[armend195]

Hello

N47n rwd 2012 with 8hp zf auto. Stage 2, egr off, dpf off & downpipe installed, swirl flap delete, complete timing chain change done few months back.
Okay, it’s been driving me nuts. I’ve written posts everywhere, in different groups and forums but not a single reply.
I will describe it as much as possible.
- No error codes. Reading with ISTA all modules come green not a single fault code.
- Sometimes rough idling, sometimes normal
- MAF readings not stable, going from 5 g/s up to 30 g/s every second at idle, if rev up same for example each second it goes 76, 45, 55, 75, 45 each second etc. Un-connect MAF still same drive.
- New MAF BOSCH no change. New MAP no change.
- When driving with cruise control for example at 60 km/h on straight road, calculated engine load goes up and down from 33% then up to 45% then back down, then back up etc without any input, still same straight road, rpm, speed etc.
- Very high fuel consumption. 7.2l/100km in very economical driving.
- Under 2000 rpm, if i floor it or maybe 50% throttle its takes about 2-3 seconds for the boost to build then the rpm’s start rising.
- In slow speeds car usually shifts down to get the power needed.
- Bad throttle response
- Sometimes harsh gear changes, not snappy, like it overrevs.
- Coolant stable at 88 celcius.
- No sticky brakes etc car coasts freely
- Injectors OK, tested, no leaks nothing.
- WOT is good. Plenty of power at high revs.
- Hard startup, and puff of dark-grey smoke 1-2 seconds after turbo spools up.

Any possible ideas? Someone who can point me in right direction?
What should i log to clarify things?
Thanks

[bmwPower99]

Take the tune off and see if everything improves.

[Watsey]

Originally Posted by bmwPower99

Take the tune off and see if everything improves.

The problem with that is he’s had the swirl flaps, EGR, and DPF removed.

An OEM map will be looking for values for all of those and will most likely throw a CEL / ‘limp home’ error as a result.

[Watsey]

armend195 who did the remap ? Was it tuned /optimised on a rolling road ? First port of call would be taking the car back to whoever did the remap.

[armend195]

Originally Posted by Watsey

armend195 who did the remap ? Was it tuned /optimised on a rolling road ? First port of call would be taking the car back to whoever did the remap.

Reputable firm here in Sweden, done many of mine and friends cars.
Thing is the car ran perfectly after remap then these couple of months it started slowly to develop these conditions

[armend195]

Removing map and going back to stock may cause even more problems due to dpf and egr being off, and by doing this i wont be able to pinpoint the source of the problem im having right now

[Watsey]

As you seem to have checked the MAF, MAP, injectors, etc, I’d look at the following :

EGR valve and operation - could it be sticking due to carbon build-up ?

Turbo actuator - the plastic gears in the actuator motor assembly can wear.

Electrical wiring loom and connectors to key sensors - look for signs of split/worn cables or loose connections.

[Eddamoo]

Has the EGR been both software and physically bypassed by using a blanking plate? A fluctuating MAF reading suggests to me that the engine is getting gas from somewhere else sporadically - the EGR most likely, but it could also be the PCV system.

If the EGR hasn't been physically bypassed, you could try doing it yourself. Either remove the vacuum pipe to the actuator (and plug it with something), or make a gasket between the egr cooler and the inlet pipe. I once did this on an old car by cutting an aluminium coke can to shape!

[Watsey]

Originally Posted by Eddamoo

Has the EGR been both software and physically bypassed by using a blanking plate? A fluctuating MAF reading suggests to me that the engine is getting gas from somewhere else sporadically - the EGR most likely, but it could also be the PCV system.

If the EGR hasn't been physically bypassed, you could try doing it yourself. Either remove the vacuum pipe to the actuator (and plug it with something), or make a gasket between the egr cooler and the inlet pipe. I once did this on an old car by cutting an aluminium coke can to shape!

Good point. I forgot that he included "ego off" in the original post. As you say, there could be a leak into the inlet manifold. A well-sealed physical blanking plate would be needed at the junction of the EGR valve outlet where it joins the inlet manifold.

[armend195]

Originally Posted by Eddamoo

Has the EGR been both software and physically bypassed by using a blanking plate? A fluctuating MAF reading suggests to me that the engine is getting gas from somewhere else sporadically - the EGR most likely, but it could also be the PCV system.

If the EGR hasn't been physically bypassed, you could try doing it yourself. Either remove the vacuum pipe to the actuator (and plug it with something), or make a gasket between the egr cooler and the inlet pipe. I once did this on an old car by cutting an aluminium coke can to shape!

Yes, i’m also thinking something in this direction.
Will try plugging the vacuum line.
A EGR blanking plate was ordered a week ago should be here soon, maybe the EGR was stuck slightly open and gasses are passing through.

Also booked in for smoke test this weekend at local mechanic.
Thanks for info, very helpful!

[armend195]

Originally Posted by Watsey

Good point. I forgot that he included "ego off" in the original post. As you say, there could be a leak into the inlet manifold. A well-sealed physical blanking plate would be needed at the junction of the EGR valve outlet where it joins the inlet manifold.

Blanking plate ordered. Will keep thread updated in case other people have similar problems.

Thanks for helping out!

[Amazinjoey]

Originally Posted by armend195

Reputable firm here in Sweden, done many of mine and friends cars.
Thing is the car ran perfectly after remap then these couple of months it started slowly to develop these conditions

There are non reputable firm here in sweden that can tune the N47, all of them are shit and are runnng more or less random ass-tunes from Winols or Alientech marketplace... Return to stock and you will see that it runs better...


Also swirl flaps are needed for bottom end torque

[armend195]

Okay so…
Blanking plate for EGR fitted and still same issue.
So we did a smoke test and found out that there was a leak where the EGR cooler bolts onto the intake pipe into the intake manifold, where this EGR blanking plate was fitted. Where the sensor sits that measures the temperature of the EGR gases that enter the intake.
The leak seems to be on the EGR cooler side where the 2 bolts that connect it to the intake part. No matter how hard you tighten the bolts it doesnt seem to sit flat onto the intake part.
To explain more exactly what im speaking about. The EGR blanking plate sits between the EGR outlet pipe and intake pipe to the intake manifold. Now the 2 bolts on each side dont squeeze the two sides enough so there is a slight leak. Me and my mechanic did som ghetto shit by cutting out a piece of copper and pressing it in to make a tight fit but i believe theres still a slight leak, bur not the same as before. On my way home from the mechanic car felt a quite bit more responsive and the MAF sensor is still fluctuating a little but mot as much as before, so im glad i found the source.

What now?
Ordered EGR delete kit and removing the whole EGR & Cooler assembly and throwing that sh’t far away. Wont have to deal with possible issues in the future with the well-known cooler problems.

[Watsey]

Good to read that you’ve found the source of the problem.

[TurboWeasel]

Originally Posted by Amazinjoey

There are non reputable firm here in sweden that can tune the N47, all of them are shit and are runnng more or less random ass-tunes from Winols or Alientech marketplace... Return to stock and you will see that it runs better...

Also swirl flaps are needed for bottom end torque

Yep. You need to be careful with over driving N47/N57 injectors as it can f'ck the nozzles up, and then this happens to the pistons. Many crap maps cause this problem.