Hello there....so heres the problem I have been having... Whenever I'm getting on the car.. it seems to sometimes hesitate real bad... I hear some clicking... and then a pretty big cloud of black smoke is emitted out of the tailpipe. From my research it looks like this is what is called "Super Knock" and is caused either by carbon buildup or HPFP problems. I dont get the hesitation all of the time... only about 60-70% of the time but am very certain I'm "rolling coal" or throwing black smoke pretty much everywhere from the number of people asking me if the car is a diesel... or that its smoking.. or that if something is wrong with the car hahaha... Ive heard them all... trust me. I just had the walnut blasting and a new valve cover done last month so that should take carbon and the PCV valve out of the equation correct?

Now onto the HPFP... I've looked up symptoms of a bad pump and I dont think I exhibit any of the symptoms. Car doesnt stall at all... has never stalled actually. I'm not getting bad MPG... around 28/30 MPG in town and I'm not throwing any kind of codes besides a P115c code because of a vacuum leak someplace... prolly the intake inlet. But no other codes or half power symbols lighting up or anything like that. I'm using 93 octane from a few different stations so dont think its bad gas. This has been going on for a few months.

Whats weird is this all stated after installing my DT Turbo Oil line..which was an absolute nightmare... But the smoke that comes out is black... not white or blue... so it has to be something fuel related or something. I pulled the plugs and it does look like I'm running really rich... car back fires alot when I shift. Kinda hoping someone can shed some light on this or give me your opinions on this. Its kinda embarrassing throwing smoke everywhere I go and having old ladies pulling up to me at stoplights telling me something is wrong with the car. Car is modded... mods are in signature... Intake/FMIC/Catless DP & fJCW Exhaust. Car is a 08 MCS. Thanks in advance.

 

Could be your map sensor in your manifold miss reading boost throwing out your a/f ratio. Pull it and check if its coated with oil if so gently clean it and see if things improve. If you know someone with a MINI Cooper S swap sensors and see if it goes away. You can pick them up pretty cheap on eBay.

 

I suspect that it has to do with your P115c code. That could possibility throw off your AFR.

Was that code before there before the problem started? I wonder if you knocked something loose or re-hooked up something incorrectly after you installed the oil feed lines.

 

Well the only other thing that could be causing the P115c code is there being a crack somewhere in the intake inlet or the rubber piece connecting from the inlet to the PCV valve. I just havent replaced it yet cause I have a JCW turbo waiting to go in and need the JCW inlet cause the MCS one is to small from what I've read. But to answer your question of if the code was there before the turbo oil line install... then yes it was. Was told it was the MAF by BMW (closet Mini dealer is 2-2.5 hrs away)... replaced the MAF. Researched it might be carbon buildup... had it walnut blasted... then saw oil on top of valve cover by PCV... so replaced the valve cover. Cleared the code via the Torque App but comes back 5 minutes later.

But Ill check the MAP sensor and see if that may be the problem. Thanks for the responses.

 

Have you looked to see if your throttle body is all gunked up. Build up in the unit can cause a restriction and the code.

 

My MAP sensor has a little oil in it when I was installing my Forge DV, I shot some electrical cleaner in there and shot compressed air to clear it out. I wasn't having any issues prior to cleaning my MAP sensor. A backfire is when the fuel/air ignites before the intake/exhaust valves are close, other posters can this be a timing issue?

 

Are you tuned at all? I too have a similar issue. I learned I can keep it at bay as long as I'm in a lower gear when accelerating hard. If I'm to high a gear is when it happens to me. I also walnut shell blasted. We might have the same symptom but maybe different cause? Not sure. Typically I hae to be in 6th or 5th going at a lower speed, full throttle, then it hesitates, click, click, click, puff. Then all is normal. I also have suspected the catless DP not providing enough back pressure and it happened shortly after I installed it, but that could be me reaching for any explanation.

 

Similar to this video?




That's my car, mine was caused by air/fuel being way too lean. That was WOT at 3000rpm in 4th and 16PSI. AFR was 14:1. Now after adding fuel to my tune I can hit 17psi with no issues. Your vacuum leak might cause the issue, adding un-metered air so it runs lean. Of course once your in boost you should be losing air, which would make it rich...

 

Question. Whats your torque app indicating for boost, timing and AFR just before and when it happens. I'd be concerned that my timing chain drive sprocket may have slipped. It is not keyed to the crank and only held in place by compression load from the torque on the bolt. Another brilliant BMW/Peugeot oversight.

 

No I'm not tuned at the moment. Have been thinking of either going with the AP or somehow getting the Manic tune here next summer. For me it usually happens in 3rd and/or 4th gear. Doesnt always happen but does it more times than not. But I know what you mean by reaching for an explanation cause if started immediately after doing the turbo oil line replacement. But everything leads to a fuel problem.... so IDK.

 

This is pretty much exactly what I'm talking about. I'm only running stock boost and it holds just fine. But ill look at the map sensor... and get the vacuum leak taken care of and see if thats the issue.

 

Just to update this... checked the map sensor about a week ago... pulled it out... wiped it down... and put it back in and so far no hiccups or anything. No huge puffs of black smoke afterwards either. Gotten on it about 10 times since then and all is great. There didnt really seem to be anything on the sensor that I could see but whatever. Thanks again scubbysnacks for suggesting it.

 

What was your frequency before? How many days might pass before it happened? I see you said 60-70% of when you got on it. But how often would you 'get on-it'

 

Not really sure of the frequency... hard to say really. 60-70% was prolly a conservative estimate of it happening because I had many people pulled up to me on the street and ask me if something was wrong with the car... or "if it was a diesel" etc. The more and more it happened... the less I would get on the car cause it was embarrassing throwing smoke everywhere.