So minus the transfer case scare back last week which doesn't seem to have come from anywhere, got it up in the air and could not spot a leak or trace of oil/ATF, must have been from the Wife's CRV which has been parked and moved around occasionally due to being on it's last leg. Thank goodness.
Get the computer hooked up to it... (Just an OBD reader, not INPA mainly because I don't know where to buy it) and I have codes galore.
I'd start with a smoke test. If no vacuum leaks... move onto the o2 sensors... and then finally check the catalysts. How many miles on this X5?
I hade 80% of the same codes on a 2001 I just bought and it was the fuel filter.
Probably on to something there... for starters... I know I have the smaller bellows hose on the intake boot patched up with some gasket sealer... might have finally came loose. It was shredded when I got it. Sealed it when I bought the car since I read horror stories on here about purchasing non OEM and didn't have the extra to toss it at the time.
Had to take off the intake to replace the whole CCV system and went ahead and replaced all the seals and vacuum lines in a shotgun restoration to eliminate any potential problems down the road. So more than likely that intake boot since it is after the MAF and had to be removed while in such a delicate state.
Planning to do a smoke test on it tomorrow, just didn't have time to get down to the shop today.
As of this afternoon she's got 253,369 Miles.
Mystery Service History -- With one BMW service record from 2011 at 118k miles where they replaced the water pump and recommended the VCG be replaced due to some oil in the spark plug wells, but the owner declined on the latter. Needless to say I ended up replacing this myself a few months ago... along with pretty much any DIY you can find on this E53 Forum, short of the Oil Pan Gasket... which I am dreading if I ever have to do.
You know I ran some UV dye through the gas tank when I first got it... kept dying on me with 1/4 tank left and missing like crazy when below half a tank... turned out to be the fuel siphon jet o-ring... which AndrewWrynn had an awesome DIY that saved me there... but I was worried the bottles of UV dye I put into the tank might have done the fuel filter in. After the o-ring was replaced everything ran like clockwork. That being said I am pretty sure it's the factory fuel filter from the date stamp of 02/00 on it.... So very well could be on the table as well.
Great suggestions guys, thank you for your time.
Will post updates tomorrow afternoon.
If you get a dip in pressure that recovers under WOT (wide open throttle) i would suspect the FPR but if the pressure stays a little low under WOT I would suspect the electric pump.
I had a BMW Fuel Pump put on it right when I bought it in pursuit of the fuel issue that your Siphon Jet O-Ring DIY fixed for me. Is this the pump you're talking about? Or is there another one? I can't say for sure if it cleared up under WOT, wife pulled it over and shut it off and let it sit for a few minutes then nursed it home.
Yes that's the fuel pump. Now in my case I can swap with wife's car virtually any part to root through problems.
I would get a fuel pressure gauge and measure under load and verify if you are getting constant pressure or not.
I had a fuel pump fail after ten months so anything is possible but I'd proceed with knowledge. With a new fuel pump if pressure isn't maintained then it's likely the FPR had failed.
I can see where it might have died already. Thankfully that BMW has a warranty on their parts... otherwise I would have went cheaper.
Though the darnedest thing happened this morning. I expected to fight it it on the way to a meeting a few miles down the road... but after clearing the codes and letting it sit over night, it drove like a new vehicle. Which makes me lean toward that vacuum leak... not sure if it will happen at warm / hot again but running cold... perfect.
Vacuum leak won't cause a meltdown in performance. You'll get codes warning you you are getting bad efficiency.
If you get enough misfires in a particular cylinder, the brain will shut off that cylinder and your performance will go to hell instantly and typically stay that way until you clear the codes.
Try some full throttle acceleration runs and see if you get a misfire code. When this happened to wife's X5 last year it turned out to be bad plugs. It got so bad at the end she could only drive about 6 miles before having to pull over and reset the codes.
I would buy/rent a fuel pressure gauge and see if you are losing pressure at high Fuel demand, also if you get the errors on one or two cylinders, swap some coils and plugs so see if the problem moves.
It's Bucking like an ISUZU Rodeo sold by Joe Isuzu because you have misfires with fuel cutoff. Shutting and restarting the engine does it run better? If it does you need to find out why you have the misfires.
The cat efficiency could be your Cat is going south and I don't mean Florida.