BMW 325i 2005 misfire

I have a decent CTEK charger so it's on the car now, already reached step 3.

Exposed the battery in the car, the little clear window thingy is red on it as well.

There's nothing I can do but leave it overnight now I guess.

I'm struggling to believe that me having the doors open for a couple of hours could have caused this when it was starting fine yesterday (after having the misfiring on Thursday).

I hope it's not an ECU failure. The dash seemed to go wonky when I tried to start the car, it didn't even get one crank cycle in.
 
danlightbulb said:
I'm struggling to believe that me having the doors open for a couple of hours could have caused this when it was starting fine yesterday (after having the misfiring on Thursday).

I hope it's not an ECU failure. The dash seemed to go wonky when I tried to start the car, it didn't even get one crank cycle in.
Click to expand...
It won't be ECU failure - far more likely it's the battery which can cause all kinds of random issues when old/low.
 
danlightbulb said:
I have never had any issue starting the car before today, even when cold. No indication anything wrong with battery. Car started yesterday when I was looking at the coolant.

Been cleaning it for 2 hrs this morning with the doors open.

Locking still works.

But only 11.3v displayed on the obd device.

I could go get a new one right now from Halfords up the road?

Or I could call out rac?

Man I don't need this stress.
Click to expand...
I've had a battery die on me with no symptoms prior to it dying. It was proper dead as well.
 
@danlightbulb. Is it an N52 or N53 engine? I have the 330i with the N53 engine and caught a misfire.

I replaced spark plugs and coils with didn't cure it and discovered it was injectors which are quite pricey (and difficult to find) for the N53 engine.

My misfire, however was only at start up when the engine was cold and went away in a minute or so.

I would be replacing the battery though, as every one of the three BMW's I've had reacted badly to a degrading battery.
 
Gepetto said:
@danlightbulb. Is it an N52 or N53 engine? I have the 330i with the N53 engine and caught a misfire.

I replaced spark plugs and coils with didn't cure it and discovered it was injectors which are quite pricey (and difficult to find) for the N53 engine.

My misfire, however was only at start up when the engine was cold and went away in a minute or so.

I would be replacing the battery though, as every one of the three BMW's I've had reacted badly to a degrading battery.
Click to expand...

its a N52 pre lci the N53 was plagued with the injector issues.
 
Last edited:
sigma said:
Have you had the car long? A 20 year old 325i is likely to continue to have niggles like this I reckon.
Click to expand...

16 months, bought off a friend when my previous car (Mondeo 2.5T) lunched it's engine. Full service history, regular oil changes etc, water pump done. The spark plugs were changed at the last service before I got the car.

I've since had the cam cover and oil housing gaskets replaced along with new bolts and the fan belt changed, transmission fluid changed with new filter pan, plus a service.

Gepetto said:
@danlightbulb. Is it an N52 or N53 engine? I have the 330i with the N53 engine and caught a misfire.

I replaced spark plugs and coils with didn't cure it and discovered it was injectors which are quite pricey (and difficult to find) for the N53 engine.

My misfire, however was only at start up when the engine was cold and went away in a minute or so.

I would be replacing the battery though, as every one of the three BMW's I've had reacted badly to a degrading battery.
Click to expand...

Yeah n52. The misfire happened on Thursday night a few minutes after starting the car. I could drive the car as long as I kept revs up a bit, it was spluttering at idle. I got home and it was still spluttering. Switched off, ignition off, and restarted and car was ok.

And ok yesterday when I started it whilst looking for fault codes and looking at the coolant (found level to be low, but not enough to trigger a warning).

jeffspuds said:
bump it and go and get the battery tested

bit late today but tomrrow.
Click to expand...

If I can start it tomorrow after charging it, I will go get new battery (if I can drive it). If not, RAC call out.

Then if it appears to be driving ok I will get 6 new ignition coils.
 
Last edited:
OK, it's likely to a one of a number of things.

VANOS solenoid
Fuel injector
Lambda probe
Coil pack
Vacuum leak
Bad MAF (unlikely)

You mentioned it can smoke a bit when cold so my money is on a vacuum leak allowing unmetered air in to the engine.

One thing you can do is disconnect the MAF (do this with the engine off). This will put the engine in to open-loop mode the next time its started. The idle will be higher but it should stop mis-firing. If it does stop then you can discount the coilpack and fuel injector as a possible fault.
Vacuum leak you can test for with a smoke test
Lambda probe will show up in the codes
VANOS solenoid you can test via substitution as they are easy to get to and are cheap.
 
Last edited:
Rilot said:
OK, it's likely to a one of a number of things.

VANOS solenoid
Fuel injector
Lambda probe
Coil pack
Vacuum leak
Bad MAF (unlikely)

You mentioned it can smoke a bit when cold so my money is on a vacuum leak allowing unmetered air in to the engine.

One thing you can do is disconnect the MAF (do this with the engine off). This will put the engine in to open-loop mode the next time its started. The idle will be higher but it should stop mis-firing. If it does stop then you can discount the coilpack and fuel injector as a possible fault.
Vacuum leak you can test for with a smoke test
Lambda probe will show up in the codes
VANOS solenoid you can test via substitution as they are easy to get to and are cheap.
Click to expand...

Thanks the thing is that it already stopped. It happened Thursday night and I was worried about switching the car off in case it would not restart, so I drove home with volatile revs, which was only problematic when idling.

Then when I got home I restarted the car properly and the misfire had gone.

Then Friday and Saturday I restarted the car and it was smooth. I did some maintenance on the car yesterday checking various things and today I cleaned it inside thoroughly. Then it wouldn't start at all so now it's being charged.

There were no codes other than the initial 6 misfire codes.
 
yes , of course it can't be all 6 coils ... & expensive to replace them all speculatively.
I'd still put money on the crank sensor I couldn't get a warm re-start for love or money and had to wait for it to cool, when mine was packing in.

conversely don't see the battery suddenly failing - when mine was weak, did find an hour listening to the radio whilst cleaning car drained it
... can you hear the starter relay clicking nonetheless.
 
jpaul said:
... can you hear the starter relay clicking nonetheless.
Click to expand...

Yes and the engine tried to turn for like half a second then nothing. Also dash has lost the time and date setting.

The car started normally yesterday. All I have done since then is replace one rear bulb, and clean and hoover the inside for a couple hours today.
 
Last edited:
danlightbulb said:
Yes and the engine tried to turn for like half a second then nothing. Also dash has lost the time and date setting.

The car started normally yesterday. All I have done since then is replace one rear bulb, and clean and hoover the inside for a couple hours today.
Click to expand...
Most likely culprit is still the battery I think - could easily have caused the codes for the coils
 
Gepetto said:
@danlightbulb. Is it an N52 or N53 engine? I have the 330i with the N53 engine and caught a misfire.

I replaced spark plugs and coils with didn't cure it and discovered it was injectors which are quite pricey (and difficult to find) for the N53 engine.

My misfire, however was only at start up when the engine was cold and went away in a minute or so.

I would be replacing the battery though, as every one of the three BMW's I've had reacted badly to a degrading battery.
Click to expand...

That sounds like head gasket to me, leaking coolant into the cylinder overnight.
 
Armageus said:
Most likely culprit is still the battery I think - could easily have caused the codes for the coils
Click to expand...

It started. Phew I'm relieved.

Ctek charger had completed its cycle overnight and moved on to maintenance mode. Car fired straight up and drove normally.

So what to do now, get new battery anyway (6 years old)?

bobuk said:
That sounds like head gasket to me, leaking coolant into the cylinder overnight.
Click to expand...

Honestly I'm just not sure. It's cold today (6 degrees) and on my test drive this morning there was some vapour coming out the exhaust. It's not billowing white smoke, just visible vapour that you can see from the mirrors whilst driving.

It has used around half a litre of coolant in six months I'm guessing, assuming they checked it properly when serviced which they might not have.
 
You must log in or register to reply here.
Back
Top Bottom