just bought a E46 318i A/T 2004. Car is superclean, BMW confirmed no major issues.

When I test drove the car yesterday with the AC on the idle was fine. Today when I picked up the car and drove for a while with the AC off, the idle is very low & unsteady. Put the AC back on and its fine.

What might be the issue here?

 

[335stepitup]

Congrats on your purchase.
Easy to fix...keep your AC on lol

Srsly though it could be a number of things, but most probably just needs the "idle speed with AC off" raised and a good ol fashioned italian tune-up.
Common on those engines where also crankcase vent valve failure which causes erratic idling. To test if it's ok idle the engine for a few minutes then open the oil filler cap, if you feel suction holding the cap in place as you remove it the vent valve is in need of replacement.

Hi Guys,

Need some assistance. I just bought a E46 318i A/T 2004. Car is superclean, BMW confirmed no major issues.

When I test drove the car yesterday with the AC on the idle was fine. Today when I picked up the car and drove for a while with the AC off, the idle is very low & unsteady. Put the AC back on and its fine.

What might be the issue here?

 

[Mike1]

Try an Injector Cleaner... Oftens cures unsteady or irratic idle.

Worked for me. :wave:

 

[zaleonardz]

You had unsteady or irratic idle Mike ?

 

[Mike1]

Hahaha no... My Ford did. :clap:

 

[Rish///M]

Congrats on your purchase.
Easy to fix...keep your AC on lol

Srsly though it could be a number of things, but most probably just needs the "idle speed with AC off" raised and a good ol fashioned italian tune-up.
Common on those engines where also crankcase vent valve failure which causes erratic idling. To test if it's ok idle the engine for a few minutes then open the oil filler cap, if you feel suction holding the cap in place as you remove it the vent valve is in need of replacement.

Hi Guys,

Need some assistance. I just bought a E46 318i A/T 2004. Car is superclean, BMW confirmed no major issues.

When I test drove the car yesterday with the AC on the idle was fine. Today when I picked up the car and drove for a while with the AC off, the idle is very low & unsteady. Put the AC back on and its fine.

What might be the issue here?

Thanks 335s......
As I followed your instruction there was suction on the oil cap as I removed it.
Where can I get this sorted and tuned up? BMW? Any other recommendations in Jhb?

@ Mike, I will try the injector cleaner as well. Any preferred brand?

Thanks guys

 

[335stepitup]

Ok so the problem is the crank vent valve then..
Have been out of the josies scene for a while now so can only recommend dealers, though any BMW specialist worth his salt would be able to replace the crank vent valve very easily as well as give it a quick tune. I have sent you a PM with some1's email from the east rand, you could check him out if you live around there..very experienced guy.

Congrats on your purchase.
Easy to fix...keep your AC on lol

Srsly though it could be a number of things, but most probably just needs the "idle speed with AC off" raised and a good ol fashioned italian tune-up.
Common on those engines where also crankcase vent valve failure which causes erratic idling. To test if it's ok idle the engine for a few minutes then open the oil filler cap, if you feel suction holding the cap in place as you remove it the vent valve is in need of replacement.

Hi Guys,

Need some assistance. I just bought a E46 318i A/T 2004. Car is superclean, BMW confirmed no major issues.

When I test drove the car yesterday with the AC on the idle was fine. Today when I picked up the car and drove for a while with the AC off, the idle is very low & unsteady. Put the AC back on and its fine.

What might be the issue here?

Thanks 335s......
As I followed your instruction there was suction on the oil cap as I removed it.
Where can I get this sorted and tuned up? BMW? Any other recommendations in Jhb?

@ Mike, I will try the injector cleaner as well. Any preferred brand?

Thanks guys