NEED HELP PLEASE! Rough idle and knock.

I have a 2006 bmw x3, 80,000miles I had the two lean codes and found that the intake boot had hole in it at elbow. I bought now intake boot and replaced it. During replacement i remove the disa unit. After putting all back together when i start the care it will barely run and at idle it makes a pinging backfire noise. when you rev it to 1000 rpm pinging goes away but still runs rough. please help.

Thanks,
Mark

Make sure you don't have a head gasket problem leaking fluid down into the cylinder heads very slowly. It may be a warning that a larger problem is about to surface. Check your radiator flow, if it is not flowing properly have a mechanic just look at it. Happpened to me and I caught it in time to get rid of car before major breakdown. Best of luck.

Did you happen to drop the pin from the old DISA valve down into the intake?

to me it sounds like you still have a vacuum leak. Check all the hoses around the intake and be sure you don't have another cracked hose or see if you knocked one loose or forgot to hook one up while you were working.

just noticed the age of the original post. Hopefully you figured this out by now. If not and you'd like help, shoot me a PM, I'm local.