Weird problem: white smoke only when downslope
 

I just bought a chinacharger and after installation, my exhaust is smoking whenever my car is doing boost at downslope.

I am suspecting the following:
- Turbo oil seal is gone (but if it is, why is it only happening on downslope?)
- oil return line below oil level in sump
- not enough diameter of return pipe
- poor engine ventilation causing backpressure in oil sump

My turbo oil return orifice is face down toward oil sump.
Anyone with similar experience?

do a compression test and add an oil restrictor. and let me know if the compression test numbers are bad and if they arent the restrictor will fix your issue....

whenever in boost or vacuum downhill?

Thanks Shlammed, compression numbers looks good, I will have a look at the restrictor.
Hi Braineack, its happens when on throttle and slight boost onwards.

What I wonder is, why is it that the problem happens on downslope?