Smoke under acceleration

[MrBitsy]

I have fitted a Synergy 2 box to my 53 CDT. I am very happy with the performance, but am worried at the amount of smoke being generated.

Initially I had it set to position 2 for medium throttle sensitivity with the MAFAM turned on (I assumed at 49000 miles, my MAF would have some degradation). Performance was great, but under strong acceleration (throttle gradually depressed, warm engine) I can see a lot of diesel smoke.

With the MAFAM section turned off I get the same performance, but still a lot of smoke under acceleration. Also, even when the engine is at operating temperature, I can here a 'pinking sound' under acceleration.

Any comments on why I am seeing so much smoke?

[Greeners]

Have a look on RoverRon's web site......he may list some possibilities there.

[Dave***t]

Forgive me if you've already come across the following, but it doesn't hurt to reiterate.

If you're getting the same performance with the MAFAM turned off, it's likely to mean your MAF is ok and you can leave the section off for the time being. Having it on needlessly can cause extra smoke.

Usual culprits for excess smoke would be dirty EGR (which you can clean, see Ron's site), dirty PCV (which can be cleaned or replaced) and insufficient air (helped by intake mod). I'll be looking into these same things myself over the next couple of months, and reports from members who have done these things are that smoke is greatly reduced.

HTH.

[Roverron]

I have fitted a Synergy 2 box to my 53 CDT. I am very happy with the performance, but am worried at the amount of smoke being generated.

Initially I had it set to position 2 for medium throttle sensitivity with the MAFAM turned on (I assumed at 49000 miles, my MAF would have some degradation). Performance was great, but under strong acceleration (throttle gradually depressed, warm engine) I can see a lot of diesel smoke.

With the MAFAM section turned off I get the same performance, but still a lot of smoke under acceleration. Also, even when the engine is at operating temperature, I can here a 'pinking sound' under acceleration.

Any comments on why I am seeing so much smoke?

Its sounds like not enough air for the amount of fuel as a lot of smoke is unusual and many owners don't get any even on setting 10.

I would recommend fitting an egr bypass or at least cleaning the existing egr valve and also cleaning the pcv valve.

Also do the intake mod 2 which also allows more air in and also prevents any possibilities of spray being ingested and wrecking the maf sensor.

The egr bypass is available from [email protected]

The other details are here:

http://tuning-diesels.com/75Zt/R75serv.htm

Ron

[JohnDotCom]

Changing the PCV reduced my smoke almost to none, after all the other Mods undertaken.
I would still get smoke if heavy acceleration from Cold though.

[MrBitsy]

Thanks for all the suggestions. I have never done any car servicing and do not have any tools either, so have asked Lates about this work. :panic::D

[Roverron]

Thanks for all the suggestions. I have never done any car servicing and do not have any tools either, so have asked Lates about this work. :panic::D

Its never too late to learn if Lates is booked up for weeks!

Haynes do a manual, Argos will sell you an adequate toolkit for under £20 and there's no shortage of helpful souls on here.

Ron

[Greeners]

I'm only round the corner if you need a hand.....

[tapped]

I've got Rons STM 2 kit on my 116.

Tried it at 10 with the mafam on and it just made it feel rough (probably just injector noise) Car runs lovely with the setting at 3 and no Mafam so am assuming that MAF is still o.k. Fuel consumption is great and even on setting 10 with MAFAM on I didn't see any smoke!

Just bought a PCV new anyway cos I am lucky enough to get parts cheap. I'm changing it on the basis that the car has done 83k and this thing runs on treacle so why not eh?

Its an easy job to do PCV and clean the EGR. Be brave! Nothing against Lates at all but save him for the tricky stuff and get your hands dirty ;)

Next stop will be to do the intake mod.

[baxlin]

Changing the PCV Valve reduced my smoke almost to none, after all the other Mods undertaken.
I would still get smoke if heavy acceleration from Cold though.

JDC, forgive me being picky, but when you say you changed the PCV valve, can I assume you just replaced what BMW refer to as the "oil separator", ie what we'd call the filter, or did you replace a bit (lot?) more?

I've cleaned the filter, as I couldn't get a new one locally, but I'm not sure how well I did it...........

Thanks
Malcolm

[JohnDotCom]

Sorry yes your Description is correct one for replacement, got confused with the EGR Valve.
the Part from BMW Spares, Oil Separator, is cheap enough to not warrant Cleaning in my opinion, and I don't personally think you can clean it as well as a replacement one.
The EGR if not bypassed can also be very mucky at that mileage so also may require cleaning to help reduce any smoke.
I am sorry if I appeared to mislead you this was not my Intention and have edited out the "Word" now. :D