1999 BMW E46 318 stuttering when cold

[WEHGuy]

Hi, my car stutters really bad when driven from cold but, is ok when at temperature. There is no engine management light on. Can anyone help? Thanks in advance

[RobCrezz]

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

[WEHGuy]

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

[BIG BAVARIAN]

As rob said above, it could also be a crank or camshaft sensor,although the lack of warning lights is intriguing, make sure the previous owner has not disconnected /disabled them in someway, as yours is the same engine as mine , M43TU 8 Valve, as opposed to the later N42 16 Valve.

[Reload]

WEHGuy said:

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

Mass Air Flow sensor.

Monitors how much air is being taken into the engine to determine how much fuel to inject, when to fire etc.

Is there no service history with it?

[RobCrezz]

WEHGuy said:

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

In the intake pipe just after the airbox you should see an electrical plug, thats where the MAF sensor is. Try unplugging it and see if the car runs any different, if not, then spray some carb cleaner on it, but be very gentle as they are fragile. Check the air filter while you are there, it could be really old and clogged.

Worth giving it an oil/filter and spark plugs change if you dont know when it was last serviced. Could also be the fuel filter being clogged up. Always best to start with the basics.

[WEHGuy]

RobCrezz said:

WEHGuy said:

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

In the intake pipe just after the airbox you should see an electrical plug, thats where the MAF sensor is. Try unplugging it and see if the car runs any different, if not, then spray some carb cleaner on it, but be very gentle as they are fragile. Check the air filter while you are there, it could be really old and clogged.

Worth giving it an oil/filter and spark plugs change if you dont know when it was last serviced. Could also be the fuel filter being clogged up. Always best to start with the basics.

When I unplug the MAF it idles alot more smoothly and it seems to have alot more power. Are they expensive to change?

[RobCrezz]

WEHGuy said:

RobCrezz said:

WEHGuy said:

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

In the intake pipe just after the airbox you should see an electrical plug, thats where the MAF sensor is. Try unplugging it and see if the car runs any different, if not, then spray some carb cleaner on it, but be very gentle as they are fragile. Check the air filter while you are there, it could be really old and clogged.

Worth giving it an oil/filter and spark plugs change if you dont know when it was last serviced. Could also be the fuel filter being clogged up. Always best to start with the basics.

When I unplug the MAF it idles alot more smoothly and it seems to have alot more power. Are they expensive to change?

Yeah brand new they arent normally cheap. Try giving it a clean, might just be dirty. Does sound like its the culprit!

[WEHGuy]

RobCrezz said:

WEHGuy said:

RobCrezz said:

WEHGuy said:

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

In the intake pipe just after the airbox you should see an electrical plug, thats where the MAF sensor is. Try unplugging it and see if the car runs any different, if not, then spray some carb cleaner on it, but be very gentle as they are fragile. Check the air filter while you are there, it could be really old and clogged.

Worth giving it an oil/filter and spark plugs change if you dont know when it was last serviced. Could also be the fuel filter being clogged up. Always best to start with the basics.

When I unplug the MAF it idles alot more smoothly and it seems to have alot more power. Are they expensive to change?

Yeah brand new they arent normally cheap. Try giving it a clean, might just be dirty. Does sound like its the culprit!

I have tried spraying it with WD40 because my mate said it was the same thing mentioned.

[RobCrezz]

WEHGuy said:

RobCrezz said:

WEHGuy said:

RobCrezz said:

WEHGuy said:

RobCrezz said:

Could be many things. When did it last have a service? spark plugs could need changing.

MAF could also be dirty or broken.

What's the MAF? I'm not sure when it was last serviced. I got it for peanuts and have done about 3500 miles in it.

In the intake pipe just after the airbox you should see an electrical plug, thats where the MAF sensor is. Try unplugging it and see if the car runs any different, if not, then spray some carb cleaner on it, but be very gentle as they are fragile. Check the air filter while you are there, it could be really old and clogged.

Worth giving it an oil/filter and spark plugs change if you dont know when it was last serviced. Could also be the fuel filter being clogged up. Always best to start with the basics.

When I unplug the MAF it idles alot more smoothly and it seems to have alot more power. Are they expensive to change?

Yeah brand new they arent normally cheap. Try giving it a clean, might just be dirty. Does sound like its the culprit!

I have tried spraying it with WD40 because my mate said it was the same thing mentioned.

Hmm, I dont think WD40 will have the same effect...

[WEHGuy]

Thanks ROBCREZZ. I got the MAF sensor today and it seems to have done the job. It's not stuttering now and has decent pull throughout the rev range. Here is a beer token if we ever meet.