need help with 2000 X5 I just purchased.

I just purchased a 2000 X5 for a really good price because it has issues.

I changed the water pump.

It was throwing the codes P1421, P0300 & P0306

So I changed all of the spark plugs and the iginition coil for cylinder #6. The old spark plus had carbon build-up but nothing bad and no signs of oil on them.

I cleared the codes and I'm currently waiting for the CEL to come bacl on so I can see what codes are still there.

The X5 still idles rough, but once I put in in drive and start driving, it drives like a dream until you stop at a light and it rough idles again. It's not about to shut off but a rough idle.

When the car is cold, there is a loud ping/clank sound coming from the left rear of the engine. almost as though you are hitting a wrench against metal. It happens once every 10 to 15 seconds and then goes away after the engine warms up.

Would you guys suspect that there are more bad ignition coils or something else?

In the first picture there I circled a hard plastic hose that I have no idea what it plugs into. Any clues?

In the second picture, the x5 came without the 'false firewall' that seperates the engine compartment from the fresh air vents area. it was also missing the plastic piece that goes on top of that. Does anyone know the part numbers for those.

I'm now pulling: p0300, p0305, p0306, p0307, p0308

This morning (before heading off to work), I tried two tests to see if I could determine what was causing my multiple misfire codes for only one side of the engine.

1st) I took out the O2 sensor (before the catalytic convertor) and drove it without the O2 sensor to see if the catalytic convertor was bad. The X5 was still running rough and throwing the same codes. This must mean the catalytic convertor is working. if the rough idling issue had stopped, that would of meant the catalytic convertor was clogged and bad.

2nd) after putting the O2 sensor back in, I started the X5 and while it was running I removed the plug from each ignition coil (one at a time), to see if the idling of the engine would change. The engine idle didn't change. I believe the idle should of changed if the ignition coils were firing. So that must mean the coils are not firing as the codes suggest.

Tonight I will remove each ignition coil (one at a time) and the corresponding spark plug, keep the ignition coil connected to the power plug and have the spark plug connected to it as well. I will then have someone turn the igition on as I hold the threading part of the spark plug next to a good ground (-) on the car with the expected results being my ability to see the spark generate on the spark plug. If I don't see a spark, that would mean there is no fire going to the spark plug, which MAY mean the iginition coil isn't working.

Any advice?

One last thing, I sprayed my MAF sensor with MAF sensor cleaner and now it doesn't work. So now I have to order a new one.

Originally Posted by Mrathell

This morning (before heading off to work), I tried two tests to see if I could determine what was causing my multiple misfire codes for only one side of the engine.

1st) I took out the O2 sensor (before the catalytic convertor) and drove it without the O2 sensor to see if the catalytic convertor was bad. The X5 was still running rough and throwing the same codes. This must mean the catalytic convertor is working. if the rough idling issue had stopped, that would of meant the catalytic convertor was clogged and bad.

2nd) after putting the O2 sensor back in, I started the X5 and while it was running I removed the plug from each ignition coil (one at a time), to see if the idling of the engine would change. The engine idle didn't change. I believe the idle should of changed if the ignition coils were firing. So that must mean the coils are not firing as the codes suggest.

Tonight I will remove each ignition coil (one at a time) and the corresponding spark plug, keep the ignition coil connected to the power plug and have the spark plug connected to it as well. I will then have someone turn the igition on as I hold the threading part of the spark plug next to a good ground (-) on the car with the expected results being my ability to see the spark generate on the spark plug. If I don't see a spark, that would mean there is no fire going to the spark plug, which MAY mean the iginition coil isn't working.

Any advice?

One last thing, I sprayed my MAF sensor with MAF sensor cleaner and now it doesn't work. So now I have to order a new one.

Just throwing something out there as I don't have the time to look up the codes: try checking the Oil Separator hoses. Do a search on them under my handle as I wrote about them extensively.

Thank you sunny5280, I'll check into that.

Today my mass air flow sensor arrived. I connected it and for 60 glorious seconds it ran absolutely beautiful. After the engine warmed up and the idle dropped, it started running rough again.

I'm still getting the same codes for misfiring on cylinders 5, 6, 7 and 8 (driver side of the engine).

I took it out for a ride and the same as before, the moment you hit the gas, the engine smooths out and rides like a dream.

I was wondering if the MAF sensor worked for the first 60 seconds and then stopped for some reason.

While it was running, I put my hands by the exhaust. The passenger side exhaust air was hot as expected but the driver side exhaust air was cold. I think one of the reasons that is weird because the left and right pipes from the engine becomes one half way under the car and then it splits back into two exhaust pipes. When the pipes merge together as one, I'm assuming the exhaust gas exiting both exhaust pipes is a mixture of exhaust from the lest and right side of the engine, so the exhaust gas should of been hot from both pipes. Am I correct in my assumption?

I pulled the following data from the dash area when you hold down the right button and the TEST NR1 displays, Im not sure if it means anything:

FGSTNR DN73411
K 7356
BMWTNR 6906996
CI 12. DI 08. EI 11
DAT 28101
HW 16. SW 1400/1400
ZYL 08. M 7. S 4095
CAN 04. AEND 33

P1421 Secondary Air System. Did you check it?

Originally Posted by Zulu95

P1421 Secondary Air System. Did you check it?

No I haven't, could you tell me a bit more about it:

Where is it?

What to look for?

What's its purpose?

Thanks much.

Look here:

http://www.realoem.com/bmw/showparts...26&hg=11&fg=50

I pulled the following info off of my scanner while it was running.


FREEZE FRAME
DTCFRZF: P0300
FULSYS1: OL_FAULT
FULSYS2: OL_FAULT
LOAD PCT%: 3.5
ETC: 163
SHRTFT1: 0.0
LONGFT1: 4.7
SHRTFT2: 0.0
LONGFT2: -20.3
RPM 680
VSS 0

These are some other readings from the code reader:
MIL STATUS: ON
MISFIRE MON: OK
FUEL SYS MON: OK
COMP. COMPONENT: INC
CATALYST MON: INC
HTO CATALYST: N/A
EVAP SYSTEM MON: INC
SEC AIR SYSTEM: INC
A/C REFRIG MON: N/A
OXY SENS MON: OK
OXY SENS HTR: OK
EGR: N/A

I unplugged the left and right side pre-cat O2 sensors. I then cleared the codes and started it up. At first it ran a lot smoother than it had in the past but that was short lived.

I took it out for a drive and as soon as I hit the gas pedal, the check engine light went out. This was the very first time I've ever driven the car without the check engine light. But the light would come back on when I took my foot off of the gas. The light always went out during acceleration and stayed off sometimes while coasting.

I cleared the codes while I was driving a scanned for new codes. While I was driving with the check engine light off and accelerating, I scanned for new codes and the only codes that generated were for the O2 sensors. When I ran the scanner again with my foot off of the pedal, I pulled the misfire codes for all driver side cylinders. I tried this method several times with the same results. Like clock work, as soon as I hit the gas pedal, the check engine light would go out.

my assumptions are:

If its not pulling the misfire codes while I'm driving then the fuel injectors are definitely getting power and spraying fuel.

there shouldn't be anything internal (lifters, cams..) because that issue wouldn't go away because I'm accelerating. If those parts were bad, they would always be bad even while accelerating and at idle.

Is the O2 sensor pre-cat driver side the issue or part of the issue or only a victim of something else?

Well this doesn't sound good. I ran the compression test and here are the results:

driver side starting from the front of the engine: 55psi, 54 psi, 120psi & 120psi.

passenger side: all came in around 180 psi.

I don't know how to interpret these results but I'm pretty sure it's bad.

I've already pulled the driver side valve cover off and I've attach pictures of the driver side spark plugs and pictures after the valve cover were removed.

Ok I finally got the intake manifold off.

My intake manifold gaskets, valve cover gaskets and throttle body gaskets all arrived today.

The gaskets that were on there were original BMW gaskets but who knows if they were ever changed.

I will start putting it back together tomorrow and then I will rerun the compression test and do a leak down test as well.

Below are pictures after the intake manifold was removed.

Even though a vacuumed the engine and blew compressed air around the intake area before removing the intake manifold, plenty of debris still fell down in the intake ports.

To get it out, I first stuck the vacuum down in each intake port, then I blew compressed air in there and finished it out with another vacuuming.

So far me favorite tool would be the telescoping magnet.