Dropped set screw into IMS bearing flange hole

[gonzojive]

I dropped a set screw into the engine case beneath the IMS bearing. I have been trying to get it out, no luck. I have tried

1) removing the oil pan and accessing the recess through there, but I couldn't find a path
2) going along the chain that links the IMS to the camshafts for cyls 1-3 (flywheel side). Could not fit a tool into there, or my 1cm endoscope.
3) getting it out while I had the IMS bearing flange off to replace my IMS bearing. Not enough clearance. But I probably should have tried harder, and at that point my engine was not at TDC. Perhaps at TDC I will be able to move the IMS enough to fit a magnet on a string in there? I'm guessing not.

Let me hope I don't need to drop the engine for this 10mm set screw, for which I have already gone to the trouble of retiming 1 bank of camshafts.

Aside from how to get it out, what will this screw do to the engine if I leave it? I haven't found a photo or diagram that shows how much space is beneath the IMS bearing area or how this area is connected to the rest of the engine. Will it just sit there in a recess indefinitely? Will it get sucked into the sieve in the oil pan area?

[gonzojive]

Thanks again Pelican Parts for a helpful photo.
http://www.pelicanparts.com/techarticles/Boxster_Tech/14-ENGINE-Intermediate_Shaft_Bearing/images_large/Pic044.jpg

Basically there's no space beneath the flywheel-side IMS sprocket.

[JFP in PA]

Originally Posted by gonzojive

I dropped a set screw into the engine case beneath the IMS bearing. I have been trying to get it out, no luck. I have tried

1) removing the oil pan and accessing the recess through there, but I couldn't find a path
2) going along the chain that links the IMS to the camshafts for cyls 1-3 (flywheel side). Could not fit a tool into there, or my 1cm endoscope.
3) getting it out while I had the IMS bearing flange off to replace my IMS bearing. Not enough clearance. But I probably should have tried harder, and at that point my engine was not at TDC. Perhaps at TDC I will be able to move the IMS enough to fit a magnet on a string in there? I'm guessing not.

Let me hope I don't need to drop the engine for this 10mm set screw, for which I have already gone to the trouble of retiming 1 bank of camshafts.

Aside from how to get it out, what will this screw do to the engine if I leave it? I haven't found a photo or diagram that shows how much space is beneath the IMS bearing area or how this area is connected to the rest of the engine. Will it just sit there in a recess indefinitely? Will it get sucked into the sieve in the oil pan area?

Basically, it can chew it to pieces if it gets picked up in the cam drives. You need to get it out. And if you are doing an IMS swap, why are you not at TDC? Really bad idea............

[Reebuck1]

If you start the motor without removing the screw.....THE MOTOR IS TOAST!!!!
I found out the hard way.

[78F350]

My bad idea for the day has to do with using a very strong magnet on the outside of the aluminum case...

I really empathize with you, but after following along some of your history since the 'off center' post in November, I think that it may be time to stop digging in deeper and have someone else take over the recovery, or at least be present to help.

There are still many things that can go wrong before it is all done.

edit: My aircraft mechanic just said you should try using a strong magnet on the side of a long rod or flat-tip screwdriver, passing the magnetism to the tip.

[Jake Raby]

I see people doing this all the time. The original procedure that I developed for IMS Retrofit doesn't use set screws and doesn't allow this to occur.

There's a small area at the bottom of the crankcase that will usually catch this bolt. Accessing this is questionable.

Do not start the engine!! If you do, the bolt will be drawn into the IMS drive chain and will create a massive failure.

[Topless]

I sure wish this antiquated DIY IMS procedure that fails to suggest going to TDC and locking the cams, and suggests using set screws would just evaporate into space. There are better choices that don't FUBAR a bunch of motors.

[woodsman]

coat hanger with a magnet crazy glued on it???

[JFP in PA]

Originally Posted by Topless

I sure wish this antiquated DIY IMS procedure that fails to suggest going to TDC and locking the cams, and suggests using set screws would just evaporate into space. There are better choices that don't FUBAR a bunch of motors.

People go for it because it is cheap, and looks simple; and unfortunately they often get exactly what they paid for................

[Jamesp]

Originally Posted by woodsman

coat hanger with a magnet crazy glued on it???

Not crazy glue. stretched electrical tape with a loop on the end of the coat hanger so the magnet wont slip off. The problem is the screw is likely to stick to the ferrous metal around it and not to the magnet when the magnet is near. I don't know why, but I have data.

Also, a dental mirror and a flashlight can be darned effective at locating lost things in small places.

[BYprodriver]

Maybe you can "Flood" it out by raising the front of the car/ engine & pouring new oil in until it runs out the IMS hole. Set screw probably won't fall out, but should get washed to the IMS hole.

[coreseller]

Originally Posted by Topless

I sure wish this antiquated DIY IMS procedure that fails to suggest going to TDC and locking the cams, and suggests using set screws would just evaporate into space. There are better choices that don't FUBAR a bunch of motors.

I did my LN IMS Bearing upgrade several years ago, which set of instructions does not mention TDC or locking the cams?

I gotta admit the more I read on individuals doing this themselves the more fortunate I feel mine went smoothly.

[Jamesp]

So if I were desperate, and I would be, I'd use a dental mirror and a flashlight to spot that sucker. If I could see it, I'd go for a long piece of tagon tube attached to the suction of my shop vac. OD of tagon would be driven by the available clearance at the IMSB. It would certainly suck, and might work. In fact I'd give this a shot even if I could not see the lost fastener and ended up just fishing around. Would it work? Maybe.

[JFP in PA]

Originally Posted by coreseller

I did my LN IMS Bearing upgrade several years ago, which set of instructions does not mention TDC or locking the cams?

I gotta admit the more I read on individuals doing this themselves the more fortunate I feel mine went smoothly.

The instruction set is Pelican's............

[flaps10]

I took this so you can see where your screw is. No one is getting a dentist mirror or any device of size in they to retrieve the screw.

As Jake said, do not start this engine.

[Gilles]

Flaps,
Through that small gap could you be able to push down a (long) magnet from an old refrigerator door..? Hoping to pick up the screw when you pull it out?
At least is magnetic and flexible...

[gonzojive]

Originally Posted by flaps10

I took this so you can see where your screw is. No one is getting a dentist mirror or any device of size in they to retrieve the screw.

As Jake said, do not start this engine.

Thank you all for the sobering advice. flaps10, very helpful high resolution photo.

I managed to get a vacuum hose and endoscope into the area beneath the IMS-camshaft chain. But still not able to get a tool into the spot where the screw is - beneath the IMS-crankshaft chain. (Here's video taken with the endoscope going through the horizontal hole for the driver's side chain tensioner. I can't get the scope to the other side of the final sprocket, where the screw is: https://www.youtube.com/watch?v=Wb5LyAzlFUs&edit=vd ) I marked up flap10's photo to illustrate:


One idea is to stick a small magnet to the IMS-crankshaft chain (through the tensioner hole), then turn the crank until the magnet makes it to where the screw is. The magnet could pick up the screw, and then I'd turn the crank the other way to get it to near the tensioner area, where I could grab it.

Another idea is to drill a hole in the bottom of the engine case and retrieve the screw through there. Not sure if that is at all reasonable yet.

[78F350]

Originally Posted by Gilles

Flaps,
Through that small gap could you be able to push down a (long) magnet from an old refrigerator door..? Hoping to pick up the screw when you pull it out?
At least is magnetic and flexible...

Caution: Risk of bits of magnet breaking off and attaching to chains, gears, etc.

[Jake Raby]

Originally Posted by Topless

I sure wish this antiquated DIY IMS procedure that fails to suggest going to TDC and locking the cams, and suggests using set screws would just evaporate into space. There are better choices that don't FUBAR a bunch of motors.

This is what happens when the person who developed the procedure hasn't done it themselves enough times to have learned from mistakes.

People lern the hard way what to buy, and who to listen to. I lerned long ago that I can lead a human to knowledge, but I can't make them think.

[Jamesp]

I've been thinking about this problem and it seems clear that space is too limited to reach in and grab the lost fastener. You may be able to "walk" the fastener out of the block using neomydium magnets from the outside of the case. The magnetic field should easily penetrate the aluminum. I looked at the case geometry at it appears there may be clearance to move the fastener out of the well it is in using magnets from the outside of the case then to the point you say you can see with your endoscope then over to the opening in the block over the oil pan then into your hand. This will require rare earth magnets but seems like the best shot to me. The magnets never enter the case where they would stick to every ferrous thing in there you don't want them to. If you need pics I can post them after I'm home from work. And now, back to lunch!