Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hey what's guys? Man the cars I'm getting are really kicking my butt. 07 bmw comes in running good and then all of a sudden it starts running rough like an air leak and the engine is shaking. Has lean codes for both banks multiple misfire. I'm checking for air leaks and nothing. This is really weird. Every week I run into different issues that I really can't put my finger on it. Gotta get a bmw book and read about these systems. Any suggestions guys. Car came late in the day and I said I need to do research and leave it for tomorrow.
Jay2034 wrote: Thank u brother but What do u mean maf good idle tap?
I think he means, while watching scan data (lean/rich fuel trims) tap on the MAF and see if the fuel trims start coming back to normal. If so, need to clean the MAF, check the wiring or clean the MAF. Hope this helps.
The car is running good when you start and then cames the problem, isn t?
So when is running ok, if you tap the MAF and it get bad idling again it means the culprit is MAF!!!
derekoliveira wrote: The car is running good when you start and then cames the problem, isn t?
So when is running ok, if you tap the MAF and it get bad idling again it means the culprit is MAF!!!
Looking at your scan data, when both banks are running lean (running bad) tap on the MAF and look at your codes (also the car may start running better). If they start to return to normal, then it's probably the MAF.
That is certainly a good test to do. You can also inspect the MAF to see how dirty it is. I'm not sure that your problem is going to be the MAF however. It sounds like you have a huge vacuum leak somewhere. Have you checked to see how much fuel pressure you have? I've had that bite me a few time as well.
Ok I got it now. It just sounded like a bi directional test or something. Lol. But will do when the car comes back. I just ordered bmw books from atg because I want to know about these cars and help other just like u guys are doing for me. Will keep u guys posted when the car comes back. Btw I wasent checking the car it was some other new supposedly tech who does engine diagnostics and he was stumped so the boss called me to help and I'm like hold up didn't this guy say he does engine diag work. So I wasent looking at the scan data...he was and I was telling him what are u seeing and testing his knowledge and clearly he didn't know what he was doing so I looked at it to see if any visible vacuum leaks and found nothing and told the boss u guys hired him because he said he knows engine diagnostics so let him figure it out. They respected it and since he couldn't figure it out they sent it and hopefully it does come back but when it does I will be prepared. Hope u guys understand.
Hey Derek yeah when the car comes back I will attack it in a way that u guys are helping me. The way this car was chugging I don't know if I should test drive it at wide open throttle to see the 02 sensors if they go full rich or stay lean. That's what u are referring too right derik?
But for sure Derek i will take ur advice and do the tap test on the maf and see if that changes or take it out and clean it. But for real when I looked at it for a bit and was touching the air book and sticking my hand under where the iac is at and tugging on those hoses I felt nothing loose. But it did feel like a big vacuum leak to me at least Derek. But like I said I left it alone because that guy is supposedly this super tech that was checking it out who clearly looked like he didn't know how what he was doing. I just want the bosses to see who they just hired and to test him. But when or if it comes back I will take all u guys advices and I greatly appreciate it. Again this forum is the best. And when that bmw book does come will share stuff with u guys. God bless stay in touch
Maybe you found out the culprit?! When i say PID data is stft and long tft if you know what i am talking about? I don t know is am rithing the right way but if you watch Paul Danner video about fuel trims/vacum leaks diagnosis, you will understend what he is talking about!!!
Yeah that's exactly what I did and it was a big vacuum leak. The ccv valve was stuck wide opened. I got a bmw book and it directed me to that valve. The way it directed me was to remove the oil cap slowly and if it sucks it down then the ccv valve is the culprit creating the vacuum leak and setting the misfire codes as well. So guys just be on the look out if u got one of these bmw with vacuum leaks and misfire codes. It's a pain in the neck to get too but just have patience and it will be done. Thanks again to everybody who lended out a hand in trying to figure this out.
