Nightmare diagnosing n54

[iminhell1]

Start shopping for a LS and adapter mounts.

 

[iminhell1]

Also,

 

[Msport335]

They are new index 12s and the rough idle is not from a leaky injector...those feel like irratic hiccups which sometimes trigger misfire codes. This rough idle is different and sounds in line with the compression stroke of the motor. No white smoke out the exhaust...just coming out the oil cap when I open it and some out of the catch can vta side

 

[iminhell1]

Depending on pressure and amount, that tends to be a cracked ring.
Compression test should reflect/confirm this. You should see one cylinder down quite a bit vs the others. Lets say a 20% difference in 1 cylinder. So if you have 5 at 190 (which is what you should be near) then 20% loss you should see one around 150, or lower.
But with the sound you describe I would think you'll see one below 100psi.

 

[Heyfred]

If it was a cracked plug wouldn't it throw misfire? The rough idle is also not from a bad injector... it sounds like its got a high lift/duration cam in it now

Big cam sensation = Vanos sticking.

 

[Msport335]

How do I post a video here... it doesn't accept mp4?

 

[Msport335]

Hope this works

 

[iminhell1]

Totally normal smoke.
I don't head anything that sounds bad either. No big cam sound and normal sewing machine injector ticking.

So whatever you have going on is intermittent. That rules out anything piston related.
Might be vanos related, but that should throw a cam position error.

 

[Msport335]

You can hear what sounds like the big cam at the back of the car out the exhaust. The idle while sitting in car sounds lumpy...something is up. This smoke only started a few days ago so I wouldn't consider it normal. Definitely smells when driving around now too

 

[S54ca]

You can hear what sounds like the big cam at the back of the car out the exhaust. The idle while sitting in car sounds lumpy...something is up. This smoke only started a few days ago so I wouldn't consider it normal. Definitely smells when driving around now too

The oil vapor venting from the cap appears excessive. Compression or leak down test should be the next step, IMO.

 

[Heyfred]

What PCV system are you running?

 

[Msport335]

What PCV system are you running?

Rb upgraded pcv valve and a bms catch can vent to air

 

[Heyfred]

Is the PCV valve internal or external hooked up to the catch can?

 

[Heyfred]

Unplug the map sensor to if the engine idle changes.

 

[Msport335]

Is the PCV valve internal or external hooked up to the catch can?

pcv valve is in the factory location (within valve cover)

 

[Heyfred]

What Milan said: Vacuum leak. For test purposes, remove the IN hose to the catch can, plug it off and see what happens.

 

[Msport335]

Well, just ran a compression test. Cylinders 1-5 are 180psi and cyl 6 is 90psi. Fml

 

[Heyfred]

Think simple, Walnut blast time. Valve may be stuck open.

 

[Msport335]

Think simple, Walnut blast time. Valve may be stuck open.

Didn't check that long ago and valves were not bad at all. Spraying meth definitely helps

 

[fmorelli]

Well, just ran a compression test. Cylinders 1-5 are 180psi and cyl 6 is 90psi. Fml

Did you test the cylinder more than once?