Z4 3.0si N52 (facelift) hissing / performance issues

[Marlon]

I have the same sound on very light acceleration but no petrol smell.

I just thought as the tech guy that it was a common thing.

I think you have to have good hearing as I keep trying to get other people to hear it and they never can, I think some think I've gone crazy!

I’m happy to inform that both the hissing and performance issues have gone as a result of removing the mani and replacing the Secondary DISA and CVV. As you can see from the pictures I posted a few replies up, the hissing was most likely caused by the disintegrated DISA seal.

Case closed!

Result - impressive work

 

[ph001]

Good man. Love a good diy fix. I wonder if the later black top engines are any different in these areas?

 

[1doohan]

Love a happy ending....but that's another story

 

[Smartbear]

Good man. Love a good diy fix. I wonder if the later black top engines are any different in these areas?

Hi, when you say black top engines do you mean the plastic cover which sits on top of the cam cover or the cam cover itself?
The different colour plastic covers don’t signify any differences themselves but engines with black cam covers have an integrated ccv instead of the remote item below the inlet manifold fitted to engines with the earlier metal cam covers
Rob

 

[ph001]

Yeh, that’s what I meant. I seemed to remember something about the ccv being different - thanks. I know they have a different dme as well (faster cpu) but I bet the map is the same.

 

[WouterZZZZ]

Thanks for the guideline and advises above in solving the hissing sound during acceleration. N52 Z4 3.0si from september 2006, low mileage. We replaced the full CCV and the smaller DISA. You can clearly see the differences between the old (various parts of the rubber gone and oil on it) and the new. The oil separator and all tubes also replaced. Hissing sound fully gone, driving like a charm.

 

[WouterZZZZ]

In addition: the petrol smell during start-up, has also gone!

 

[LBN]

Glad I found this thread, my E86 has just started making a bit of a hissing noise. Hopefully it’s just some perished rubber that’s easy to get to, don’t fancy taking the inlet manifold off