2001 528i. running lean

Error code says that both front banks are running lean. What is the first thing I should do?

Originally Posted by putitupmike

Error code says that both front banks are running lean. What is the first thing I should do?

Vacuum leak.
second is vacuum leak.
And the third thing to check is...you've already know.

2001 528i?? does that exist?

Fourth thing is vacuum leak ...
Fifth is vacuum leak ...
And, sixth ... is ... umm ... look here.
- How to diagnose a BMW E39 engine misfire (1)

Originally Posted by putitupmike

Error code says that both front banks are running lean. What is the first thing I should do?

There's no "both front". If just one bank then maybe not vac leak. If both then still maybe not vac, could be maf needs crc cleaner. Also check fuel trims real time, see if lean at say 3k rpm, if so then maybe not vac but fuel flow.

Follow up. Sounds like my 525i... has a vacuum leak. At least that's where I will start. I hope cleaning it will be good enough as they are $250, and frankly I would rather just pay my kids rent. Mike, regarding your cars look, I think the red rims look great and especially when seen from the rear and you get some taillight in the photo. Anyway I will Google cleaning a MAF and get to work on it. Wish me luck, cuz lean or not... it''s just purring.

Hi.

Any progress on this im about to replace my MAF but can't find any part number printed on it.

I dont think i have an airleak because i hear no noise when i take the oilcap of on idling or when i remove the dipstick.
Whats strange is that there is no difference in idle when disconnecting the MAF.


I will order a new one as soon as i can find a part number printed on it, its not printed on the top.

Mine looks like this but nothing is printed on it.
http://www.maf-shop.com/en/vdo-sieme...766a940685f8ae

Where do i find the partnumber on my MAF?

^RealOEM.com

Sound like you need a new MAF if it makes no different when it's disconnected.

Originally Posted by putitupmike

Follow up. Sounds like my 525i... has a vacuum leak. At least that's where I will start. I hope cleaning it will be good enough as they are $250, and frankly I would rather just pay my kids rent. M Anyway I will Google cleaning a MAF and get to work on it. Wish me luck, cuz lean or not... it''s just purring.

if you suspect that you have an air leak, how does cleaning the MAF seal off the leak?

aren't u better off looking for a leak, like in between the accordion folds of the intake boot, per se?

Too cut to the short and sweet--check out the following--if you can DIY you can have ago and spot the area's that can cause your problems
http://www.bimmerfest.com/forums/sho...eaks+revisited