E46 Fanatics Forum banner
1 - 3 of 3 Posts

·
Registered
E46 F10 W204 W212
Joined
·
5,317 Posts
Discussion Starter · #1 · (Edited)
I'm posting for others that may experience this in the future. This issue is resolved for me now, but I'm hoping future searchers will have a faster time diagnosing this issue as a result of this thread. This happened on my 11/02 build 325Ci with the M54B25 motor with 88k miles. No "mods" other than the NGK Iridiums I put in for shiggles.

Symptoms
  • Growling noise when turning to ON (but not start) in the morning. Sounds like the Chewbacca sounds commonly associated with the CCV, but louder and with a lower frequency. On some instances the vibration is felt through the floor.
  • Sound comes from the front, towards the floor.
  • Growling continues after start, and doesnt go away until the motor warms up to full operating temperature. You can still hear it sporadically after warm up albeit at a much lower volume.
  • Growls are most noticeable when letting off the gas after a spirited acceleration. This is when you feel it coming through the floor.
  • Power cut-off at WOT, with a sensation similar to hitting the brake when in fact you were flooring the gas pedal. This symptom manifested later on, and would have helped me skip the other parts I replaced if this showed itself earlier.
  • At 1/3 tank, the left fuel lobe had approximately the same amount of fuel as the right lobe, checked via the hidden cluster menu 6.0. This is a symptom that has been described by others when their fuel pumps were close to failure.

Replaced, in order
  • DME fan
  • CCV and related hoses
  • Fuel Filter
  • Fuel pump - this fixed it

This problem was tricky because all the growling sounds were coming from up front. It wasn't until the throttle lag at WOT and correspondence with other members did I finally replace the fuel pump. On a side note, BMA had the best price for the VDO pump.

Time between the first growl until the car started to choke at high rpm was about 4 weeks. Note that because I don't drive this car everyday, I had a chance to take my time. If you're having these growling sounds and you put more miles on your car than I do, time between noise to failure might be significantly shorter.

I corresponded with a few guys about this issue, but I'll let them share if they feel like it. As mentioned this issue is resolved for me now, but thought I would post it for the benefit of future searchers. E46s are getting older, so the likelihood of growling noises and failing fuel pumps become more likely every day.

Before all of this I thought the suggestion to replace the fuel pump at a fixed mileage or time interval was unnecessary, especially since this car is primarily driven on the freeway on the weekends. I'm starting to think there's good merit to that suggestion.

Edit 03/05/17 : Here's a video that illustrates the growling. Sounds a bit different when heard from inside or outside (this is outside obviously) but you'll get a good idea of what I'm talking about when switching the ignition to ON.

https://youtu.be/YDY6f7gRwgk
 

·
Registered
E46 F10 W204 W212
Joined
·
5,317 Posts
Discussion Starter · #3 · (Edited)
cvx5832, I just wanted to thank you for posting your solution. My 2002 330ci just had a fuel pump failure at 235,000 miles with the exact symptoms you described. Your post helped me to fix the problem with certainty that the problem was the fuel pump.
No problem. Thanks to Kalim too. He went through the same thing and gave me the certainty I needed that it was indeed the pump, even though the symptoms pointed elsewhere. Since I never saw the problem+solution documented in the same thread before, I posted it for whatever benefit to the next guy.

And 235k, wow. I barely got 90k out of mine...
 

·
Registered
E46 F10 W204 W212
Joined
·
5,317 Posts
Discussion Starter · #9 ·
The "foghorn" sound was very puzzling to me at first. I'm thinking it has to do with the fuel regulator not receiving enough pressure or enough constant pressure when the fuel pump is soft failing that causes the regulator diaphragm to vibrate loudly.
This is what I was thinking too, a resonance vibration of the FPR diaphragm.
 
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top