E46 330d Turbo Dumping Sound

[osiris]

So Guys, I just received my brand new Intercooler from BMW and I fitted it about and hour ago and then took the car for a drive, there is definitely an improvement in performance but the Dumping sound is still there, it hasn't changed at all in fact I think its slightly louder.

The old intercooler as I said before had a very bad leak in it and the boost pipes didn't have any o-rings where they joined onto the intercooler itself.

Now having said all of this, I am still hearing a whistling sound which leads me to believe that I still have another boost leak somewhere, I will try find out where it is tomorrow and sort it out! once that is sorted if it is a boost leak that I am hearing I will let you know if the dumping sound is still there.

doesn't the 330d turbo have an internal waste gate? it has to release excess boost somehow I don't think this sound could be due to a boost leak???

Here is how bad the old intercooler was! you can see where all the gunk build up is there is a boost leak, when I filled it with water the water just dribbled right out!

and here is the nice new one

 

[Andy1GP]

Very Niice! You lucky fish! Luckily mine was still water tight, but just soo nice to have a fresh bling looking one like that shining through your front bumper mesh :thumbs:

 

[osiris]

Very Niice! You lucky fish! Luckily mine was still water tight, but just soo nice to have a fresh bling looking one like that shining through your front bumper mesh :thumbs:

Thanks :thumbs: Your right it looks very cool with this new shiny thing showing through my front bumper, Now to find the next boost leak! I'm going to try build a boost leak tester tomorrow, and a friend of mine has a compressor we can test with.

Hows your 330d coming along?

 

[Mike1]

The easiest way to increase the dumping sound on a diesel is to remove the DPF and replace it with a down-pipe, on the 330d motors I recommend a 76mm.

Furthermore, also consider removing one of the boxes on the exhaust system or even going for a larger diameter system with a single absorption box.

The difference is noticeable straight away! :thumbs:

 

[osiris]

The easiest way to increase the dumping sound on a diesel is to remove the DPF and replace it with a down-pipe, on the 330d motors I recommend a 76mm.

Furthermore, also consider removing one of the boxes on the exhaust system or even going for a larger diameter system with a single absorption box.

The difference is noticeable straight away! :thumbs:

Awsome so its not cause its stuffed, it actually does dump! I have a 63mm down pipe at the moment!

So could I just goto an exhaust place and tell them to remove a box and replace with a straight pipe and it should be fine?

 

[Twinz]

That old IC looks horific. You car should perform 10x better now :thumbs:

 

[Mike1]

Has the car got a dual or single pipe system?

 

[Andy1GP]

It's dual afaik. I've been quoted on a single large diameter exhaust for R2k right through.

@Osiris, I have to still check for boost leaks myself. I noticed some smoke coming out the engine bay (exhaust side cold start) today while working on some electrics and I have been suspecting a cracked exhaust manifold. That will be the next step. Just to find a trust worthy place that will fix the mani for me. Or find an affordable one. Not too keen on DIY exh header.

 

[Mike1]

I know the X5 uses a dual, and the E39 uses single.

Either way, there will be a middle box and a box before tips, replace with 76mm downpipe into 67mm or even 76mm if you want noise with a single centre sound absorption box.

While you at it, add twin pipes in polished chrome and you have the look, the sound and it makes the motor characteristics much more responsive as well as allows the turbo some space to breath as there is more flow so lower tempts etc.

R2k is not bad, for a full system down here we charge around R4k.

 

[osiris]

Has the car got a dual or single pipe system?

I will check tomorrow and let you know but im sure if Andy says its a duel system then it must be duel as we have the same cars only his is manual and mine is auto. :thumbs:

---

So Guys I did a dyno of my car with the new intercooler fitted, you can check it here: 330d Dyno Results

 

[osiris]

go google vnt turbo's .. no wastegate, no dumpvalve.

Look I don't know what to say to you? It looks like your trying to start an argument?? I have had the turbo checked, replaced the intercooler which had a huge leak in it which I thought could be making the sound and have now had the car on the dyno with very good results! I gained 90Nm ATW and gained 37 Whp from the new intercooler, so obviously the boost leak was pretty bad ass!

To me it makes logical sense that if there is excess boost it has to be disposed of! If it didn't get rid of excess boost then when you take your foot off the accelerator when the turbo is in full boost the revs wouldn't drop like they should as the car would still be boosting! am I right? so where ever the sound is coming from its a good thing!

 

[osiris]

So then you explain the noise??? and then tell me why Minimike19 has experienced this sound by fitting full exhaust systems and down pipes and why other diesels that my friends have do the same when they fit down pipes etc?

what exactly is making the sound then??? now that I have checked the full system myself and had a mechanic check it id love to know your answer...

 

[Mike1]

I would be keen to know too, since there is a very clear dumping noise when changing gears.

 

[Zack]

My friends Polo 1.9TDi does this as well. But much louder and has a higher pitch. It started to do this as soon as he did the "free flow" on the exhaust. He called it backspin. But a backspin is more of a chatter. But I told him regardless of what it is it's not supposed to do that. He also had it checked out by VW and they say there is nothing wrong with the car.

So it seems like the diesels sometimes do it when you start tampering with the exhaust. :dunno: I cannot explain it. But it sound awesome.

---

go google vnt turbo's .. no wastegate, no dumpvalve.

I am no expert... But if it's not a dumpvalve... what do you call the thing that connects to the Actuator? Isn't that some form of dump valve for over boost? Correct me if I'm wrong, but even if you close throttle and the turbo is creating more pressure than the current RPM of the car can "absorb" any excess pressure might be seen as over-boost? :dunno:

 

[Mike1]

As far as I know all turbo cars, even my smart which has no dump valve makes this sound, hell even the D4D bakkie I just drove does it.

Be it the wastegate, the release valve or whatever you want to call it I can tell you that every diesel I have ever driven of which there are any all dump to some extent nd any diesel with exhausts mods will audibly dump, chatter, whoosh and make a noise.

---

Please note the video below and the clearly audible dumping sound:

<iframe width="640" height="480" src="

" frameborder="0" allowfullscreen></iframe>

Is this not the same motor as the E39 530d and E46 330d use? Thats software and exhaust.

Trust me, it dumps!

 

[Andy1GP]

LOL guys, this isn't an argument. And let it not be one either. We are all learning right? I don't think we understand how the diesel concept works as well as netercol does, and how the turbo actually works in this closed system. My 1.8T petrol Audi A4 I had was also a closed system with no dumping whatsoever. The excess 'boost' just flows through the system like it normally does. So your engine is eating air with no diesel when off the pedal. Does that make sense?

Anyways, the noise, as good as it sounds I can't explain it. But here is an interesting link regarding it. It may be wear and tear causing the unique sound each of our turbo's are producing. Whether it be "blade creep" or bearing play etc. Just amplified through the exhaust system, which now has much less 'noise deadening' to it

http://www.bmwforums.info/general-g...el-turbo-common-faults-m47-m47n-m57-m57n.html

---

Maybe this is a better explanation.

It doesn't 'dump' to the atmosphere via a 'dump valve' or 'waste gate' but rather just through the engine.

 

[Mike1]

I am not arguing, Netercol has exclaimed these turbos don't dump and I am down with that.

However the noise in the vid above is the same motor and I highly doubt that much excess boost is allowed to re-enter the motor and end up in that sound out the exhaust.

I, and I think osiris are asking netercol where the sound comes from... That sound is loud enough to make my camera which is 10m away from the car distort on a gentle gear change...

 

[Andy1GP]

It could be that while the turbo compressor and turbine is under load the compressed air dampens the turbine noise, and when it's allowed to release, the compressed air is removed and then the high speed turbine and compressor is heard?

 

[Mike1]

If I can compare the sound to another vehicle, it sounds like one of those mad max suped up Subaru's on gearchange, you can actually ride the curve of the sound too by giving it just enough fuel and turbo spool and then let go and it dumps.

 

[netercol]

please feel free to delete wherever i am quoted in this thread.