[Roowah]

While driving today, my Service Engine Soon light came on with no other error lights. Now of course, my BMW extended warranty expired at the end of last month, and I'm not sure who to take it to.

I think I noticed that when cold, I would feel a little "catch" in the idle. Although later I didn't notice any rough idling. After doing a search, it could be anything from a loose gas cap (I did put gas in yesterday, but the cap is tight) to possibly ignition coils. If it helps, I did have a new engine air filter installed about a week ago. I won't know for sure what the true issue is until it's looked at.

So the dilemma is that I'm not sure who to take this problem to. Do I bring it to the dealership that I had a good relationship with while under warranty, or an independent shop where I've had some recent small services done (Bavarian Performance Group in Winchester, MA) to have it diagnosed? The reason I'm considering the dealership is MAYBE they will give me some good will service being the warranty ran out last month, and maybe it's not an expensive repair. Basically I don't want to pay for diagnostics from one place then take it to another for the service.

Any ideas and approximate costs? I had my car thoroughly looked at last month before the extended warranty expired and it checked out perfectly. I currently have just over 43,000 miles.

[John 070]

I would try the dealership you had the good relationship with. For example, when a dealer fixes your brakes under warranty, that's good will, not BMW. So it's worth a shot.

Sorry to hear your extended warranty just expired--I added a 7/100, and have used up 1/2 of it, NOT ONE SINGLE ISSUE. I can imagine the same thing happening to me....

[Cisco661]

sounds like it just needs some kind of servicing done. if you have i drive scroll through and find which one it is. i think you can also look through the dash using the bc stalk. its probably just that you need to change something like cabin airfilter, brakes, oil change, or something. if you wanna be for sure i would just take it to an indy and have it scanned to see if its something mechanical. if you feel bad idling it could be an ignition coil. you said you changed the air filter. check and make sure that you connected the MAF sensor properly and that its secure. since your out of warranty i would recommend that you invest in something like a bavtech scantool to scan for codes when these issues arise. at least that way you can go into a shop knowing what your in for. good luck. keep this thread updated. i too have a 330i and would like to know what happens in case i have same issue.

[Roowah]

Thanks for the replies so far!

Originally Posted by John 070

I would try the dealership you had the good relationship with. For example, when a dealer fixes your brakes under warranty, that's good will, not BMW. So it's worth a shot.

Sorry to hear your extended warranty just expired--I added a 7/100, and have used up 1/2 of it, NOT ONE SINGLE ISSUE. I can imagine the same thing happening to me....

There's definitely a part of me that is leaning that way. Plus, they have a 15% coupon for any repairs, so that might help balance the costs between the dealership and the indy shop.

Originally Posted by Cisco661

sounds like it just needs some kind of servicing done. if you have i drive scroll through and find which one it is. i think you can also look through the dash using the bc stalk. its probably just that you need to change something like cabin airfilter, brakes, oil change, or something. if you wanna be for sure i would just take it to an indy and have it scanned to see if its something mechanical. if you feel bad idling it could be an ignition coil. you said you changed the air filter. check and make sure that you connected the MAF sensor properly and that its secure. since your out of warranty i would recommend that you invest in something like a bavtech scantool to scan for codes when these issues arise. at least that way you can go into a shop knowing what your in for. good luck. keep this thread updated. i too have a 330i and would like to know what happens in case i have same issue.

I don't have I-drive, but I don't think it's a service needed issue. When I do a stalk service check, everything is fine. The MAF sensor seems interesting. I had the indy shop change my oil and engine filter about a week ago. Do they need to disconnect the sensor when changing the engine (not micro) filter? Could a improperly connected MAF sensor create a slight rough idling and Service Engine Soon light?

[Cisco661]

if they changed the air filter in the air box, then yes the MAF sensor need to be disconnected. it could just be that it needs to be cleaned. it just clips on and off. they sell MAF sensor cleaner at any aut parts store. hopefully you can get more responses beacuse it could be another issue. still i wouldnt drive around too much and risk possible damage.

[djjasper]

An SES light on means it has an error code stored. Autozone, advance auto parts, pep boys etc will all do a free scan for you to help narrow it down if you think your dealer will charge you $130 or whatever just for diagnosis. A scan at the auto parts place will be pretty vague but will give you the error code you can research and will point out if it is a misfire on a particular cylinder.

[Roowah]

Originally Posted by Cisco661

if they changed the air filter in the air box, then yes the MAF sensor need to be disconnected. it could just be that it needs to be cleaned. it just clips on and off. they sell MAF sensor cleaner at any aut parts store. hopefully you can get more responses beacuse it could be another issue. still i wouldnt drive around too much and risk possible damage.

Originally Posted by djjasper

An SES light on means it has an error code stored. Autozone, advance auto parts, pep boys etc will all do a free scan for you to help narrow it down if you think your dealer will charge you $130 or whatever just for diagnosis. A scan at the auto parts place will be pretty vague but will give you the error code you can research and will point out if it is a misfire on a particular cylinder.

Again, thanks for the replies!

I'm encouraged that the MAF sensor may be this is the issue. Since they did change the air filter, it could be possible that the sensor wasn't reinstalled securely. I'll try to bring it over to them tomorrow and see what they say. If that's not it, I may have them do a scan for an error code. There's a possibility that since I'm bringing it over to them, that they may scan it anyway to see if that's the problem. Would a disconnected or loosely connected MAF sensor cause an intermittent stuttering idle as well?

Unfortunately, I wish I had time to go to an Autozone for a scan, but my work schedule will prevent me from doing so. That's exactly the reason for my dilemma....which repair facility would be the best, and possibly most cost effective place to take it.

[Cisco661]

hope all goes well Roo. update the thread. i wanna know what it is.

[Roowah]

I've set an appointment for tomorrow with the indy shop that installed the engine air filter after explaining the thoughts about the MAF sensor. They're going to check it out and I'll keep you all posted.

By the way, is there a way to check myself if the MAF sensor is loose or disconnected? Where is it located on my vehicle?

[Cisco661]

yea very easy. its the only electrical piece hooked up to your airbox. its like a small plug type with wires coming out of it. just give it a look to see if its dirty, broken, loose, or anything wrong. let indy know that you didnt have the issue until you took it to them and if they could make sure that they followed are correct steps to hook things back up. if you still cant locate it update the thread and ill get you a pic.

[Cisco661]

here hopefully this helps.

[Efthreeoh]

It's probably not the MAF. If you had the airfilter changed and the MAF was not reconnected properly it would have thrown a fault code right away. The emissions systems cannot operate properly without the MAF connected. Service Engine Soon codes are OBDII codes. Some OBDII codes come on once the car performs periodic self-checks and finds a problem (such as bad cats), other codes come on immediately, like when the MAF is disconnected. If the code didn't appear right away then the MAF was connected when they reinstalled the air box. If the MAF was connected, I doubt the connector was improperly inserted into the female end making a temporary connection that came loose; it is a very tight and waterproof sealed connector.

I'd bet it's one of the VANOS solenoids are dirty and need cleaning. There is a good DIY in the DIY section on the VANOS solenoids. Go read up on it so when you take it somewhere you'll understand what they are talking about.

If it is a bad coil, then the engine would be running terribly all the time. Or it could have been a simple mis-fire that has cleared itself.

You got good advice. Get the car scanned for free first. Have them give you the OBDII code(s) (write it down) and look it up on line. Go read up on OBD II also. Understanding the OBD II system is very important for owners of cars from the model year 1996 onward.


Good luck.

[Roowah]

Cisco661, thanks for the pictures. I checked that connector, and it is definitely connected tightly.

Efthreeoh, that's interesting regarding the VANOS solenoid. Is this something that's a common issue? What would cause it to become dirty and throw a code? Also, is cleaning the solenoid the common practice, or do they typically replace it? Would there have been symptoms prior to the SES light turning on that I should've noticed?

I've scheduled an appointment with the dealership, as I have a very good relationship with them. Since I'm just out of warranty, I'm hoping for some type of good will consideration. If not, any idea of the cost to repair if it is that problem? The earliest appointment they have available is not until July 9th, if I want to meet with my SA (I definitely do), and have a loaner vehicle available (I do). She said that driving it until that time should not cause any damage with that type of warning light. Fortunately, I have no long trip plans before then.

[Roowah]

So for the people that were interested in keeping updated, I brought my car into the dealership today, and they diagnosed it as the bank 2 pre cat O2 sensor. I asked about the vanos solenoid, and they said it seems to be fine at this time with no error codes.

Could a faulty O2 sensor cause a rough idle on start up?

[bumere90]

I have a bmw scanner
Let me know if you want it
Very cheap

[JuppiOne]

Originally Posted by Roowah

So for the people that were interested in keeping updated, I brought my car into the dealership today, and they diagnosed it as the bank 2 pre cat O2 sensor. I asked about the vanos solenoid, and they said it seems to be fine at this time with no error codes.

Could a faulty O2 sensor cause a rough idle on start up?

very likely, if there is no reading from the sensor or reading out of range (due to a bad sensor), CPU will use default setting, which could cause rough idle, among other things, since there the o2 reading is not available

[Roowah]

Originally Posted by JuppiOne

very likely, if there is no reading from the sensor or reading out of range (due to a bad sensor), CPU will use default setting, which could cause rough idle, among other things, since there the o2 reading is not available

Looks like you're right. There have been no issues with a rough idle since they replaced the O2 sensor. I'm glad I went to the dealer for this. I had the codes read at a indy BMW shop near me, and they said it was both the O2 and one of the vanos solenoids. It would've cost me about twice as much if I let them do the repair!

[wickedfrog86]

Originally Posted by Roowah

Looks like you're right. There have been no issues with a rough idle since they replaced the O2 sensor. I'm glad I went to the dealer for this. I had the codes read at a indy BMW shop near me, and they said it was both the O2 and one of the vanos solenoids. It would've cost me about twice as much if I let them do the repair!

the same thing just happened to me today! i had the regularly scheduled service completed on my car yesterday by BMW in which they changed the air filter, among other things, and driving home today the SES light came on. my warranty expires today but thankfully they put in the paperwork for the car today and asked me to bring it by first thing tomorrow. i actually had a rough idle some time back and the car completely shut off on me with a check engine symbol in the info screen but bmw said it was just a hiccup (i thought the excellent bmw engineering was supposed to eliminate these "hiccups" lol). hoping its an easy fix like yours.

[Roowah]

Originally Posted by wickedfrog86

the same thing just happened to me today! i had the regularly scheduled service completed on my car yesterday by BMW in which they changed the air filter, among other things, and driving home today the SES light came on. my warranty expires today but thankfully they put in the paperwork for the car today and asked me to bring it by first thing tomorrow. i actually had a rough idle some time back and the car completely shut off on me with a check engine symbol in the info screen but bmw said it was just a hiccup (i thought the excellent bmw engineering was supposed to eliminate these "hiccups" lol). hoping its an easy fix like yours.

Glad that you were able to bring it in right before your warranty expired! I'm sure it must've been a coincidence that it happened for both of us after the air filter was changed. After the warranty, it was an easy, but not inexpensive fix. Fortunately, it still looks like it worked!