[Raptor3DPilot]

As the title states, I have an 06 330i with 70k miles on it. I am at about 6500miles since my last oil change and am getting ready to do it this weekend.

On my last oil change, I had the P1554 (VANOS) code show up prior to the oil change. I removed both solenoids and cleaned them with carb cleaner and dried them out with compressed air. The P1554 codes never came back.

Now that I am near another oil change, I have noticed that my car is beginning to idle "rough" at times when the AC is on and at a stoplight (in gear). The RPMs will drop 50-100rpm and then increase 100-200rpm. It feels like the car is going to stall, but it hasn't yet. I've checked the codes using my code reader and everything comes up clear.

I've read that the rough idle could be an indicator of the VANOS solenoids. My question is, should I remove and re-clean the solenoids, or should I just replace them ($150 each)?

Any other thoughts on what could cause this? No issues are noticed while driving the car, only when it's at a stoplight, AC on, and in gear.

Thanks for any tips!!

[330iE90spt]

You may want to give some more info. on the maintenance of your car. Have spark plugs been replaced? Coil packs? How old is the battery?

[GoRomeo]

Did you swap your vanos from top to bottom after you cleaned them? This is recommended.

I agree with post above. Check your battery. Although, 70k miles may be a bit overkilled for spark plugs its getting closed to 100k which is time to change them as suggested by BMW on N52 engines. I would start by adding techron fuel system cleaner and go from there.

[Raptor3DPilot]

I just purchased the car in Dec 2012, so I am not sure of the exact maintenance that was performed. A few months after I purchased it, the water pump failed (seems normal around 60+k), so I replaced it and the thermostat. I do not believe the spark plugs have been changed yet. I'll have to check the battery when I get home to see the date on it.

I did not swap the vanos the first time, I just removed both of them one at a time and cleaned them. The codes never returned once I cleaned them, so I figured the cleaning was good enough.

I'll add some techron fuel system cleaner. I also only use 91 octane gasoline from Shell (unless I'm not near one and have to use something else).

I'll also check the airbox to ensure the filter is clean of debri.

My car looks exactly like yours GoRomeo.

My passenger side mirror also gave me trouble shortly after I bought it, but I just got it to a position that worked for me and unplugged it. lol.

Other than that, it's a great car!!

[GoRomeo]

Cool bro, yeah Air filter is good to check as well. You should replace it anyways its only about 20.00. Also, clean you MAF sensor with the MAF sensor cleaner. I did this along with charcoal filter delete e90 (google it if you dont know about it) and my car has been running great ever since.

Yeah its a our car I think is great color, and hope you got sport and premium packages. Its a must!!

I bought mine in early 06 and still getting compliments from people. I changed my 162 rims for 189s fully stock. Love it!

[Raptor3DPilot]

I will have to take a look at the charcoal filter delete, haven't heard anything about that.

Yeah, it has the sport and premium packages. I don't get to drive it that much, the wife usually takes it while I take the Armada.

Which wheels are in your avatar picture? Those are the exact style that I have and I really like them compared to the other BMW wheels that I've seen.

My wife did clip a pretty large rock on the freeway and tore a 1in gash in the RFT, that one stung a little bit, but luckily the other tires were fairly new, so I only had to replace the one.

[GoRomeo]

I see.

THe ones you see in the avatar picture are the 162 which are the ones it came with. I sold them and bought 189s which 335s coupe came out with in 07 and up. So it gave my car even newer look.

In regards to RFT lots of people dont like then due to stiff walls and pricey. Roads here in San Diego are not bad so having RFT dont bother me. I always find a good deal on them locally or online.

[Three_thirty_I]

All things mentioned already, plus might to a small degree be an eccentric shaft sensor issue if nothing else works. But I would clean the Vanos solenoids again - I soaked them in unleaded petrol for a few hours, then once dried, dipped in fresh engine oil as per what the engine has before reinstalling... I haven't swapped mine around, but have heard that this is a good thing to do. Other things mentioned too, failing coil packs or worn spark plugs can cause a rough idle, so worth looking at when last the spark plugs were replaced (should have been done at 60k miles or so). Definitely worth cleaning the MAF which is easy to do, but make sure you have a good quality MAF cleaner and use as directed, and allow to dry thoroughly before reinstalling. For good measure, run a tank of fuel with a good injector cleaner.

Hopefully this should solve the rough idle! Maybe also worth having adaptations reset...

[GoRomeo]

I also agree with post above. Check your essentric valve sensor connector and look for oil inside the connector. If you see oil most likely is your sensor that needs replacement.

Defective essentric valve sensor may cause misfiring due to bad timing secquence. Its the seal around it that goes bad I ve read.

I dont have issues but planning to change my valve cover gasket soon. I will look for oil my my connector hopefully I dont see oil in it.

Keep us posted.

[narmon]

70k may be a little soon for your plugs but i'd double check them you never know. i've heard some people done the replacement at 70k and made a hell of a difference.

[Three_thirty_I]

According to my car's service schedule, spark plugs get changed every 100k km which is 60k Miles, so if the car is on 70k Miles and has the original spark plugs, then they are really overdue for replacement!

[Raptor3DPilot]

Thanks for all of the assistance and quick replies! I will definitely take a look at each item. I'm not going to be able to get around it til at least this weekend though due to my work schedule.

One thing to note, it's not exactly a "rough idle" as the title states. It's not constant, it's just as I am sitting at a stoplight with the car in gear, every minute or two it feels like the RPMs drop a bit and then rise up a bit. As stated, with the analog guage, I would guess 50rpms down and then 100-200 up. Those numbers could be off because the needle barely moves, but it can definitely be felt in the seats. That's why I feel it's a sensor compared to an actual failed part like a spark plug or something.

I will definitely clean the MAF as well. I haven't done it on any of my cars before, but I am sure I can find it somewhere on the internet.

Thanks again for all of the quick replies!

[Three_thirty_I]

Originally Posted by Raptor3DPilot

Thanks for all of the assistance and quick replies! I will definitely take a look at each item. I'm not going to be able to get around it til at least this weekend though due to my work schedule.

One thing to note, it's not exactly a "rough idle" as the title states. It's not constant, it's just as I am sitting at a stoplight with the car in gear, every minute or two it feels like the RPMs drop a bit and then rise up a bit. As stated, with the analog guage, I would guess 50rpms down and then 100-200 up. Those numbers could be off because the needle barely moves, but it can definitely be felt in the seats. That's why I feel it's a sensor compared to an actual failed part like a spark plug or something.

I will definitely clean the MAF as well. I haven't done it on any of my cars before, but I am sure I can find it somewhere on the internet.

Thanks again for all of the quick replies!

The symptoms can vary quite a bit for the different issues, in this case it could be something as simple as just a slightly dirty injector. So really a case of doing the easier and cheaper things first! Clean the MAF and run a tank of fuel with a good quality injector cleaner and see. With the eccentric shaft sensor issue, usually the idling is very rough with the revs jumping around quite a bit depending on how severe it has become.

[330iE90spt]

Originally Posted by Raptor3DPilot

Thanks for all of the assistance and quick replies! I will definitely take a look at each item. I'm not going to be able to get around it til at least this weekend though due to my work schedule.

One thing to note, it's not exactly a "rough idle" as the title states. It's not constant, it's just as I am sitting at a stoplight with the car in gear, every minute or two it feels like the RPMs drop a bit and then rise up a bit. As stated, with the analog guage, I would guess 50rpms down and then 100-200 up. Those numbers could be off because the needle barely moves, but it can definitely be felt in the seats. That's why I feel it's a sensor compared to an actual failed part like a spark plug or something.

I will definitely clean the MAF as well. I haven't done it on any of my cars before, but I am sure I can find it somewhere on the internet.

Thanks again for all of the quick replies!

Yeah, could be as simple of adding som Lucas Fuel System Treatment. From the sounds of it, that's the first thing I'd do!!

[GoRomeo]

I never tried LUCAS before, I ve only used Techron Gas treatment.

Anyone have tried both and noticed any differences?

[330iE90spt]

Originally Posted by GoRomeo

I never tried LUCAS before, I ve only used Techron Gas treatment.

Anyone have tried both and noticed any differences?

I haven't used it yet, waiting to use it with a full tank of gas.

http://www.e90post.com/forums/showthread.php?t=830024

http://www.e90post.com/forums/showthread.php?t=576621

[Three_thirty_I]

I used Liqui Moly Injector Cleaner for what it's worth. Pretty confident they all pretty much do the same thing.

[E90LA]

Originally Posted by Raptor3DPilot

As the title states, I have an 06 330i with 70k miles on it. I am at about 6500miles since my last oil change and am getting ready to do it this weekend.

On my last oil change, I had the P1554 (VANOS) code show up prior to the oil change. I removed both solenoids and cleaned them with carb cleaner and dried them out with compressed air. The P1554 codes never came back.

Now that I am near another oil change, I have noticed that my car is beginning to idle "rough" at times when the AC is on and at a stoplight (in gear). The RPMs will drop 50-100rpm and then increase 100-200rpm. It feels like the car is going to stall, but it hasn't yet. I've checked the codes using my code reader and everything comes up clear.

I've read that the rough idle could be an indicator of the VANOS solenoids. My question is, should I remove and re-clean the solenoids, or should I just replace them ($150 each)?

Any other thoughts on what could cause this? No issues are noticed while driving the car, only when it's at a stoplight, AC on, and in gear.

Thanks for any tips!!

I had the same issues and fixed it by replacing all 6 coils.

[VTECaddict]

Check the eccentric shaft sensor.

[Meeni]

it could also be a worn idler pulley on the accessory belt, since the issue relates to ac activity. it is also normal for idle to jump for 2 seconds when ac compressor turn on. if compressor cycles on off constantly it needs coolant fluid.