My bmw 116i is running rough, seems to be off a cylinder?

what fuel?, gas or diesel, LPG, LNG, e100 what?
(E81/E82/E87/E88; ? aka E8x says
"the four-cylinder turbo-diesel, four-cylinder naturally aspirated petrol, six-cylinder naturally aspirated petrol and six-cylinder turbocharged petrol (the latter only available on coup? and convertible models)."
I can not guess engines !, if not told straight up."
what does 1116i mean., google returns zip, a typo or bounced a key? YES !
or post the country and VIN and we tell you what is under the hood
and is first, step.
let we wild guess it burns GASoline (petrol)
and has spark (sure does) and spark is dead
DIY.
all fuses good
and next we scan the car at the OBD1 scan port USA, 16pins.
it then tells my why spark is dead.
and why spray test fuel fails. a standard easy test, for prove spark and engine are ok for 100 years, the same exact test.

your engine is here. find it and tell it for 10x more exact answers for free.

https://en.wikipedia.org/wiki/List_of_BMW_engines


OK googling me like crazy car really is
Series 1.6 116i just 2 ones. no three.
I guess this is a BMW test day?
best I can tell that is an E87 BMW,actual
E87 1 Series 5 door 116i has a naturally-aspirated Inline 4 cylinder engine, Petrol motor. 1596 cm3 (1.6l)
This engine produces a maximum power of 115 PS (113 bhp - 85 kW) at 6000 rpm and a maximum torque of 150 Nm (110 lb.ft) at 4300 rpm.

So if E87 it is then it has spark and no fuel ever burns lacking spark
and must be scanned, after all fuses test good
here is the best test (EFI ways) DYI
1: connect scan tool & key on make sure scan tool works.!!!
2 CRANK FOR 5 SECONDS, AND RELEASE KEY
3: DO NOT TURN KEY OFF NOW.
4: SCAN AGAIN SEE WHY ECU TELLS YOU WHY SPARK IS DEAD,
IT SURE WILL, DTC P-3XX , HARD HARD ERRORS. LIKE THESE.
CPM DEAD.
CKP DEAD
SPARK DEAD.
FUSES DEAD
BATTERY WEAK.
AND MORE, NOT SCANNING IS THE PROBLEM
YOU CAN NOT FIX MODERN CARS LACKING THE TOOL SO RENT ONE/?

MY GUESS THIS IS THE CAR

https://www.ultimatespecs.com/car-specs/BMW/4921/BMW-E87-1-Series-5-door-116i.html

have the cylinders compression tested , may have a faulty piston,valve,rings

running rough something failing smoke something failed

Try this YouTube link. It is for an E87. BMW 1 Series E87 fuel filter replacement maintenance service

no voltage

could be battery flat or loose terminals
alternator
start motor
engine bay fuses or relays

next to check os immobiliser

if you cant sort it .. may need a tow to the bmw service center

does the car seem to run roughly? sounds like a possible head gasket or a cracked cylinder. is there an unusual amount of moisture coming out of the exhaust pipe, would smell like antifreeze gaseous sweet smell. a crack will fill either the top of a given cylinder but only when the engine is not running. head gasket will dump water into the oil giving it a milky look also will be prone to overheating

0W40 SYNTETIC .0W30 SYNTETIC- BMW LONG LIFE 01,04,FE, ACEA A1 0W30. 4.25 L

Kindly check these links and download the manual:

http://www.pdfoo.com/result--bmw-116i-user-manual.html

http://www.pdf-word.net/Automotive-Guide-BMW/The-BMW-1-Series-116i.html

Dirty injectors.add fuel additive to fuel tank.Buy a good brand of additive

Tere should be an automatic service light that comes on when you turn the key. How many miles are on the clock and when was the last service?