Dropped set screw into IMS bearing flange hole
 

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?

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.

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............

Motor
 

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

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.

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.

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.

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

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

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.

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.

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.

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.

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

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.
http://i1045.photobucket.com/albums/...ps4cwedyzo.jpg
As Jake said, do not start this engine.

old refrigerator magnet.?
 

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...

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:
http://986forum.com/forums/uploads01...1421816170.jpg

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.

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

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.

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!

If you can bend a coat hanger to reach the set screw then there maybe a shot .Make a magnet out of the coat hanger and single strand of copper wire -once wrapped use heat shrink tube to cover the coil .A 9 volt battery should be fine .

The problem you'll have with magnets is all the other heavy ferrous parts that are near this area. This includes the IMS drive, and its chain. The magnet will want to be attracted to these, before the missing fastener.

OK, then how does he find the set screw?

3M, double-sided tape lol

seriously. The stickiest you can find

Just goog'ed some pretty neat Vacuum Pickup Tools. You'd possibly need something bigger than a hobby size tool tho. Just trowing some ideas for you, not that I've done that before

Feel ya from this side, wish you and your car the best of luck man :/

The set screw is in a place that a tool can not get to. I took a good look as I finished disassembling an engine today. Even with the head off and chain ramps removed, it didn't seem doable.

So, how about moving it to out of the IMS pit with a jet of air or fluid. You can push flexible tubing down there. If you can get the set screw to another spot, you have a much better chance of reaching it.

Progress report
- I was able to slip a zip tie into the exact area where the set screw is. A coat hanger is either too large in diameter or too rigid (I think the former).

- I confirmed the screw is in that area by moving it around with a magnet outside the case and taking a video from inside. I tried this before but visibility was poor - vacuuming up most of the oil helped. Note in plain sight in the video is the IMS-crankshaft chain/sprocket. The screw is on the other side of it - I'm wiggling it around through the case with a magnet, and you can see the oil slosh around as a result.

http://cdn.makeagif.com/media/1-22-2015/eXzRws.gif

- I tried moving the screw to the area that is visible by the camera, but it doesn't seem to go over there. Hypothesis is there isn't enough clearance beneath the IMS-crankshaft chain.

- Thus I have begun a project of trying to create enough clearance to move the screw to the area accessible by tools (seen in camera). First attempt was to tighten down the IMS-crankshaft tensioner and hope this would lift the IMS enough to scoot screw under. Tried once and failed.

- Another idea is to move the IMS up by sticking a pole into the hollow shaft and lifting up the pole. I've heard it's not to difficult to maneuver the IMS around like this. At present my LN engineering bearing is installed, including the center stud, making it impossible to fit a pole inside. I don't want to mess up the bearing by knocking out the support stud. Bad idea to knock the stud back into the IMS shaft and later reattach it to an already installed bearing? Other ideas of prying the IMS up?

Thanks to all.

Been following your progress with interest. I have always prided myself with having good problem solving skills and this one keeps me engaged. Not having in person first hand knowledge of the problem site makes it even more of a challenge.
First, I would like to know if you can rotate the chain and sprocket?
If that is possible, this is what I had in mind.
Get some of those small rare earth magnets and stick them on the chain in between the sprocket teeth. Rotate the chain and sprocket to where the set screw is and see if they can attract it and stick to the magnets. If they do, you can rotate the chain back and grab the set screw. Not much chance of losing the magnets, as they stick like crazy to anything ferrous. Just make sure to count how many magnets you use and account for them afterwards. The ones in the picture are from Harbor 'Fright'.

edit:
* Opps, I see that you have already thought of this upon reading earlier posts.*

http://986forum.com/forums/uploads01...1421915152.jpg

Thinking more about it, it's probably not a great idea to pry the intermediate shaft up like that if it can be avoided. I don't want to damage the race that holds it in place on the other side.

Thinking even more about it, from the photo from flaps10, it seems like there should be enough clearance for the set screw to fit beneath the chain (looks to be 6mm or more - I can't tell for sure). The screw might be running up against the lip of that recess. I'll try to vacuum up even more oil to see if I can make the floor visible.

There are also holes in the sprocket big enough to fit the screw through.

And really, how about a hole in the case? Expand the bottom left IMS flange bolt to be M8 or M10 instead of M6?

Many clever ideas. Thanks again. Will surely get to try many of them in days, weeks, months ahead.

I would not put any permanent magnet inside the engine. Electromagnet would be ok. A rare earth magnet will stick to anything ferrous and not come off. You will lose it in there and then have an even bigger problem. I'd get stronger magnets to use from the outside of the case to drag the screw up out of the hole. If you can pull the screw up high enough to touch the screw with the end of a coat hanger while both are in the magnetic field it will tend to stick to the coat hanger. As mentioned earlier the screw will be attracted to the IMS and chain as well as the magnets while both are in a magnetic field so you can expect to have to wiggle the magnet around a fair bit to tease out the screw. Away from ferrous material you should be able to move the screw around at will.

I hate to say it, you'll probably never get it out.

You know what I would do?

Curse. A lot

Next, I'd cry for a little while

Then I'd pull the engine down and take it apart.


I hope you can find a way to figure it out, but things arent looking too good for you.

[QUOTE=Bigsmoothlee;432776]I hate to say it, you'll probably never get it out.

QUOTE]

Don't give up yet, you might be on the one yard line! The fastener is in the "U" shaped channel in the lower right hand corner of this picture. Use a strong magnet from outside the block to drag the fastener up the ramp out of the channel. This would be dragging "into" and "up" for this picture. Once dragged up the ramp it's no longer in the channel and you might be able to see it with your endoscope. Pull it towards the center of the engine. If it drops from there you can grab it again through the aluminum with magnets from inside the oil reservoir area, in fact having magnets taped to the area you want the fastener to go might be a good move. Then drag it up to the large hole under the cylinders and into your hand. When you get this bolt out you need a vanity plate that says "986FISH".

One other thing, the gray oval on the casting near the hole for the IMS seal is where the IMS drive chain kissed the block after a complete IMSB failure with a broken bolt. After quite a bit of bolt turning in my garage the engine is in my daily driver and runs like a top. Never give up!

http://986forum.com/forums/uploads01...1421959747.jpg

If you can wiggle it with a small magnet from outside the case then you can move it with authority with a big enough one. Oh and soak up that oil- it causes drag...

Just want you to know that we've all been there and done something like this at one time or another. You have an army of guys trying to help figure this out and hope that you are successful.

I'm glad that there was no internet the time that I cracked the head and broke a chunk out of the block when I forgot to remove a somewhat hidden head bolt and went ahead and gave it a little "help". Yeah, it happens to all of us.

Access though the IMS tensioner hole may yield some results, too.

You can tear the engine down "on the half shell" and leave all of bank 1 together, only removing the exhaust cam sprocket bolts, locking the bank 1 cams in place. This allows complete disassembly of bank 2, and access to the IMS region to fetch this fastener, without total engine disassembly.

We do this all the time in development, changing components for back to back tests.

If the possibility of using a magnet from the outside of the case sounds like something you might try, get one of these from Harbor Fright'. It is the strongest magnet I have come across that is easily obtained.
Retrieving Magnet, 250 Lb. Pull

Got one to retrieve tools that get dropped off the dock when working on the boat. If you have ever been around boats, then you know that its only a matter of time until something visits Davy Jones.
Here's a pic of it holding a 5/16" set screw through a 1" thick bar of aluminum.
If you lived closer, I'd let you borrow mine. They are currently on sale for $19.99

http://986forum.com/forums/uploads01...1421999184.jpg

If you get that magnet near the engine you'll magnetize the IMSB. Doing this guarantees that any ferrous debris inside the engine will be sucked into the races of the bearing. This causes certain death.

I have seen this before, and we have to stay join the asses of distributors NOT to ship IMSBs with magnetic drain plugs.

Also, if you magnetize the lifters, they'll suck up debris and the engine will sound like a small diesel.

Magnets that are this powerful have mo place around an engine.

There;s a time when avoiding the issue creates other issues. I'd suck it up and take it apart.

Maybe you can buy a flexible camera probe and see where it is.

+1..........

It is going to require a very small camera head to get in there, which will be expensive.