My Z3 is making some alarming internal knocking sounds...

[peezen]

Hi there,

My 2000 Z3 2.3 has been giving me fits lately as it has been making a metallic clang/knock noise from inside the engine. I have included a video so that you guys can give it a listen and let me know what you think.



1. I have hooked the engine up to INPA and have the following BMW codes reoccur:

• 69 - fuel pump relay
  
• 238 - 243 specific cylinder misfire codes, all six
  
• 151 - Lambda Post Cat Bank 2 Limit Max
  
• 202 - Lambda Regulation Bank 1 Post Cat
  
• 203 - Lambda Regulation Bank 2 Post Cat
  
• 227 - Mixture Deviation Bank

2. Here are 3 shadow codes listed:

133 - CAN Signal ASC Timeout
11 - Tank Pressure Sensor (EVAP System)
127 - Activation Pump Solenoid

3. Mechanic had a quick look and thought that it might be a VANOS issue

4. Other issue that are probably not related but maybe:

• The ABS and ASC lights are both on but I can't connect with the ABS module through the OBDII port in INPA for some reason.
  
• The radio fuse blows immediately upon changing.

What I have done so far:

• replaced the MAF with a known working one = no change
  
• replaced the green relay by the driver side kick panel with known working one = no change

My wife would enjoy her car back so any input would be great before I start throwing money at it. I do all of my own work and have lots of experience working on my M70 and M62, and have worked on several M52/54's over the years, but have never run into this issue before.



Thank you in advance!

[Luftwaffe1O1]

Says video not available?

Aside from that, the fact that your radio fuse blows immediately means you are either replacing it with the wrong fuse, make sure the correct amperage is being used. If it is, something is causing surges in your system possibly.

Sounds like a quite a few gremlins, as for metallic noises, it can be as simple as noisy lifters, or it could be a loose spark plug. Believe it or not this has happened to me a couple of times with Bosch plugs. They come loose, and it will cause a dreadful noise. retightening it usually fixes it.

For reference, this is what that sounds like, my car had the same exact thing happen:

https://www.youtube.com/watch?v=Z5MpEN0vMt8

[peezen]

Video should be good now, it sounds a little more substantial than lifters or spark plugs, it's intermittent and when it's not happening the engine sounds normalish.

[z3forlife]

To connect to your abs use the under hood connector

[Tim95M3]

Sounds like the usual backfires through the intake that happen with a large vacuum leak. I'd smoke test the intake tract and see what's leaking. Most likely need to replace the whole PCV system and/or the lower throttle body boot.

Also - You'd have to access the ABS/DSC through the 20-pin round connector under the hood. I'd bet you have a fault for the yaw/lateral acceleration sensor.

[peezen]

Thanks so much guys! I do have an ADS connector with a serial port connection that I use for my 850i, I wonder if INPA can use it.

Ok, so I will have a good look today at the intake system and see what I find. I need to replace the oil housing gasket anyways so this will be a good time to do both.

I'll report back with my findings

[peezen]

So I replaced several hoses, and the upper intake boot, along with the pcv valve and the intake backfiring is gone! Thanks so much for the advice.

I still have two problems to fix now.

1. the fuse for the stereo keeps blowing when i replace it. It's a 20 amp fuse. Something must be amiss with the wiring no? Does the fuse box tend to have issues? The fuse on the back of the stereo is not blown.

2. I still have the abs and acs lights on. I cannot connect to the abs module through the OBD2 post, nor with the ADS port. I'm not sure that I have inpatient set up properly for ADS, do I only need to change the connection type from STD=OBD to ADS in the ediabas.ini file? Is there anything else? I can't connect to any modules with the ADS cable.

Thanks so much so far, I can finally get this on the road at least for my wife.

[Z3X2]

11 - Tank Pressure Sensor (EVAP System) Check gas cap then hoses from the manifold back to the evap
pump and the evap pump itself. Hope you don't have to replace the gas tank on the daughters 01 it was
a leak in the evap canister that is part of the gas tank not a fun job.

[peezen]

Thankfully that was a shadow code that has not tuned up again so far. The only issues as of now are the the radio and connecting to the ABS module

[peezen]

UPDATE: for anyone else that runs into persistent radio fuse #9 blowing, after unplugging first the radio, then the amp, the fuse still blew. I pulled the plastic container out from the right side of the trunk, and sure enough there were two CD changer wire harnesses. The small one was completely corroded and burned. I snipped it, taped it, and rerouted both harnesses, and replaced the fuse. The stereo works great now! All stock but the they all work including the sub. The previous owner thankfully wrote the radio code in the radio book so we were up and running quickly.

Just need to gain access to the ABS module to find out why I have the ABS light and ASC light on. Something is not working with my ADS/DIS.44 set up

[Vintage42]

... need to... find out why I have the ABS light and ASC light on...

Related...
http://www.bimmerforums.com/forum/sh...1#post29357461
http://forums.bimmerforums.com/forum...=diy+asc%2Fabs

[djb2]

I assume that the 'backfire' noise has not returned.

That noise is also a characteristic of a major leak in the CCV system. It's likely a broken CCV valve, but may be a failure of one of the hoses attached to it.