[The Maxican]

Hello everyone, on my daily, an e60 528i (N52), i started getting a rough idle along with a check engine light showing up. The CEL randomly turns on and off when the car sits and idles, but the rough idle stays fairly consistent. The idle while rough usually stays between 600-700 rpm, once the car is warmed up. The car drives fines, doesn't seem low on power, but i don't beat on it as its just a daily.

I pulled the codes with the Carly scanner and got:
002D06: Air Mass System
0029E0: Mixture Control
0029E1: Mixture Control 2

I was initially thinking of replacing the MAF sensor, but I'm not 100% sure, could it be a vacuum leak? Has anyone dealt with this before?

[iDab951]

Im having the same issue, but my problems started after I had a mechanic change my valve cover.. began running very rough and the mechanic claims it’s a bad ccv valve but my car shows no symptoms of it (no loud whistling sound, no strong suction from oil cap)
I cleaned the maf sensor that helped with the rough idling but the codes were still there, also changed spark plugs
I’m also assuming it could be either the vcg or valvetronic gasket weren’t set problem causing a vacuum leak
I noticed on the valvetronic gasket, he set it upside down it was also missing 3 fastners smh
Did your problems just start out of no where or were you making a repair?

[E92William]

Is your adapter able to show live data? Hope it is. You're gonna want to check what your short term fuel trims are at when the car is idling rough. Anything over 7 or under -7 is an issue to me.

Also you two could try unplugging the maf sensor when it's doing that and see if it changes anything or maybe swap it with a known working used one.

If the fuel trims are all over the place you might wanna do a smoke test to isolate the problem.

[The Maxican]

Originally Posted by iDab951

Im having the same issue, but my problems started after I had a mechanic change my valve cover.. began running very rough and the mechanic claims it’s a bad ccv valve but my car shows no symptoms of it (no loud whistling sound, no strong suction from oil cap)
I cleaned the maf sensor that helped with the rough idling but the codes were still there, also changed spark plugs
I’m also assuming it could be either the vcg or valvetronic gasket weren’t set problem causing a vacuum leak
I noticed on the valvetronic gasket, he set it upside down it was also missing 3 fastners smh
Did your problems just start out of no where or were you making a repair?

So i changed the valvecover gasket a few months ago, while it was apart i changed the valvetronic gasket, the crankcase vent hose, and the spark plugs. Car ran fine for about a month, idle was slightly rough but it was hardly noticeable, figured it was just the AZ heat getting to the car combined with constantly running the AC on max. Then replaced the crankshaft position sensor about a week and a half ago after it went bad. The really rough idle happened after i put it back together. I cleaned the MAF and it didn't change anything, so I'm thinking the MAF isn't the problem.

Originally Posted by E92William

Is your adapter able to show live data? Hope it is. You're gonna want to check what your short term fuel trims are at when the car is idling rough. Anything over 7 or under -7 is an issue to me.

Also you two could try unplugging the maf sensor when it's doing that and see if it changes anything or maybe swap it with a known working used one.

If the fuel trims are all over the place you might wanna do a smoke test to isolate the problem.

I cleaned the MAF and it didn't change anything, I'll try unplugging it and seeing what happens. I'm not sure if Carly shows live data, I'll have to plug it in and see. After doing some research, I'm leaning towards vacuum leak as of now, gonna perform a smoke test in the next few days and see what happens.

[bluewater328]

+1 on unplugging the MAF.

[HydroxFrost]

Its more likely a vacuum leak than a MAF problem but it is possible. Unplugging the MAF allows it to ignore the vacuum leak but its worth taking an overall look at your intake boot, valve cover gasket, pcv, and vacuum lines.