[mweisdorfer]

Ok I had to take the intake manifold off my wife's 08 x5 w/ n52 motor. I had to get to the crank case breather hose, which is connected on the inside of the intake manifold on two parts and then on the backside of the motor on the spark plug side of the engine. The breather hose was bad and it was leaking oil all over the interior of the manifold. So, that problem is not fixed. BUT>>>>>>

I put all the parts back together and started the car. It hesitated then stalled. I cranked over the engine several times. Nothing. So, I went on-line too see if I could google the issue. THE MAF kept coming up. The engine, as it was, would somewhat hesitate on cold days upon start up which could be a sign the MAF is not functioning properly but not enough to throw codes. I unplugged the MAF and the started the car. It runs fine. I plug the MAF back in, and it hesitates like crazy. So, I ordered a brand new VDO MAF and plugged it in. Problem still exists I can't start the car and keep it running when the new MAF is plugged in.

The only thing I can think of is that the wire from the electrical box and the connector is bad or the connection on the other end is loose?

Please Advise...

[CHECKERED]

Originally Posted by mweisdorfer

The only thing I can think of is that the wire from the electrical box and the connector is bad or the connection on the other end is loose?

Please Advise...

I had that happen on my old Altima, so it’s possible

[Three_thirty_I]

Did you disconnect the battery and leave it for at least 20-30 minutes when fitting the new MAF? It could be adaptations - when unplugging the DME runs from factory mapping since it gets no information from the MAF. When plugging a new MAF in, my understanding is that it still uses stored data along with the new MAF readings.

Before the intake manifold was removed, I presume there were no issues? Did you replace the 6 rubber gaskets for the intake manifold, and for that matter the green rubber throttle body gasket? Basically trying to rule out vacuum leaks.

[Jeff@TopGearSolutions]

If you have a tune or Bavarian Technic tool you can try resetting adaptations?

[JamesM3M5]

You have a major vacuum/unmetered air leak in the system. Typical mistaken diagnosis is to replace the HFM, which is not the problem.

Check your purge valve connection at the back of the throttle or some other item you may have left loose or disconnected.

Also this is not the N52 forum, this is for the N54 turbo cars.

[Three_thirty_I]

Yep, only found this thread by accident since I am mostly active on the NA side...

[Three_thirty_I]

So, no feedback to our replies?!

[mweisdorfer]

JamesM3M5 was dead on.

I did not plug the purge valve back into the backside of the throttle body. The engine is black and the valve is black. Everything sort of blended together. I was working on it by myself. Probably would n't have had this issue had a had a friend looking over my shoulder and helping me that day. Oh well lesson learned.

I found it after taking things a part and getting down to the throttle body and looking every thing over with my flash light and then I noticed the end just sitting there without the valve attached.

Its amazing what one connection will do

[Three_thirty_I]

Glad you got it sorted out!!