316i SE "exhaust emission values have deteriorated"

Today the cold weather and constant running of heaters, lights etc made my battery give up and I had to be jump started (with jump leads) after 3 failed attempts at the 100m push and jump start!

Car definately not as energetic as normal and seem to be losing a wee bit of power (but not too bad). Don't appear to have any exhaust problems/noises/rattling etc. The exhaust emission warning light is now constantly illuminated. The car was serviced in September (70,000 miles) and is not due a service for a wee while.

Does anyone know what causes this and what the remedy is?

Thank you.

Realistically, it could be anything.  The term and fault "exhaust emmisions" can be due to anything from over fuelling, running lean, cam and crank sensor faults, O2 sensor faults, PCV and the MAF as above.

You need a diagnostic check done to prove what has actually failed.  Anything else can be guess work.  I know of a local garage in Bridge of Weir that can read the diagnostics for you.

A failed engine breather system (positive crankcase ventilation PCV) valve could hinder easing starting and throw on a warning light.  Could be something simple like a split hose (you would hear a hiss if obvious) or a sludged up hose.  These can be replaced or cleaned easily enough....trouble is finding the fault.

I had my exhaust emissions warning light come on.  I had the light on with an unsteady idle which I took as being a different fault altogether (spark plug, coil pack, sensor) from a PCV. It took BMW to figure out what was wrong and it was a fault in the engine breather system. Page 2 of this post gives more details.

Or...

Could it be that with all the attempted starting from push starting it has flooded the cylinders?  Excess fuel in the cylinders would then not burn properly and casue the engine to emit out of tolerance emissions forcing on the emissions warning light.  A good run to clean out the cylinders might help that.

The cold temp at the moment won't help with the above though....

Anyhoo, HTH

Andrew

Welcome to the world of BMW ownership.  They like throwing little wobblers and putting warning lights on, just to annoy you. 

It all goes pear shaped then you switch it off, leave it for a couple of hours or overnight and then all is well on restarting.

My E39 did this regularly and my E60 threw a wobbler this morning, switch off, switch back on and all is well.

If the warning light is on persistantly then go and get it looked at.

Yip......shes still in one piece and now thankfully a wee bit closer to home.

Snow still bad here but gritters have been out on the main roads so you can get moving about a bit........but no trains.

Very, very cold now. Minus 8 and its only 5.30pm.

 Soooooo cold!!!

Everything working and back to normal thanks.

No warning lights on.

Took me 1/2 hour to dig her out.

Yip....tried to get to work without success as no trains running tho' website said they were.

Walked to station and discovered that there hadn't been a train there since before the snow started yesterday morning. The snow was covering the rails!!

I feel another rant at our (not so) friendly train operator!!!