Hi all,
Here is the background story that led me to replace the Vanos unit in my S50 powered -99 Coupe : http://www.z3mcoupe.com/forum/showthread.php?t=17316
Here some earlier analysis and attempt to summarize the Vanos procedure before I actually pulled that damn thing out myself : http://www.z3mcoupe.com/forum/showpo...82&postcount=9
I have now done some practical work with my car and the story in figures can be found here : http://v2tre.wordpress.com/2014/12/2...uns-perfectly/
In short I have :
- replaced all relevant vacuum lines that are the normal suspects for rough idle
- replaced the complete Vanos unit with a Rolls Royce factory serviced unit
- adjusted the valve clearances
- changed camshaft position sensors
- changed plugs, oil and filters
The happy outcome was that now the car idles perfectly, pulls smoothly from the idle upwards, the Vanos is much quieter than earlier and the engine seems also to be happier in higher revs.
I have owned the car from 67 tkm upwards and at idle there has always been a slight "pop" sound from the exhaust every 5 or so seconds. In addition, the engine shaked shortly every now and then when stopping at lights. It felt like the engine would have a single misfire every 5-10 seconds. Otherwise the engine worked ok and has full power. During last summer the engine first started to run roughly for about 5 seconds after a cold start. Then towards the end of the summer it did not idle any more correctly under 900 rpm. From that upward it worked ok.
Now all this seems to be history and especially the low rpm end seems to be smoother that ever :)
If there is interest, I can try to walk you through of some of the things I noticed when doing these service steps. These notes might fill in some things that at least to me were not fully clear after reading through the Beisan procedures and the BMW TIS procedures.
br, Juhav
Here is the background story that led me to replace the Vanos unit in my S50 powered -99 Coupe : http://www.z3mcoupe.com/forum/showthread.php?t=17316
Here some earlier analysis and attempt to summarize the Vanos procedure before I actually pulled that damn thing out myself : http://www.z3mcoupe.com/forum/showpo...82&postcount=9
I have now done some practical work with my car and the story in figures can be found here : http://v2tre.wordpress.com/2014/12/2...uns-perfectly/
In short I have :
- replaced all relevant vacuum lines that are the normal suspects for rough idle
- replaced the complete Vanos unit with a Rolls Royce factory serviced unit
- adjusted the valve clearances
- changed camshaft position sensors
- changed plugs, oil and filters
The happy outcome was that now the car idles perfectly, pulls smoothly from the idle upwards, the Vanos is much quieter than earlier and the engine seems also to be happier in higher revs.
I have owned the car from 67 tkm upwards and at idle there has always been a slight "pop" sound from the exhaust every 5 or so seconds. In addition, the engine shaked shortly every now and then when stopping at lights. It felt like the engine would have a single misfire every 5-10 seconds. Otherwise the engine worked ok and has full power. During last summer the engine first started to run roughly for about 5 seconds after a cold start. Then towards the end of the summer it did not idle any more correctly under 900 rpm. From that upward it worked ok.
Now all this seems to be history and especially the low rpm end seems to be smoother that ever :)
If there is interest, I can try to walk you through of some of the things I noticed when doing these service steps. These notes might fill in some things that at least to me were not fully clear after reading through the Beisan procedures and the BMW TIS procedures.
br, Juhav
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