[Smoothound]

After reading this and a couple of other posts, I decided to bypass the EGR. It's fixed the problem for me!

The EPC is still in place, but not making the noise now the EGR is not present. So if this isn't an EPC fault, it could actually be a EGR fault or degredation (maybe CBU?) causing the EPC to oscillate?

As I hoped, it's also sorted by boost problem (ebbing and surging when on partial boost).

It's all good.

Next stop - DPF. Didn't know the thing existed till I started to investigate this issue. Anyhoo, that's for another thread.

Thanks to E90POST for being such a great resource!

[Smoothound]

I wanted to wait some time before posting the next bit, as it sounds a bit crazy. But....the EGR delete has also fixed my brake judder problem.

I can only assume the oscillation from the EPC makes it's way into the vaccum used by the brakes?

I'd replaced bushes, disks, pads, everything. Nothing worked. First drive after EGR delete and the brake judder went away and it's never come back. Hope this helps someone else.

[GamezGuru]

I have exact same symptom as OP, noise stops when I pinch the vacuum line to the EGR valve. I've ordered a new pressure converter and vacuum lines to fix it all myself at the next opportunity... are any special tools required to remove the manifold on the 330d? Or just typical Allens and sockets?

I'll also be cleaning out the manifold and replacing seals whilst I'm at it

Amazing resource here, just won a new member...

[Dibbles00]

Originally Posted by GamezGuru

I have exact same symptom as OP, noise stops when I pinch the vacuum line to the EGR valve. I've ordered a new pressure converter and vacuum lines to fix it all myself at the next opportunity... are any special tools required to remove the manifold on the 330d? Or just typical Allens and sockets?

I'll also be cleaning out the manifold and replacing seals whilst I'm at it

Amazing resource here, just won a new member...

No special tools are needed pal. Straight forward job and remember not to tighten up the bolts too tight when putting manifold back on. Most fiddly thing is getting bracket back on the back of the manifold.

[GamezGuru]

Thanks fella,

Sorry I hadn't subscribed to the thread, and wasn't expecting such an insanely fast response! Do you know specifically what sized hex bolt holds the converter on? Or any other spanner sizes I need for that matter (I'll be borrowing some tools for this)? It doesn't mention on realoem...

Much appreciated,
Ciao

[Dibbles00]

Top of my head I think 8mm or 10mm for pressure converter. Loosen both and remove one and it will slide out.

The rest can be achieved with a regular socket set. However you will need a few torx sockets for the braces.

[GamezGuru]

Me again!

So after a few months of this quacking sound, i finally got round to the job this weekend, but i should first mention the change in symptoms on Friday evening... after having my car washed i got the engine emissions warning light. Didn't strike me as a huge deal as i'd had it come on one day after a mechanic inspected the issue months ago. However, the following morning i had to take it out briefly and i noticed the quacking had stopped! I could only assume the pressure converter had finally died and it was plain luck that i planned to fix it this weekend.

Anyway, so i successfully removed the manifold and EGR, gave it a caustic soda treatment as recommended on bimmerforums, replaced all seals as well as the pressure converter and reachable vacuum lines (4 in total). Reassembled everything and engine started fine - without quacking - but the emission light is still on?

I am just gonna eat dinner then head out to fit the remaining superficial stuff, cabin filter and engine braces before i take it for a drive, to see if it feels ok, so if you have any thoughts please chime in! What specifically could the warning light refer to? And how can i test that the EGR valve itself can move freely?

Thanks in advance, I'm gonna be a little nervous commuting tomorrow...