Blue smoke on extended idle. 2006 4.8is.

[A B Able Truck]

The carbon build up on the piston tops was a big problem. That is what raised my HCs and caused excessive water.

[Porschesolutions]

Ok: no disconnecty the harness

I thought there was a breather pump besides the CCV to help scavenge oil & vapor from infiltrating the intake.

[A B Able Truck]

Originally Posted by Porschesolutions

Ok: no disconnecty the harness

I thought there was a breather pump besides the CCV to help scavenge oil & vapor from infiltrating the intake.

** Not on mine & I haven't run across any liturature that indicates that. The older N62s had a secondary air pump that injected air before the cat for unburned fuel. The CCV systems are basic.

[pcb5]

Ok, so what years have the air pump?

[pcb5]

I'm getting secondary air pump codes for bank 1&2. I clear the codes, after its warmed up and they stay cleared til the car sits over night.

[A B Able Truck]

Originally Posted by pcb5

Ok, so what years have the air pump?

Bentley says:
5 series V8 engine models manufactured to 03/2005 (545i)

[pcb5]

Originally Posted by A B Able Truck

The carbon build up on the piston tops was a big problem. That is what raised my HCs and caused excessive water.

Please explain HC's and why carbon build up would cause excessive water?

[A B Able Truck]

Originally Posted by pcb5

I'm getting secondary air pump codes for bank 1&2. I clear the codes, after its warmed up and they stay cleared til the car sits over night.

Here is a SIB on the issue:
http://www.m5board.com/vbulletin/att...-sib110504.pdf

I have read that there is a tool offered from a repair shop in my area that cleans the ports out (somewhat) without pulling the heads.
(I think it's All German Auto in Escondido CA. - try utube)

[A B Able Truck]

Originally Posted by pcb5

Please explain HC's and why carbon build up would cause excessive water?

I'm not a chemist or a smog tech - my smog tech buddy told me but it hasn't sunk in yet. I did run across a colorful tech manual with lots of great detail which I'll try to find. In the meantime here is an Emissions Manual with lots of reading and it covers the secondary air pump.

http://prodcds.bmwuniversity.com/lib...Management.pdf

[TerminatorX5]

here is some info i found in WDS:

Idle speed control




The idle speed control valve is designed as a non-wearing two-winding rotary actuator. The rotary slide valve in the idle speed control valve may only be tested by way of activation via a tester or by shaking. Moving the rotary slide valve with the finger or with a tool such as a screwdriver is not permitted. This would mean that the rotary slide valve would no longer function correctly.
The idle speed control valve is now responsible for several tasks and is therefore an important component in the intake air tract of the engine.
Small air leaks which may occur, for example, at leaking gaiters/cylinders or in the event of a varying gap in the throttle valve can be compensated up to a certain extent by the idle speed control valve.
The idle speed control valve opens a little more during the engine coasting phase and closes just before reaching idle speed. This prevents a high intake pipe vacuum and blue smoke emission (oil vapour via valve stem seals).
During engine start, the idle speed control valve enables an opening cross section that is above that of idle speed. This ensures the engine starts more efficiently.
The idle speed control valve features an emergency operation opening gap which ensures certain emergency running functions in the event of power failure.