lites flicker and rough idle - BMW Forum

STEPHEN WILKERSON · 06-08-2009, 04:04 AM

ran good until now got check engine lite then it stalled. wont restart and error code read 1223 coolent sensor can the sensor failing prevent engine from starting.didnt overheat and only problem has been the flickering of the lights and a rough idle

marti5 · 06-08-2009, 07:32 AM

It can in some cases as it sends a message to the ECU not to start to protect the engine.

STEPHEN WILKERSON · 06-08-2009, 07:50 AM

Thanks For The Info.....i Did Notice A Split In The Intake Boot And The Spark Plugs Show Heavy Carbon Deposits Running Rich I Guess The Coolent Sensor Is Controling The Fuel Mixture And Injector Duration That Split Could Be Part Of My Idle Prob Right?

STEPHEN WILKERSON · 06-08-2009, 07:53 AM

What Are Some Of The Not So Common Prob That Would Make The Flicker Of The Lites

marti5 · 06-08-2009, 08:27 AM

Low Battery voltage for flickering lights may be the cause it may also be a loose belt or your alternator is faulty, get the intake boot sorted this will help to sorting out your idle problem, clean the plugs or replace as you say they are carboned up and change the coolant sensor.

STEPHEN WILKERSON · 06-11-2009, 06:35 PM

Fixed .....replaced Coolent Sensor Got Car Running Replaced Sparkplugs New Intake Gasket{old One Ate It On Removing Manoifold}.......also Got New Alt Belt ...........battery Is New.... Lites Still Flicker So Need To Check Alt..........idle Still Seems Rough. What Is The Gap On Plat Plugs One Elec.32?............next Will Check Other Sensors That May Infulience Idle Then Fuel Pressure.............. Injectors And Fuel Filter........am I On The Right Track?....
The Idle Is Fine When Running And In Park But In The Other Gears Rough Could Low Trany Fuild In An Automatic Cause This?

84bmw318i · 06-11-2009, 11:24 PM

mine did the same thing and it turned out to be the alternator went bad

newbie77 · 09-22-2009, 06:53 PM

Hi All,
I'm learning about cars at the moment so forgive me if I'm repeating a frequently asked question.

My 92 316i has flickering headlights/dash (which went out tonight for extended periods) and interior lights. The idle is also very erratic and the car seems to "stutter" at low speeds (30-60kmph).

I read on this thread that it could be the voltage regulator then a mechanic told me (without looking) that my model of car doesn't have a voltage regulator. Is this the case?

Either way, has this happened anyone else and what is the cause? The battery or Engine light isn't on constantly or anything, just a general flickering and now the dash comes and goes.

Any and all advice greatly appreciated.

Paul

bimmerfeel · 09-22-2009, 11:55 PM

these cars use high-energy ignition systems. so an alternator that is dying tends to cause problematic electronic behavior; erratic idle, stutter, flickering lights. Other causes of idle/performance can include vacuum leaks and/or fuel delivery issues. But the flickering lights is sort of giving it away here. And yes, the system is internally regulated by the alternator itself and does not use a voltage regulator(external).

newbie77 · 09-23-2009, 03:23 AM

Thanks Bimmerfeel, I was afraid someone was going to say that. I'll have it checked today.
Is this something that could just completely go as I am driving and leave me stranded?

newbie77 · 09-23-2009, 03:40 AM

Oh, I'm just going to throw this into the diagnostic mix in case there's a link ok?
The heater only works on setting 4, not on 1,2, or 3. Is that totally a different issue?
Thanks everyone.
Paul

CanadianWraith · 09-23-2009, 08:18 AM

yes, check your final stage unit

newbie77 · 09-23-2009, 08:20 AM

I popped around to my local mechanic this morning and he thinks it sounds more like a connection and that if the alternator was dying the battery light would be on constantly and there would be starting difficulties.
He thinks the idle is unrelated. And the heater issue is unrelated. mmmm

bimmerfeel · 09-23-2009, 02:14 PM

alright, if it's something else electrically, fine. nothing like being there to diagnose it properly.

running/idling poorly can most often be traced to vacuum leaks, on the otherhand. get a can of quik start(any brand) and spray around the intake bellows to see if the engine speeds up; if it does you have a vacuum leak at that location.(engine reacts to the quikstart as a fuel and momentarily increases power output..). or a good visual check and tighten all hose clamps and manifold connection bolts that you can see may help.

the heater issue is coincidental to all of this. you need a resistor pack, part no. 64118391749 I believe.