Ok so I'm the rookie owner of a 740i Sport. I am still trying to track down the noise under the hood but now I have a nother experience to relate and hopefully get some help or advice. I needed some of that famous BMW acceleration the other day so floored it. The result was the car, of course, took off, but then it began to sputter and the "Engine Fail Safe Mode" read out appeared. The car seemed to be running on like two cylinders. I pulled over turned the engine off and researched the problem in the owners manual. OK so now I now what that means. "The Service Engine Soon" light remains on so I am planning to do just that. But the problem is that now the car seems to run fine but on occasion it will quietly die. As if it can't maintain idle. It is not a regular occurence but it can be annoying. I am going to schedule a full 150,000 service inspection. What do you think the problem is and what should I learn from the 150K inspection? Thanks fellow Bimmer owners.

Could be a plethora of problems... not to sound dark and daunting. To cause that type of failure you might have lost vacuum pressure (does it idle rough or spew smoke at startup?), the mass airflow sensor is shot, the throttle body is pooped, the ECU could have crapped out, your O2 sensors, knock sensors or crank position sensors may have given out. It is possible you have air in your cooling system, your fuel injectors gave away or the fuel pump is shot.

Those are the things I would look at first. I would also check spark plugs and wires too for good measure.


Good luck and report back to us when the inspection is done. I wouldn't drive the car until you get it inspected and I would tow it to the shop!

Thanks Greene08; Seeing as how we have identical cars that means a lot but my car has none of those symptons. It seems to running fine and idling just fine. I did some research and found another 740il owner with an identical problem and it was the oxygen sensor. I am going to have mine looked at ASAP. Will this do any serious damage to the engine or catalytice converter?Tell me what other problems should I be on the look out for? Thanks Greene Guy!!!

I bet you snaped a lead on the MAF. If it wont idle its earither not getting enough air or fuel. Id bet fuel is fine and it's the flow air. Pull the maf and look inside. You will see a bunch of small wires. Make sure they are all still connected. Also, check all the spark plug caps. You might have lost fire in one. Can you get it to an Auto Zone to read the ODBII code?

A little something I forgot to add to the equation. I had just completed an oil change about hour or two previous to this event.

The oil change should not result in your symptoms, but who knows. I would run your car through a OBD scanner to see what codes come up. I would vote O2 sensor or MAF sensor has gone bad. I would not drive the car if you can avoid it in the meantime as you can hurt your cats if fuel is not buring properly. You shouldn't damage any other component of the car, but be cautious and get it looked at ASAP.

Ok so I'm the rookie owner of a 740i Sport. I am still trying to track down the noise under the hood but now I have a nother experience to relate and hopefully get some help or advice. I needed some of that famous BMW acceleration the other day so floored it. The result was the car, of course, took off, but then it began to sputter and the "Engine Fail Safe Mode" read out appeared. The car seemed to be running on like two cylinders. I pulled over turned the engine off and researched the problem in the owners manual. OK so now I now what that means. "The Service Engine Soon" light remains on so I am planning to do just that. But the problem is that now the car seems to run fine but on occasion it will quietly die. As if it can't maintain idle. It is not a regular occurence but it can be annoying. I am going to schedule a full 150,000 service inspection. What do you think the problem is and what should I learn from the 150K inspection? Thanks fellow Bimmer owners.

I second Green08's advice. Get it towed to a reputable repair shop or $tealer and avoid driving it. The bottom line....Get that code read because until that is done all you will be doing is just guessing at what the problem could be. Good luck to you.

OK I got the OBDII diagnostic done and it read P0102. That equates to Mass or Volume Air Flow Circuit Low Input. How troublesome is the situation and can DIY the problem. Anyone?

Mine did it not too long ago, nailed gas, wouldn't downshift, engine failsafe, stalled...restarted - and then it eventually started to die coming to a stop or wouldn't idle unless I held the throttle a little.

Mine was the MAF - don't go to BMW for the part - go to your local Range dealer - the link is on e38.org - it's the EXACT part for $135.00 vs. the $350 at your bimmer dealer.

All you need is a screwdriver, it pops out, and new one pops right in. I did it in the lot at the Range dealer as I took in the old part and compared... easy fix.

All you need is a screwdriver, it pops out, and new one pops right in. I did it in the lot at the Range dealer as I took in the old part and compared... easy fix.

+1

I actually had my 2-year-old change out my MAF for me.

And 4point4 is right, all he used was a scrwew dwivow.