Engine Acceleration reduces with a mild hissing sound from engine bay

[Salty B.]

Originally Posted by andrewwynn

What scan solution?

I would use foxwell to monitor the cam angles when you get this condition.

A few different things can cause them to not be the angle they should be and there are six different cam angle values that can be tracked with at least foxwell and surely others.

Cam position sensors original? OEM?

Vanos solenoids ever cleaned?

Oil weight factory spec?

I forgot if the m54 had the cage in the middle of the oil filter but I had one fail on an n52 gave similar symptoms.

How many miles? Both our M54 had the intake CPS fail at 132,000 ± 4000 miles just for reference.

The vanos never gave us any problems on either up to 190/205

I've had vanos solenoid fail on n52 at 125

I've seen oil weight mess with vanos on various engines.

No codes present. (I have an Ancel reader which is supposed to read BMW-specific codes).

Prior owner did a vanos rebuild with a kit from ECS, replaced the accelerator pedal (OEM) and DISA valve (Rein) about 20,000mi ago. His spreadsheet also has a "vanos hose" replaced about 40,000mi ago. It has 198,000 on it. No notation of cam pos sensor replacements.

Oil is 5W40 Liquimoly, Mann filter, recently changed. There is a plastic insert that goes into the filter. Now that you mention it, this started after the oil change and filter replacement... all of the prior owner's oil changes used the same oil, every 3,000mi (I have extended that to 5,000mi because $).

[andrewwynn]

Can you read the cam position realtime and can you graph?

[Salty B.]

Originally Posted by andrewwynn

Can you read the cam position realtime and can you graph?

I have no idea how to do that, but I'll see if the code reader can show me once I get the doors put back together.

[andrewwynn]

I know I used the foxwell to do this. I've had similar power loss on n52 motor from the oil filter cage and from dirty vanos solenoid.

Our m54s both had CPS soft fail approximately 130,000 miles. That however presented as engine stall during slow speed throttle.

The hissing suggests CCV?

[Salty B.]

Originally Posted by andrewwynn

I know I used the foxwell to do this. I've had similar power loss on n52 motor from the oil filter cage and from dirty vanos solenoid.

Our m54s both had CPS soft fail approximately 130,000 miles. That however presented as engine stall during slow speed throttle.

The hissing suggests CCV?

No stalling. Power seems as usual, aside from the occasional unintended deceleration blip. Some days it's fine. Once it happened with cruise control on at 70mph but only for a second or two.

CCV was replaced about 30K ago, 2019, with "PCV system w/o-rings" according to maintenance spreadsheet, along with something called "Pilot Mod to CCV" a few months later. Unsure what that means. The hiss is very brief and high-pitched, like a chirp almost, and only on shutdown. Crankcase does not appear to be under pressure if I pull the dipstick or fill cap.

Can the solenoid be cleaned? They're not cheap.

[andrewwynn]

Solenoid can be cleaned. Not a difficult task YouTube will have videos how.


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