no power when accelerating
 

hey guys so I'm away on business and I drove her for over 2 hrs with no problem. I was an hour early so I just sat in it for 45 mins with it running and then decided to hit a gas station real quick. she had no power meaning acted like it was a small 4 banger instead of a 4.4 v8. the fan is really loud seemingly audible based on rpm level. no over heating, no smoke, no smell, no obd2 codes, no check engine light, no creamy color in oil, oil level coolant level and transmission fluids all check good. no leaks that i can tell, idles fine, transmission shifts at correct rpm and smoothly, once at desired speed the fan gets quieter and she rides normal. JUST NO POWER! tomorrow a coworker is going to stop by the hotel and scan it with his bmw software. I'm not sure what version or program he is using. Please help!

oh and it is a 2000 4.4 sport package now at 101k. relatively recent work done includes new spark plugs, new valve cover gaskets, both rear air bags on suspension, new tires, laser alignment.

when you say no power, what do you mean? you say the idle is normal, shifting is normal, no codes, no external symptoms... what makes you feel that the power is lost?

you press on the pedal, does the engine react? the RPMs go up with the pedal? or, you floor it, but the RPMs are barely going up to 1500-2000? could it be the air supply is compromized? check the MAF, the air hoses, the throttle butterfly...

how about a vacuum leak? when you pop the hood, any strange noises?

no strange noises. no power meaning it reacts like a slow hybrid, rpm climbs but forward movement and rpm are not matched as normal acceleration for it. it's about half of regular performance. i put it in neutral and floored it the fan was so loud it sounded like a tornado and rpm increase wasn't quite as fast. sorry it is hard to describe other than saying half performance and extremely loud fan when increasing rpm level.

Hopefully there will be some codes to help pinpoint the problem. Sounds like everything was fine and all of a sudden it isn't? Terminator has asked the key question without a scan, how the engine reacts to peddle pressure both driving and in neutral? I have seen your symptoms when a cat crashed and that happens without any warning. If it started directly after taking on fuel, was it from a 1st. rate name brand source?

I actually didn't put any fuel in. after noticing the problem I drove drove it for a few miles and returned to work. thanks for helping guys. and yes everything was fine before the 45 idle in the parking lot. the car was never turned off.

My experience with MAF going bad was that it first caused a rough idle, it gave you warning. That said, to test the MAF, unplug the connection. If the condition improves or disappears the MAF is the culprit. I can't think of air blockage that would come on that fast, or spark. I suppose fuel could but not likely in your case unless you were sucking the tank dry. The long idle time has me leaning toward a cat or something in the emission system but I would think it would light up the dash with warning.

fuel lines clogged? fuel filter?

how about taking a short video for us?

pulled the maf, problem still persists. tomorrow I might be able to snag a quick video on my way to work. I'm trying not to drive it but tomorrow I have to drive it to work so that I end up within a hundred miles of home so AAA will tow it.

check engine light just came on. probably because I pulled the MAF. two videos. the first is in neutral the second in drive.

In neutral - YouTube

In drive - YouTube

yes I know my brakes are squeezing...

it seems that the engine responded fine while in neutral... but when i gear - the RPMs went high, the speed did not... wonder if it has to do with the tranny???