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Sixrox Sixrox is offline
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Join Date: Sep 2020
Car: 2007 335i e93
Default Smoking from exhaust still! - 09-05-2020, 05:36 PM

The car is a 2007 335i e93

The old turbo's had significant waste gate rattle and would not build over 11lbs of boost.

I will do a quick timeline. Just to preface this, the car had very very minimal exhaust smoke if any at all.

I already had installed the VRSF 7.5" Intercooler, Charge Pipe, down *****, Inlets. Cobb Exhaust and a Tune. The Tune was placed back at stock for the installation. It is on the base MHD Tune at the moment. It has not been started again.

Step 1 - Replaced Factory Turbos with RB Turbos Stage 2 dual setup. Replaced Oil Pan Gasket. Replaced Oil Filter Gasket. Replaced Valve Cover Gasket. Added BMS Oil Catch Can. Upgraded Spark Plugs. Replaced Coil Packs. Replaced PCV with the RB PCV. Installed a new Flapper. Swapped to Motul 8100 Oil.

Upon Startup, its running perfect. Let it idle for a bit and then take it around the shop and it starts smoking a lot. Pull it back into the shop, check for any oil etc and it looks clean.

Step 2 - Per research and recommendation, ordered BMW Front and rear drain lines. Upon replacement the front turbo looks perfect and the rear turbo was wet inside. The drain lines did not look to have any issues, but replaced them anyway. Noticed what was a kink in the OCC vent hose into the inlets and relocated the OCC and cleared the kink in the hose.

Upon startup, very little smoke and idle and once it starts warming up, again it is smoking just as it was before.

Step 3 - Per research, ordered a full BMW OEM replacement valve cover with new gasket and bolts. Also ordered a new Flapper just in case, and all FCP Euro had in stock was a Vargus PCV, but my mechanic indicated it did not fit, so we put your RB one back in. Again not thinking that was an issue anyway, was simply trying to narrow down options.

Again Upon startup the car is still smoking with no improvement. After reading and reading I see a few items.

1. A Leak Down test. However the n54 mechanic's I have local indicated that given there was no smoke out the exhaust prior to turbo swap this is not likely the issue. Again, more than willing to do the test if needed.

2. If there was a kink in the drain line and oil got into the exhaust. Motul Oil is more difficult to burn off and given I have not driven the car any significant amount we have not given it the chance to burn anything out. The cobb exhaust has no cats and worst case could be down in the muffler?

3. I saw a few posts that said to remove the OCC and then test it. Again, no real details, but it was mentioned.

4. Turbo seal issue? Which should not be an issue with brand new turbos.

5. A foreign object got into the system, the car has not been under boost to hear anything.

5. Put the stock turbos back in and see what happens.

Looking for input, do you think it could simply be oil in the exhaust? or not ran hard or long enough to clean up anything inside?

I know there are a lot of these posts, and I have read them all I think. I have done nearly everything they said and have had no success. Any help would be great!
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ToolMaker335xi ToolMaker335xi is offline
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Posts: 102
Join Date: May 2018
Car: E92 335xi manual
Default 09-28-2020, 12:10 AM

I struggled with smoking under vacuum for a while too after new turbos. Have you considered blocking off the holes to the intake ports and running an external PCV setup.

The RB external setup is what solved my issue. I still get an occasional puff at a stop but no where near as bad as it used to be.

RB 2ís - inlets - dpís - borla mids - cp/bov- stage2LPFP -Hybrid e85_bef
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iminhell1 iminhell1 is offline
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Posts: 343
Join Date: Jul 2015
Car: 2010 135i
Default 09-28-2020, 03:57 AM

95% of the time it's a vacuum leak.
Check/replace all the hoses coming off the vacuum pump. Make sure the large hose on the vacuum pump is secure. Make sure the cover isn't cracked (more a problem with that HPFP add-on thing).

Wastegate rattle may have been from a bad actuator, did you test them? The rear is more prone to failure than the front. If it's leaking, this can cause smoking also, it's another vacuum leak.

2010 135i auto,
2020 mods: Speedtech S366, VTT DBBL, PR Coils, dual 450's, etc
Best stock turbo 1/8 mile: 7.469 @ 98.56, 1.769 60'
Best stock turbo 1/4 mile: 11.480 @ 121.79 1.802 60'
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ToolMaker335xi ToolMaker335xi is offline
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Posts: 102
Join Date: May 2018
Car: E92 335xi manual
Default 10-25-2020, 04:58 PM

Have you solved this issue?

RB 2ís - inlets - dpís - borla mids - cp/bov- stage2LPFP -Hybrid e85_bef
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