With an aftermarket turbo, are you sure the wastegate is adjusted properly --- that it's closed tightly?

You can test the WG hoses and tank for leaks too, just don't apply too much pressure.

 

 

 

My bet it’s your turbo boost solenoid located under the intake manifold. Tends to make a “moo” sound on shutdown when they go. Look it up on YouTube.

 

 

Ok, well here’s an update. I have so far since I last posted, replaced the vacuum lines, tested the vac tank and pump, replaced the boost pressure converter, EVAP purge valve &hose, and replaced the intake manifold gaskets & throttle body gasket. All with no change. The wastegate and actuator are functioning properly as far as I can tell. I have previously pressure tested the fmic and charge pipes. I smoke tested the car as well as I could and everything looked ok. I think I need to do a full system pressure test.
My problem is I have a question or two that I’m unsure about. If a guy was to attach a test rig to the turbo inlet, and introduced pressure, will that work? Or will it just flow through the cylinders and out the exhaust if any valves are open? Do I need to plug the tailpipes too? Is there even a good way to pressure test the intake manifold? Someone save me from my brain! Lol.... I’m tempted to just go try it, but my brain keeps saying even though it works on other cars, this is a MINI, there must be a reason I need to do something differently than ordinary.

 

Ok, after a bit of reading, I have determined that I should be ok doing it this way, since the VANOS system doesn’t allow for much in the way of valve overlap (as in having intake and exhaust valves open at the same time time in the same cylinder). It’s getting nice and dark out now, so I’ll have to give it a go in the morning. In the meantime, if anyone has anything else about why this won’t work, I’m all ears. I have been fighting this damn thing for so long, I’m almost ready to to throw my arms up and just decide ”that’s just the way this one is”. But I am pretty positive that it’s a boost leak I just haven’t found yet.

 

I may have the same thing you do, just random acceleration blow off is what i say mine sounds like. The typical, but much software than normal blow off,, pssshhhhh sound. Sometimes long, not just a psshh but a pssshhhhhh.
its typically under light acceleration where boost isn’t even near building per say. Just taking off from a stop light or stop and go turning a corner.
to me it is the recirculating valve, but cant prove it, it would be nice if the Schwaben or other tool like dash command could report when the recirculating valve is engaged. This would tell us, but wouldn’t tell us why persay unless there was more data there to be seen.
from what i can tell it never did it until i started adding mods,, way before the stage 3 tune and prior to the JCW turbo install which was before the tune.
maybe after the K&N CIA or the Alta recirculating valve spring...
so i dont know if the valve spring is holding the recirc back form letting pressure go to where its soft enough we wouldn’t hear it, but the Alta spring holds it back a little longer so there is enough pressure we hear it.
because the stock intake is closed it may have been doing it all along but I couldn’t hear it.
i have not done everything you have done because i dont believe it to be a vacuum leak, but the recirc valve blowing off.
but the question still remains... why..

 

They do sound fairly similar. Mine is not the diverter from what I can tell, but who knows? I don’t hear the solenoid activation that helps make the pshhh sound when it does it though. Just a teakettle type whistle for like 1 second and a small drop in boost (around 2-3 psi). It seems to happen quite often right before the diverter opens, but that could realistically be from me lifting my foot when I hear it also. Pretty sure I’m tracking an oddball boost leak, but who really knows at this point. I am beginning to hear a little bit of an air rushing sound when in boost, so I am assuming that it is getting worse, or now I have more than one leak, lol. It’s more pronounced than the intake sucking air.... and just...... different. The funny thing is I have no codes and the boost builds and hold fine otherwise. Going to try to pressure test it today and maybe introduce a bit of smoke too, depending on how it goes. I’m wondering if I maybe didn’t get the boost tube cinched right on the throttle body when I took the intake manifold off the other day. I need to check the clamp.
Edit: I forgot to add, that a friend has the same exact symptoms you do, we talk a lot about it, trying to figure them out. He has tried different diverter valves too, with no solution. He is stage 2 with a stock turbo. As a matter of fact, he just had a brand new engine installed by the dealership (piston practically vaporized) and is still getting it with the new engine.

 

The solenoid doesnt make noise, you only hear the pshhh, mine will make a hissing noise too, like the solenoid is stuck open, but it wasnt making that noise until i started accelerating, and the stock recirc and brand new one do it.
well maybe an after market recirc solenoid makes noise but the stock doesnt.
in my eyes a leak would be less prone in low boost and more in high boost, unless its a vacuum leak not a boost leak.
So if its the recirc its what ever controls it. Which i have no clue what that is, i imagine the boost solenoid under the intake?

Did you notice it when the car was still stock?

 

Yes, it did it stock too. I checked the clamp on the throttle body boost tube joint, it was a little bit crooked, so I fixed that and it took care of the audible air rushing noise and lack of power I was experiencing, but the little hoot/whistle is still there. If it was constant, I would probably just think it was turbo noise or something, but it’s a short quick noise and the hiccup that goes with a small drop on pressure, I can watch it go on my gauge, always drops about 2 psi when I'm around 5-10 psi.
Now that I think about it, I think it started happening after the turbo replacement. I’ve always wondered if it was just a weird harmonics or something in the diverter air passage, and that’s what I hear, but I really don’t think so. I’m pretty sure its some kind of leak that lets go under lighter pressure but closes up under heavy boost. But that’s mostly just .... intuition? A feeling?.. not just a feeling obviously, but a ... slightly educated guess based on what I’ve learned and what I’ve already checked and replaced. It’s one of those deals where I thought I had it nailed down and fixed a couple of times now, but it never is, and nobody has a clue other than vacuum system, boost leak, diverter, or ? Lol.... I’m almost starting to wonder if it’s the valve cover or something, but I’m pretty sure it isn’t. There isn’t much left to replace at this point except that, part of the stock turbo piping and the intake manifold & throttle body.....which I’m starting to wonder about too! Lol. At least I’m not, for the most part, just throwing parts at it, most of the stuff needed replaced. But there have been a few diverter valves along the way. I even took off my DV+ and went back to a factory diverter, just to see.

 

It’s dang frustrating. And only when at partial-low boost. When it goes 12psi-full boost it will spool quick and the only thing I hear is the turbo itself and the engine/exhaust combo shouting out loud. No pressure drop, holds boost...aaaaarrrggghhh! I really need to get outside and get the pressure test done! I guess I should get off my Grumpy butt!

 

Ever consider putting the stock air box on it for a time to see if the noise you hear isn’t anything more than the cold air intake making normal turbo noise more obvious?
especially if the wastegate actuator is starting to open the astegate enough you get a little whistle from the wastegate loosening up before it opens?

 

I do use the factory airbox for most of the year, only use the cone when it’s not as warm out, because it keeps the IAT’s lower. I is definitely quieter with it, but I still hear it... and it bugs me! Lol... that’s a damn good point, I wonder if it is just the wastegate opening up a little bit.

 

Wait... you use the CIA when its cold out, and the air box when its warm?
the tune isn’t meant for the air box as its air is restricted compared to the CIA
the stage 3 may be able to be coded for the stock air box, maybe not I’m not sure because Mario’s requires are for it to allow more airflow as the JCW turbo sucks a lot more air.
if you are running the stock box you my be pulling on the intake too hard causing a whistle somewhere.
can you confirm it happens with the cold air intake on it too?

i know the stock box has quite a bit of air flow but not as much as the stage three and jcw turbo needs
unless you mounted a stock JCW air box.

just a thought

 

Guys I may have the same issue, too. I have the 09 MCS and while it was stock, everything was just fine. Then as I start modding, particularly right after the Alta diverter spring, FMIC, noisemaker delete, and charge pipe muffler section delete (those deletes I used Bimmer Dude's method of fabbing up some 2" aluminum pipes), I immediately noticed a funny feel during partial acceleration and partial easing of gas pedal. I feel this weird and transient "deceleration" feel in a split second on two occasions: 1) During acceleration no issue, but the instant upon easing, it slumps down and throws the car forward a bit, then back to smooth drive/coasting. 2) Same slump down felt during low gear shifting at spirited acceleration. Those two are the best way I can describe mine and there's no error, engine light whatsoever. Just like Grumpy mentions, if I get on hard acceleration, it runs good and strong, no issues.

Although I did upgrade my tune to stage 2 recently, the tune is from RPM and it does help smooth out the edges a little bit on the issue, the issue is still there. I too thought it to be boost leak, so I checked all connections and replace some of the hose clamps just to be sure. None of it helped. I'm subscribing this thread to see if there could be a solution to it.

I'm leaning towards these causes (from my car and mods):
1) Alta Diverter Valve Spring, may be the spring is too stiff? While easing on throttle, it should have immediately let off the throttle back pressure and it just didn't? This I may check this weekend by changing the spring back to stock.
2) Those muffler and noisemaker deletes in the intake? I really couldn't see this, but could the intake muffler serve as a buffer for throttle back pressure to ease out some of the air inertia? This is beyond my guess and hunch.
3) Could FMIC have anything to do with this at all?

 

Morning Grumpy,
in the last month I have had two customers with a leak coming from the round metal gasket that is sandwiched between the turbo and manifold. Not the easiest thing to check, but apparently it happens

Mario

mQubed Motorsport Manic & RPM Power Tuning

 

Lol, no, no....the opposite.....the factory airbox goes on in warm weather, because I can see the difference it makes on intake temps with dash command. The cone is more of a hot air intake! Yes, it was on when Mario tuned it. It was summertime.
Yes it does it regardless of the intake, but it is much quieter with the factory airbox on. With a better filter it flows very well in the Countryman. But it sounds sooo much better without it! :-)

 

Interesting, what a PITA to check, lol I used a new one, but that’s no guarantee of anything. I’ve been banging my head against this damn noise forever. This is probably as good a reason as any, lol. Thanks Mario.
I’ve been beginning to wonder if it’s maybe a leak at the downpipe? Or maybe like said earlier, it’s the wastegate...... I maybe buy that, because yesterday I found a nice straight road up an incline, with nobody else around. So I drove up it holding an even 3 psi, just barely pressing the gas, and as the wastegate cycled, I could hear it. And it gave me the hoot a few times, in rhythm with it. At least I think that’s what was happening. I was only using my butt, my ears, and my boost gauge. So I honestly don’t know how fast it really cycles, but I swear I could hear it. A possible theory I have going is that under very light pressure, as the wastegate either opens or closes (??) it’s just right to whistle across the opening like a reed in a woodwind.
Either that or I have a wacky boost leak that only opens up under light boost, but closes up tight under higher pressure? I swear I will make myself crazy yet!
Thanks buddy

ps yet another pressure test found nothing, but maybe I need to do it at around 5 psi since it only seems to happen at low pressure.

 

If it was, would a guy be able see a streak of soot or anything? Like you usually can on a manifold leak, for instance?

 

Update:

Ok, I haven’t been able to do a good pressure test for a while because my air compressor crapped out. But I borrowed one from a friend the other day, and just went and did one.
The test was good. It holds pressure fine and I can’t hear anything at all leaking out.
Now I’m more confused than ever. I’m starting to think that it must be a leak either in the turbo/downpipe gasket, or the donut that Mariokart mentioned above.
The problem is, I’m not sure how to check those without disassembling the thing to check. I have a downpipe gasket sitting here that I picked up somewhere along the way. So at worst, I can try changing that. But other than just visibly looking for a streak or spot of soot around the joint, I don’t know how to check the donut.
If anyone has any suggestions I’d be happy to hear them. I am trying to avoid taking it back apart.
At this point i would just say “it’s just a noise it makes “ and live with it. But I know it’s not right, because of the small amount of boost drop when it happens.
Thanks

 

Updated update:

heh...... well if it’s not THE problem, I think I may have found A problem.
After posting the update above, I went and pulled the heat shield off of the turbo. Sure enough, there’s blow-through on the inside and on the downpipe flange, in the front (towards the front of the car) you can see in the photo where I wiped a finger across it. I suppose I will pull it up on some ramps and change the gasket and see if that makes a difference.
I don’t mind replacing things when they need it, like this gasket... but I just hate throwing parts at something to try to fix it! And the dealership is the worst about doing it! They just read the code, if you are lucky enough to have one (this problem has never given me a single code), and proceed down a checklist of parts to replace until they fix it. Or they replace the first one on the list, tell you it’s fixed, then let you come back when the issue presents again, then replace the next part........ ok enough ranting, I’ve been watching too many you tube investigations into crooked dealerships and repair shops.
After I get this sucker replaced, I will update the post to let anyone that’s still interested know what happens.
Here’s the photos of the soot blow-out


You can see the clean-er spot on the flange where I ran my finger over it towards the bottom of the photo

You can see the discoloring and soot spots below and to the left of the 02 sensor hole

 

Ok..... good news and not so good too!
Well I was going to swap out that gasket yesterday, then I noticed that I had a low tire. So I tightened up the nuts on the downpipe flange a little bit, and put the heat shield back on, so I could run to Les Schwab. On the way there I tested it a bit, and some more today and tightening those up seems to have made a tremendous difference. I can only hear it pretty faintly now, when it happens... much quieter than before, and it is doing it far less often to boot.
Now I have thought that I had it figured out before, a couple of times. But I really feel like this is really it this time. I won’t know for sure for at least a few days though. Because.........
..... The bad news is that apparently my tire is not repairable. So now I need to spend my free time searching for a good deal on a decent tire that won’t break the bank.
It’s always something

 

Ok, I haven’t gotten to fix the gasket yet, because I’m still doing a Grumpy tire shopping tour. But after droit around a little more today, I’m even more confident that the downpipe gasket has been the culprit all along. After tightening the nuts on the flange a little bit yesterday, it has been VERY noticeably different. The noise is much less frequent and not as loud. The car is responding better too.
I never would have guessed that an exhaust leak would be the problem. I mean, I’ve had a lot of cars over the years, and a lot of exhaust leaks, lol. But I’ve never heard of one that gave the symptoms I have been getting. Aside from the fact that it is brief and intermittent, I would not have thought that it could cause a boost drop like that. It is just really odd to me, but it does look like that’s what it is! Does anyone know why it would cause a boost drop? I know that flange is RIGHT past the turbo..... but it IS post-turbo, so shouldn’t (in theory) make any difference to boost pressure. Unless I’m wildly mistaken about how these turbo’s work, all of the pressure should be being built on the other side of the wastegate.
I don’t think I really have much back-pressure to speak of, exhaust-wise. It’s a catless downpipe, and I have both the secondary cat and resonator deleted. So aside from the section of flex-pipe and the factory suitcase muffler, there is nothing in the way.
I can take a look at the flex section when I change the gasket, since I will need to crawl underneath to loosen the V-clamp a tad to be able to move the downpipe. Other than any obvious physical damage to it, I don’t think I will be able to see much.
I have seriously spent SO many hours online trying to find anything about my symptoms. There was nothing. And I was looking at everything..... BMW, Audi, VW, and so on..... so many forum posts! Lol.
Has anyone else seen something like this?