Exhaust Emission Values Warning Light? 320i 2007

s4ch117 · 21 Aug 2011 at 13:14

Whilst driving today i noticed the exhaust emissions warning light came on the dashboard.

I was wondering if anyone know what the problem could be and how much it may cost to repair.

thanks for the help!!

[TW]Fox · 21 Aug 2011 at 13:17

It could be anything. You will have to get the fault codes read.

pepsilol · 21 Aug 2011 at 16:52

Could be a vacuum leak.

[TW]Fox · 21 Aug 2011 at 17:32

It could be so many things its pointless us guessing - its pretty much the default behaviour on this car if any of the sensors relating to anything in the emissions system finds something wrong.

Read the fault codes.

pepsilol · 21 Aug 2011 at 19:19

Fault codes aren't always accurate.

My emissions light came on once, came back as EGR mass too high, all tests pointed to yes the EGR air mass was too high.

That is what the fault code was, thats as much information DIS was able to give us.

So even with fault codes read, you still won't know the real issue.

The Edge · 21 Aug 2011 at 20:25

pepsilol said:
Fault codes aren't always accurate.

Pretty good place to start though.

Hxc · 21 Aug 2011 at 20:32

pepsilol said:
Fault codes aren't always accurate.

My emissions light came on once, came back as EGR mass too high, all tests pointed to yes the EGR air mass was too high.

That is what the fault code was, thats as much information DIS was able to give us.

So even with fault codes read, you still won't know the real issue.

So er, what do you suggest? We make random guesses?

[TW]Fox · 21 Aug 2011 at 21:29

pepsilol said:
So even with fault codes read, you still won't know the real issue.

Ok, lets just guess.

There is a misfire in cylinder 3 caused by a failing head gasket.

pepsilol · 21 Aug 2011 at 21:41

Been some confusion, just thinking even ahead onces he's read the fault codes as this is the problem I had on the E46. Even with fault codes it was still a problem to diagnose the emissions light.

Absolutely you should start by reading the fault codes, I'm just thinking a bit further than that, thats all. Not saying he shouldn't read the fault codes at all.

[TW]Fox · 21 Aug 2011 at 21:43

The fault codes will tell you exactly why the light is on. It won't tell you the problem, but it will tell you why the light is on and once you know this, you can begin to work out whats wrong.

pepsilol · 21 Aug 2011 at 22:17

[TW]Fox;19885003 said:
The fault codes will tell you exactly why the light is on. It won't tell you the problem, but it will tell you why the light is on and once you know this, you can begin to work out whats wrong.

Indeed, it can be the start of a very painful process.

However some diagnostic kits, well good ones, will automatically tell you which specific part is wrong and also provide you with the part number.

I say some, only DIS will do this in the BMW case.