I haven't looked at how to remove the intake manifold but were it my car I would first look with the inspection camera (using the mirror at end option as well) and fish around with a magnet. If I couldn't find the pin I would google hoe to replace seal on intake manifold and open it up.

My understanding is the steel pin can get in the way of an intake valve seating and really cause bad damage. You could detect that damage by measuring the compression of each cylinder I suspect.


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Just a PSA... a friend over on the ZHP board lost a Torx bit; it lodged in the intake... for a while. It eventually freed itself and got sucked into and destroyed #6 cylinder. The pics are not pretty.

It takes about an hour and a half to pull the intake; it's cheap insurance to remove it and find the pin. If it gets into a cylinder, it WILL destroy the head.

Do a compression check of all 6 cylinders. If they are all normal, just have the car towed to a mechanic and explain to him that you need the intake manifold remove and to search for a steel pin.

If one cylinder is low, Bingo you just found where the pin is.

E53 is a great car to work on. You would learn a ton about the engine if you do the intake off/on.

Before doing that I would do this: put the front on jack stands. Remove the belly pan and clean it off through a screen. I'd be willing to bet $5 the pin is on the belly pan. I've lost things 20x as large.


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Any update?


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UPDATE:

I bought a replacement DISA (OEM).

I bought an inspection camera. Spent hours looking for the DISA pin, but couldn't find it.

So, I removed the intake which took a very long time. Daunting for sure. I'll be replacing the CCV (as it was entirely cracked).

But the PIN is NOT in the intake!

I took a photo of the valve which looks like it has metal shards. Do you think that could be the pin?

Link to photo of Valve


Here is a a video of most of the pins. Does anything look wrong there?
https://drive.google.com/file/d/0Bze...hTb3lwQnM/view

Could any of these ODB faults be related to the PIN?

- Powertrain Faults P1349, P1351, and P1354 "Misfire Cylinder X with fuel cut-off '" (that's' cylinders 4, 5 and 6)

- Error P0102 (MAF low input)

- P0155 (O2 Sensor Heat Circuit).

- Pending fault- P0300 ("Random/multiple cylinder misfire detected").

^It's hard to tell what that debris used to be. It's certainly appears to be the right material to be the DISA pin... but it could also be aluminum from something else.

One thing I do know... if it is metal, that debris will keep your valves from sealing against the head and will cause compression problems (lots of misfires) and potentially more serious problems... head damage, piston damage, valve damage, etc. :(

So what should I do next then? You've got be super worried now as I"m already getting misfire codes on cylinders 4, 5 & 6...

DISA pin is steel I believe. If that fell in I would expect it would get caught in the valve seat it would cause an explosive back fire through the intake if the valve didn't seat. If it cleared the valve it would be in the cylinder and would rattle around something fierce. You could likely get a view into the cylinder with your camera to get an understanding of did the pin get in there.

Use a magnet on that debris and figure out if aluminum or steel. Either way it can cause bad seal on the valves and kill compression.

Were it me I would take out the plugs, inspect each cylinder, clean the mystery metal off all the valves and inspect them all for damage.

Once clean check all the cylinders for compression. If they check out put it back together and start knocking out errors


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Ah, never stuck a magnet on it. Always thought it was aluminum.

I'd follow andrew's plan of attack. Clear the cylinders (and valve chambers) of debris, check for damage, compression check. If good, proceed from there with DISA rebuild.