Loss of power
 

Just had my x5 on a dyno today.

189 hp 326.4nm

What the hell?

It has new catalysts with new o2 sensors.
New Air flow meter.
New filters, Oil and Air.
fresh oil.

No Error codes.

What could be causing this lack of power?

It is a 4.4 M62

Have you ever changed your fuel filter? Spark plugs? Not that it would make a huge difference/change but it might help somewhat. What year is your X, I dont remember what the hp figure is for a 4.4M62.

Its a 9/2000
Haven't changed fuel filter, will do.
Spark plugs i will check after work. although just replaced.

Normal figures is 286hp and 440nm (Factory)
Would be satisfied with 260 hp but right now i'm no way near close to that.

You do realize that there is a drivetrain loss somewhere between 20/25% which puts your HP figures 230/215HP. I am not sure if the dyno you used has to do with anything. So if there is a 25% drivetrain loss your at about 215HP which is close also depends on the milage on your engine.

Yeah, as mentioned above the stock HP numbers are at the flywheel and you are going through the whole drivetrain. If your transmission isn't holding up its end of the bargain it can cause the numbers to be lower than normal.

I know there is loss in the drivetrain and dyno but we have tested another car exactly the same as mine, 5 minutes later. and it popped out with around 240hp so if only i can get mine up to that i would be pleased.

But mine has an extensive dive at 5000 rpm. and then it picks up power again. (drops 25KW)

I will tomorrow try to change fuel filter and sparkplugs.
Then run it again on dyno to see if it helps.

Mileage on the 2 cars differs appx. 1000 miles.

UPDATE!
Ok, changed spark plugs yesterday.

Cursed a lot. there is absolute no room for any tools on the drivers side cylinders towards the firewall.

The plugs were missing the center electrode, on all of them. Guess they needed a change.

Now the car is pulling fairly, although i still get a small "delay" in power when exceeding 120 mph. (of course this is tested on a closed circuit ;-) )
Today i will try to change fuel filter as well.
Tomorrow my new setup of EBC brakes will arrive so that i can stop again.

What do you mean by they were missing the center electrode? If I recall correctly the center electrode does not rise very high from the insulator. Thus what you describe is likely to be normal.

the center electrode, was below the ceramics. that's how worn they were.

I know how these are supposed to look, but they were very low.
unfortunately i did not take any pics.

But a change of plugs has really changed the way the motor responds.
Much quicker pickup of revs, and more bottom torque.
I do believe that when i change the fuel filter, it will again be almost as fresh as new.

This is just incredible, the car has a full service book. Always performed at BMW but even the oil filter was the original from new. date stamp was the same as production month. I could litterally see through the filter. Big holes everywhere.