Rough running

G

goon

Senior member
 Swansea
Had a couple of instances lately with rough running just after start up with the eml and emission lights on and the engine revving itself up and down. Switch off for a few minutes and it was fine although the emission light took a fair while to switch off.
 
It could be a lambda sensor playing up. The EML should go out after three 'healthy' starts. Check for error codes with an OBD II reader and you should have your answer :thumbsup:
 
As Beedub says - coil packs breaking down are common. Symptoms sound similar to mine from a year back which turned out being 2 packs that had given up.



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Code was P1417,and I have to admit the way I shunt vehicles around doesnt help-start/stop from cold with richening valve constant does the car no favours,will have to get in the habit of letting it run a while before stopping engine.
 
Another forum member had the code P1417 = "Port Air Relief Circuit Malfunction" and was diagnosed as

" ....it's a split hose. Apparently it's connected to the hot film air mass meter - see picture. Tried looking for this part online but only US sites seem to sell it. Can't be hard to get one and it's only a few hose clamps to undo to fit one".

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=19842

Hope this helps, but unfortunately the picture is missing :)
 
Actually Ewazix, the P1417 error code was my car a couple of summers ago and the split hose was someone else with a 2.5l and no error code :P Mine resolved with no treatment.
I did have a further episode of the above when I had a tiny pre-cat exhaust blow due to corrosion between the pipes and the cat heat shield (which had come loose). This time the car had got really hot on a track day and on starting it was running roughly and hunting. This cleared with a restart but left this error code and an audible blow. It was all cured easily with a little welding... The code was due to the pre- and post-cat lambda sensors disagreeing with each other due to the holed exhaust between the two. I'd check the lambda sensors. The other guy on the thread from 2010 had a whistle from the MAF so have a listen there too.
I'll be interested to hear what the final diagnosis turns out to be.
 
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