Hesitation on cold start

[fugowitz]

I think you're getting. Under normal circumstances (especially for a Z4), you shouldn't face any cold start hesitation. But for the older Z3, cold start hesitation could be attributed to the vanos seal failing. I believe there're lots of discussion on this on other beemer sites. They say most vanos' seal would failed by 30k Km, due to the inherent material used in making the seal. It was recommended that the seal be changed to the "vitron" type that are sold by web-sellers such as Dr.Vanos and Beisan. I've posted that question under the Vanos tread in this forum, but no body has replied. Any idea?

 

[gcarch]

Hi fugowitz... I ordered and received my new improved vanos seals from Beisan today. Going to have them replaced soon. Hooked up to an analyser and found no fault reports on the vanos (is that conclusive that there's no vanos seal failure?)

Will update after I get them replaced.

 

[fugowitz]

Greetings gcarch.

I read somewhere that the vanos seal failure may not necessarily be detected by fault codes (due to symptoms at start-up & at low RPM). After dismantling the vanos unit, turn it upside-down in fast repetition. If you could feel the internal piston/valve moving up & down, then the seal has definitely failed. Hope you could share your experience after the seal change. (Also, could you share with me the labour cost in changing the seal…..cause I also plan to do a seal change in due course). BTW, you may need to change the top gasket plus the vanos gasket in the process. Best of luck.