How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask George Your Own Question
George, BMW Technician
Category: BMW
Satisfied Customers: 1861
Experience:  BMW Master Technician over 20 years BMW Dealership Experience. BMW Auto Repair Shop Business Owner
Type Your BMW Question Here...
George is online now
A new question is answered every 9 seconds

2000 BMW 740IL: Loud noise..convertor..rpms but stays..think a pulley

This answer was rated:

2000 BMW 740IL Question...... Loud noise coming from transmission convertor area. The noise comes and goes with rpms but stays with idle. At first you would think a pulley of some sort or belt noise. A much louder noise though. Thank you liz
Pull out the engine oil dipstick while the engine is idling and see if the noise changes. Let me know what happens.
Customer: replied 7 years ago.
Will be trying this in the am. how do i get back to you? Txs Liz
Just respond to your question and it will send it back to me.
George and 3 other BMW Specialists are ready to help you
Hi Liz you did not have to open another question all you need to do is respond back to this question.
Hi Liz
Customer: replied 7 years ago.
Hi George 1st time using this not familier. George we pulled dip stick out and noise stopped. Vaccum related? Did look up tsb's Crank seals area and howling noise which is right on........ Looked up type of vaccum system on vehicle. Back of engine intake pulled tube off which feeds brake vaccum and y's off to throttle body intake. Plenty of vaccum in engine. Are we on the right track? Thanks liz

The problem is your Crankcase Vent Valve has gone bad and will need replacement. It is allowing major buildup of pressure inside your engine which will do major damage internally quick. So do not run it unless the dipstick is pulled out so the pressure has somewhere to escape. The noise you are hearing is the pressure inside the engine escaping past the rear main crankshaft seal thats why you have the high pitch noise.

If you give me the last 7 digits of your VIN # XXXXX will look up the part for you.

George and 3 other BMW Specialists are ready to help you
DPO9429 Is not coming up as a valid VIN # XXXXX if you can double check to make sure this is correct.

Liz these should be the correct parts that you need to change, # XXXXX is the Crankcase Vent Valve. You will also need # XXXXX


Thank you very much for the Bonus,



No. Description Supplement Qty From Up To Part Number Price Notes
01INTAKE MANIFOLD109/199811611435361$615.48
06Blind plug109/199811611704792$9.56
07Vent pipe109/199811611742826$30.86
16Hex nut with plateAM71009/199807129902630ENDED
16Hex nut with plateAM7 ZNNIV SI1009/199807129905541$0.64


George and 3 other BMW Specialists are ready to help you

Thank you very much again I closed the other question for you so you will not have to worry about it.