XSeries-forum

Don't think the quack is at fault just one of those things.
Ans yes a good clean while you have it all apart will do no harm.

The ecu uses the maf to see if the egr is working so it's possibly all related to egr operation still

Back home tonight to change the vacuum pump tomorrow, it finally arrived, have a MAF on order also at a significantly reduced cost thanks to a German online supplier. Had a Bluetooth OBD connected today and was throwing up all kinds of faults during a 300 mile drive. Throttle was very flaky around the 2000 rpm mark. Fingers crossed for tomorrow!

Replaced the EGR Pressure Actuator this morning, all working fine again.

No need for the MAF I ordered, changed all the seals on the inlet manifold also.

Good job

Leslie wrote: ↑Fri Apr 15, 2022 5:20 pm Good job

Thanks for your help Leslie! Much appreciated!!

No worries

Sounds like you put the belt on backwards. Yup, thats a thing. Especially a problem with high mileage belts.

Carefully drip water only on the belt to confirm.

The pulley grooves on the new alternator are likely machined different than oem or belt was extremely worn and/or delaminating, flipping belt will cause old belt grooves to pull/ stress into new grooves and a engine rotation is what it takes for belt to load-unload into the new pulley tracks and/or slide the delaminated section creating the noise... usually its a combination of both on a old reused belt. No, you cannot flip belt back without risking total immediate failure especially if its a delamination.

If belt was replaced with alt, its a defective belt or terribly machined offset pulley grooves...

No that noise was definitely the EGR Pressure Actuator, and well documented on the web.

Drove a couple hundred miles since the Actuator change and now getting error code - 4501 EGR Control Deviation

Found elsewhere for this error: Vacuum leaks seem to be what it points at.

Check the following potential problem sources:
Leaks in mass airflow system on engine side of compressor
Leaks in exhaust system on engine side of turbine (combined with mass airflow plausibility errors).
Throttle valve defect (in combination with throttle valve faults).
Defective EGR valve (in combination with EGR valve errors).
Defective turbocharger (in combination with turbocharger faults).
Severe EGR cooler soot accumulation. Applies to engines with single-stage boost: Conduct mass
airflow system test.

Worth checking all of the hoses as well.

Any indication of your brakes needing more effort? There’s one report of the brake servo having a leak.

I changed out some of the ropey swirl flaps in case that was causing a problem but didn't help.

I also changed out the MAF with new which gave a performance and mpg boost for motorway driving.

Now regularly getting the following error codes:

4BB6 Air mass meter

4501 EGR deviation control

Have I bought a faulty MAF or is this a symptom of the EGR issue?

Thanks

4BB6 - Have you reset the MAF adaptation values? The TIS says this is necessary using the BMW Diagnostics System if the MAF has been replaced.

4501 is as above. A blockage, leak, soot accumulation or bad sensor.

You should also be able to reset the MAF if you disconnect the battery for 30 minutes.

Yes reset adaptation values, ran the ista mass air flow test and it failed, which is why I'm suspecting a faulty MAF....

Changed EGR valve yesterday still no change...