[TheGoodTheBadTheUgly]

Okay here is the deal. Over the past 4 months, it occurred 3 times that my car went into limp mode ("iDrive showing Engine Malfunction: Reduced Power"). The IATs seem to indicate 80 Celcius (176 Fahrenheit) at some instances.


The main codes are:

29E4 - Charge air temperature, plausibility: Temperature too high.


And this code causes:

2C58 - Charging pressure control: Switch-off as consequence (Cuts boost)


There is also a bunch of shadow codes related to MAP sensor.

2904, 2908, 29E7: Charge-air temperature sensor: Mutliple fault.


This brings me to diagnosing. I have an ETS 7" FMIC on the car and I highly doubt that the FMIC is the problem. First off, the boost curve is on par with target and my numbers are excellent meaning there is no leak. So the FMIC seems to be working fine. It's a simple machine and the only thing that could affect it's performance is if it's damaged or clogged and it appears to be pretty clean for the moment. I can't think of anything else regarding the FMIC.

Next thing is the MAP sensor. I would of hoped that it is the sensor going crazy, but somethings aren't pointing in that direction. At cold start, the temperature outputted by the MAP sensor is very close to ambient which makes me think that the sensor isn't necessarily going crazy.

Finally, Exhaust temps. My exhaust temps are sitting between 1450 and 1550 Fahrenheit or 750-830 Celsius. These don't dangerously too high, but if they were too high and for some long time, it could easily transfer it's heat from the turbine to the compressor by overpowering the isolation around the center housing rotating assembly. This would then obviously affect the temperature of the IATs.

Another thing to note is that I am running MHD Stage 1+ and with GFB DV+ with main spring installed so I achieve higher boost peaks than usual, but I am not sure if this is enough to make me reach such high temps.

I will include a long log of me driving back after the Limp mode went away. It is not a proper log but there are good chunks of info in there.

So I am kind of loss about what to do and I don't know quite sure what I should be looking for. I might try to change the sensor and see if that helps with anything, but I would happily accept all suggestion and help.

https://datazap.me/u/thegoodthebadth...og=0&data=4-20

[type-dRew]

Yeah id just replace the TMAP and see what happens. Too much points to the sensor itself to believe anything else before that gets changed. Its also easy and cheap to replace.

[Supermoon]

Put the stock intake back in. You have a hot air intake.

[TheGoodTheBadTheUgly]

Originally Posted by Supermoon

Put the stock intake back in. You have a hot air intake.

That's a good point. I also have to clean my filter. But look at everyone with BMS or Injen intake. They get hotter than OEM closed filter but no one gets this issue.

You are running an Injen Intake which is almost the same the BMS and a tune that is probably more aggressive than mine based on all your mods. Did this ever happen to you?

[TheGoodTheBadTheUgly]

Originally Posted by Supermoon

You're looking at one right now. I get the same code.

Interesting. I just finished putting the stock intake back and I will clean my dirty ass BMS filter meanwhile. I'll drive for a bit of time with stock intake and see if there is any difference. I am sure there will be.

[Tiago@VRSF]

Intake has nothing to do with this, it sounds like your FMIC may not be capable of supporting the demands of your existing tune/boost level.

I'd recommend replacing the intercooler with a brand that has evolved their product line to meet the ever changing needs of this platform

To give you an idea, we have changed our standard 7" FMIC 5 times over the past decade to suit the continually changing market demands. Our original 7" was replaced with our 7" HD in 2016 (held the record for the highest HP stock turbo N54 along with the fastest stock turbo N54) and was then replaced by our 7.5" Competition HD in 2018 (proven to support up to 850whp).

[TheGoodTheBadTheUgly]

Originally Posted by Tiago@VRSF

Intake has nothing to do with this, it sounds like your FMIC may not be capable of supporting the demands of your existing tune/boost level.

I'd recommend replacing the intercooler with a brand that has evolved their product line to meet the ever changing needs of this platform

To give you an idea, we have changed our standard 7" FMIC 5 times over the past decade to suit the continually changing market demands. Our original 7" was replaced with our 7" HD in 2016 (held the record for the highest HP stock turbo N54 along with the fastest stock turbo N54) and was then replaced by our 7.5" Competition HD in 2018 (proven to support up to 850whp).

I am sorry but I have to disagree with you.

I respect your company and the insane evolution it went through in such short time. I even bought a downpipe from guys because I believe in you products, but telling me a FMIC from ETS with proper size is not able to pull through MHD Stage 1+ is non sense.

You are probably one of the ones who knows the most how simple a intercooler is. My stock intercooler could probably had of pulled a better job than the numbers I am seing. So I highly doubt that it is the FMIC.

Now telling me a 7" FMIC from ETS isn't enough to withstand MHD Stage 1+ is far fetched considering it is one of the best cooler with the one from ER on the market. People even use the 5" from ETS for tunes far more agressive.

I don't know if you realise but it is quite unepleasant to receive that kind of reply. Please go do you marketing elsewhere, not somewhere where someone needs help and you are litteraly suggesting to swap his FMIC for one of your products that will do the exact same thing.

[Pladi]

Originally Posted by Tiago@VRSF

Intake has nothing to do with this, it sounds like your FMIC may not be capable of supporting the demands of your existing tune/boost level.

I'd recommend replacing the intercooler with a brand that has evolved their product line to meet the ever changing needs of this platform

To give you an idea, we have changed our standard 7" FMIC 5 times over the past decade to suit the continually changing market demands. Our original 7" was replaced with our 7" HD in 2016 (held the record for the highest HP stock turbo N54 along with the fastest stock turbo N54) and was then replaced by our 7.5" Competition HD in 2018 (proven to support up to 850whp).

This type of marketing strategy tends to backfire. Trust me you have lost me as a customer for sure.

[RoughKnight]

He's just hurting for sales
Back on topic please, I would like to know if there are any other answers or solutions as I am experiencing some of his symptoms.

[TheMidnightNarwhal]

Originally Posted by Tiago@VRSF

Intake has nothing to do with this, it sounds like your FMIC may not be capable of supporting the demands of your existing tune/boost level.

I'd recommend replacing the intercooler with a brand that has evolved their product line to meet the ever changing needs of this platform

To give you an idea, we have changed our standard 7" FMIC 5 times over the past decade to suit the continually changing market demands. Our original 7" was replaced with our 7" HD in 2016 (held the record for the highest HP stock turbo N54 along with the fastest stock turbo N54) and was then replaced by our 7.5" Competition HD in 2018 (proven to support up to 850whp).

Dude he already has a upgraded 7" FMIC. No way this would allow his temps to go up to 80c on Stage 1+ lol.

[TheGoodTheBadTheUgly]

Originally Posted by RoughKnight

He's just hurting for sales
Back on topic please, I would like to know if there are any other answers or solutions as I am experiencing some of his symptoms.

O nice you are in Ottawa!

So a quick update on the situation. I swapped to the stock air intake and I've got to admit that I think Tiago was right on this one. It doesn't seem to be the intake system. My IATs are still pretty high and most importantly they do not go down during a pull, but rather up.

I guess sensor is up next?

[E92-Ghandi]

I had a smilier issue, IAT's jumping around, it turned out to be the TMAP sensor.
Upgraded the TMAP with N20 and everything is back to normal.

[TheGoodTheBadTheUgly]

Originally Posted by E92-Ghandi

I had a smilier issue, IAT's jumping around, it turned out to be the TMAP sensor.
Upgraded the TMAP with N20 and everything is back to normal.

Yeah you are not the first one who is suggesting to go with the n20. I got told the N20 is even good above 20 Psi?

[Supermoon]

Originally Posted by TheGoodTheBadTheUgly

Yeah you are not the first one who is suggesting to go with the n20. I got told the N20 is even good above 20 Psi?

I think your TMAP sensor is dirty or faulty.
3.5 bar TMAP sensor is worth getting if you need a new sensor for future purposes but it's not plug and play for harness A (MY2011) so you need an adaptor from BMS or harness B connector & repin if you're ok with permanent modification.
Also you might want to have extra o-rings for the TMAP sensor before pulling out the old one. I ripped mine and it wasn't available separately from BMW so I ended up getting Buna-N o-rings from hardware store.
You want ID 10mm, OD 14mm Viton or Buna-N.

[bbnks2]

It takes all of 2 minutes to pull the TMAP out of the charge-pipe and clean it off with some brake clean. Try that.

That log looks like you were beating on the car hard for 10 minutes straight? Can't really tell much from it... but it's plausible you are just heat soaking the crap out of the car by doing pulls on the street. I see a few 5th gear pulls in there. What was ambient temp in this log?

Can you post a straight 4th gear pull from 3k-6.5k and keep track of what ambient it is pulled in?

[Bullcitybmmer]

Originally Posted by bbnks2

It takes all of 2 minutes to pull the TMAP out of the charge-pipe and clean it off with some brake clean. Try that.

This. Go get some MAF cleaner, clean the TMAP, it's an easy troubleshoot that might fix the issue. Heck, while you're at it, clean the manifold MAP sensor & MAF sensor while you're taking stuff apart just to make sure they're in top shape.

You might also want to try swapping the MAP sensors, to see if that changes anything. They do different jobs, but it's the same part #. If that changes the trends in your logs, it's probably an indication that one of them is bad.

[TheMidnightNarwhal]

Originally Posted by Bullcitybmmer

Heck, while you're at it, clean the manifold MAP sensor & MAF sensor while you're taking stuff apart just to make sure they're in top shape.

You might also want to try swapping the MAP sensors, to see if that changes anything. They do different jobs, but it's the same part #. If that changes the trends in your logs, it's probably an indication that one of them is bad.

Wait what? N55 only has one TMAP and one MAF.

N54 has one MAP and one TMAP. They are not the same part numbers they are pinned differently on the connector.

[bbnks2]

Originally Posted by TheMidnightNarwhal

Wait what? N55 only has one TMAP and one MAF.

N54 has one MAP and one TMAP. They are not the same part numbers they are pinned differently on the connector.

N55 has three sensors and the DME codes can be confusing as to which it is throwing an error for.

* MAF is on the air intake.
* TMAP is in the charge-pipe (T for temperature)
* MAP is in the intake manifold.

The MAP and TMAP can be interchanged I believe. The idea being that the DME will throw different codes if you swap the sensors and the sensor is the issue.

[TheMidnightNarwhal]

Originally Posted by bbnks2

N55 has three sensors and the DME codes can be confusing as to which it is throwing an error for.

* MAF is on the air intake.
* TMAP is in the charge-pipe (T for temperature)
* MAP is in the intake manifold.

The MAP and TMAP can be interchanged I believe. The idea being that the DME will throw different codes if you swap the sensors and the sensor is the issue.

Oh you're right there is one on manifold to I see on RealOEM. Why are there 2?

But the part numbers are the same for both so that means they are both TMAPs then.

[bbnks2]

Originally Posted by TheMidnightNarwhal

Oh you're right there is one on manifold to I see on RealOEM. Why are there 2?

But the part numbers are the same for both so that means they are both TMAPs then.

Parts numbers are the same so, yes, they can both serve the purpose of reading temperature. However, they both don't function as TMAP sensors. One is reading post throttle manifold pressure and the other is reading pre throttle intake pressure and temperature. The data from both sensors is used for all sorts of various dme logic.

[TheMidnightNarwhal]

Originally Posted by bbnks2

Parts numbers are the same so, yes, they can both serve the purpose of reading temperature. However, they both don't function as TMAP sensors. One is reading post throttle manifold pressure and the other is reading pre throttle intake pressure and temperature. The data from both sensors is used for all sorts of various dme logic.

Ok so they are both technically TMAPs but the car don't use both as TMAPS. I was confused because on N54 they have one as TMAP and other as MAP (different PNs). I guess they said F it and just make them both TMAPs on the N55 to avoid confusion.

[TheGoodTheBadTheUgly]

bbnks2

I will clean the sensor today. I will also try to get a proper log to upload for you, but meanwhile, I have this one that I took yesterday after switching the air intake. Note that the engine bay was not 100% cooled and at rest, meaning IATs start high so this is why it's not an excellent log for reference.

https://datazap.me/u/thegoodthebadth...&zoom=874-1188

Ambient temperatures were around 25 Celcius when I took the log.

I have to be honest with you guys, I use my car a lot and do many frequent stops during the day where the car is turned off and sits for a bit. Between driving to university, job and groceries it is normal that the IATs go up a lot. I was really wondering for a lot of time before posting on here if I am just paranoid and it's simple to heat soaking, but I couldn't believe that it never occurred to anyone else.

As well, if anyone knows how I can ventilate this damn engine bay that gets hotter than dragon breath please let me know.