[Pjhanna89]

I've got a 2017 320i (b48), 33k miles (8k with me) and 9/10k OCI kept up in its life so far. I'm running an eco map around 220ps for last 3k miles/4 months with no issues until this week.

Car started rough running, idling and vibration diagnosed as a misfire in cylinder 1 at main dealer. Coils swapped and all spark plugs changed and problem remains on cylinder 1.

Dealer is holding on to car for a week or so due to workload, doing compression test and checking injector but wondering if anyone has had similar issue and should expect them to find something sinister?
I'm worried about possibility the map could have contributed to the issue?
Many thanks

[tpoddar]

I hope it isn't a blown piston. Many other tuned b48s have had this issue. What company tune are you running? Any datalogs?

[Pjhanna89]

Originally Posted by tpoddar

I hope it isn't a blown piston. Many other tuned b48s have had this issue. What company tune are you running? Any datalogs?

I'll be honest, I used a reputable local tuning company( don't want to name as I can' t say that's the reason and not an underlying issue with the cat) but I don't know what company they've bought the tune from. Cause or not first time I've had a car flashed and probably overly naive on my part.

[tpoddar]

If the map was only 220hp, your power levels are much lower than most people that have issues with this engine. What kind of fuel were you running? Do let us know when you hear back from the dealer

[Pjhanna89]

Originally Posted by tpoddar

If the map was only 220hp, your power levels are much lower than most people that have issues with this engine. What kind of fuel were you running? Do let us know when you hear back from the dealer

Thanks for the response, I'll update as soon as I know any more. Run on BP ultimate 97 where possible or if no other option occasionally Maxol standard 95.

[tpoddar]

Any update?

[Pjhanna89]

Originally Posted by tpoddar

Any update?

They've had some covid issues so car is still with them however compression test came back strong, I'll have another update from them on Monday.

[Rich76]

If compression check came back good , spark plugs and coils all replaced / swapped around then you need to be looking at the wiring for the coil packs

[Pjhanna89]

Originally Posted by Rich76

If compression check came back good , spark plugs and coils all replaced / swapped around then you need to be looking at the wiring for the coil packs

Thanks for the advice, anything is a help. I feel like it's an issue would have been diagnosed and fixed in a day or two in normal times but with covid and the MOT tests back in full swing here in NI leaving workshops flat out it's taking a lot longer than i'd like. It's made my wife want me to swap to an a6 but joining here has given me lots of ideas running into £££, best driving car I've owned up to this point!

[Pjhanna89]

*Update*
Even though it has passed compression test, its losing compression on cylinder 1 when it's running and heated up so it's engine out to investigate further.

[Armaan]

Originally Posted by Pjhanna89

*Update*
Even though it has passed compression test, its losing compression on cylinder 1 when it's running and heated up so it's engine out to investigate further.

Is it with a dealer?

If so...$$$$$$$$$

[Pjhanna89]

Originally Posted by Armaan

Is it with a dealer?

If so...$$$$$$$$$

it's with an independent I've always used and trust, I'm still expecting a high cost given the labour involved even before whatever the problem is.

[Armaan]

Originally Posted by Pjhanna89

it's with an independent I've always used and trust, I'm still expecting a high cost given the labour involved even before whatever the problem is.

Fair enough. I'd always trust my local independent, hope you solve it soon.

My B48 has been remapped to 240bhp and I think these engines can handle up to 260 without issue, so it seems like bad luck.

Armaan

[E60525d]

Originally Posted by Pjhanna89

*Update*
Even though it has passed compression test, its losing compression on cylinder 1 when it's running and heated up so it's engine out to investigate further.

Sounds strange. Why would it loose compression when engine is warm?

[Rich76]

Did you get to the bottom of this?

[sensible]

Thanks for the heads up. I think I will be leaving my 420i with the manufacturers map. Hop you get it sorted.

[Pjhanna89]

Originally Posted by Rich76

Did you get to the bottom of this?

I've not, hoping to get it back fixed with an explanation next week and will update as soon as I find out. Trust in the car gone though, I've set up a trade in for an octavia VRS dsg and as soon as the 320i is back its going again.

[tpoddar]

Did you find out what caused all this? How did you finally fix it?

[DieterZim]

I started getting a drive train failure a couple of months ago and had a look at the ecu with a cylinder 4 misfire i replaced all the spark plugs and the issue went away for a month or so and got the same issue with the same error code i then replaced all the coils and then the car was fine for a couple of weeks.Same code came back so i replaced the injector and car ran fine for about a week.i did compression test all came back good the car only starts shaking when i come to a stand still then i get the drive train failure but when i am on the high way the car runs fine had a look at the ecu again and got code 140404 detrimental exhaust intermittent and now misfire cylinder 1 & 3 so i want to replace the HPFP and hope that sorts out the issue any Advice?