dropped nut into timing chain cavity

[Dash01]

If a nut or bolt were to fall into the timing chain cavity (while upper timing case removed), can the nut fall down into the oil pan, or is there a floor under the main sprocket that would stop the fall?

In other words, which sections of the engine are at risk?

I've poked around down there with a magnet, but no luck so far. Can't see much, either.

[yaofeng]

it should fall into the sump. See picture. The engine is upside down.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1711-1.jpg

[Dash01]

Thanks for the picture and info, which are very helpful.

So, I should be able to insert a telescoping magnet into the oil drain plug hole and retrieve the lost nut? The oil pan is aluminum, so perhaps dragging a magnet across the bottom will draw the nut toward the drain plug hole?

[Dash01]

BTW, has invented an affordable laparoscope (or similar) to inspect remote and otherwise inaccessible places?

[Evan]

drop the pan and find the nut before you do anything else

[Dash01]

drop the pan and find the nut before you do anything else


Do you think insertion of a telescoping magnet into the drain plug hole will work?

[bill g]

You really need to know where that nut is. You do not want it to get caught between a gear or cog and the chain - that will cause some grief.
If it is just sitting on the bottom of the oil pan then you could just leave it there.
Waving a magnet on a telescopic arm around in there should not do any harm - you might get lucky.

Bill G

[Evan]

use your imagination on this one... but find it.

what kind of motor is in your car? fix up your public profile so we know what you're driving.

[Dash01]

Would removing the oil level indicator from the bottom of the pan provide access to the pan interior, to retreive the lost nut? With this out, and by using a dental mirror as a periscope, could I see inside the oil pan?

The timing chain and drive gears at the front end of the crank are clear, so the nut is not visible there.

[DanH]

There are some baffles in the oil pan that may make it difficult to get the nut out without removing it.

Perhaps you have a leaky oil pan gasket that needs to be replaced anyway?
IIRC, you are replacing the headgasket, if you have not put it back together yet, then the oil pan removal is a much easier job with the upper parts of the engine removed, since its easier to jack up and drop the pan. You'll get the nut out at the same time.

[yaofeng]

There are some baffles in the oil pan that may make it difficult to get the nut out without removing it.

Perhaps you have a leaky oil pan gasket that needs to be replaced anyway?
IIRC, you are replacing the headgasket, if you have not put it back together yet, then the oil pan removal is a much easier job with the upper parts of the engine removed, since its easier to jack up and drop the pan. You'll get the nut out at the same time.

The baffle is bolted to the block so it sits high on the sump at the level of where the sump meets the block. It is also set back behind the oil pump which is located near the front as it is chain driven. It is very unlikely the nut will end up on the baffle.

See the two rows of bolt holes inside of the bolt line for the sump? The eight bolt holes set back from the block are for the baffle.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1712.jpg

[Jeff N.]

Maybe this will help?

http://home.comcast.net/~jsnord/pics/eng_front_new.jpg

Couple thoughts -

Dan's correct about the baffles. The nut may be sitting on top of them. Or, it may not. It could also be stuck in the tensioner mechanism for either the oil chain or the timing chain. Worth getting a long magnet on an extension and fishing around in those areas to see if you can nab it.

Your idea to remove the oil level sender to check the bottom of the pan is a good one. I'd make something that would allow you to get a magnet on a 60 degree angle or so and fish around with the sender removed. Removing it is simple and you'll get a pretty big hole. You may just find it. Of course, if it's on top of the baffle, you may be hosed. I do have a pan at home sitting in the garage to that I can try to look at to see how likely it is for a nut to end up on top of the baffle.

Dan's also right that now's a great time to replace the pan gasket. It's much simpler to get the motor high enough with the head off.

Sorry to hear about this - I always cram a rag in the timing chain gap to minimize the chances of something like this happening. Be good to hear what works to get it out. I'm sure I'll do the same one of these days...

Cheers!

Jeff


There are some baffles in the oil pan that may make it difficult to get the nut out without removing it.

Perhaps you have a leaky oil pan gasket that needs to be replaced anyway?
IIRC, you are replacing the headgasket, if you have not put it back together yet, then the oil pan removal is a much easier job with the upper parts of the engine removed, since its easier to jack up and drop the pan. You'll get the nut out at the same time.

[Dash01]

Thanks, Jeff, for the pic and info. If you could pls. describe or photo the oil pan, that would sure help to visualize the likely destination of the errant nut, which fell in from the driver's side of of the timing chain cover's top.

From your pic, it looks like pretty much a straight shot down the chain gallery to the front part of the oil pan. My OP is angled aft at the bottom, to a flat and level floor surrounding the oil level indicator. So, next to remove that and search with a magnet and dental mirror. Magnet from the top of the front cover produced nothing.

Sadly, this happened AFTER re-installation of the new head, exh. manifolds and pipes, fuel inj., wiring harness, vacuum tubing, etc..

Again, any further description of depiction of the interior of the oil pan would be MUCH appreciated!






Maybe this will help?

http://home.comcast.net/~jsnord/pics/eng_front_new.jpg

Couple thoughts -

Dan's correct about the baffles. The nut may be sitting on top of them. Or, it may not. It could also be stuck in the tensioner mechanism for either the oil chain or the timing chain. Worth getting a long magnet on an extension and fishing around in those areas to see if you can nab it.

Your idea to remove the oil level sender to check the bottom of the pan is a good one. I'd make something that would allow you to get a magnet on a 60 degree angle or so and fish around with the sender removed. Removing it is simple and you'll get a pretty big hole. You may just find it. Of course, if it's on top of the baffle, you may be hosed. I do have a pan at home sitting in the garage to that I can try to look at to see how likely it is for a nut to end up on top of the baffle.

Dan's also right that now's a great time to replace the pan gasket. It's much simpler to get the motor high enough with the head off.

Sorry to hear about this - I always cram a rag in the timing chain gap to minimize the chances of something like this happening. Be good to hear what works to get it out. I'm sure I'll do the same one of these days...

Cheers!

Jeff

[Dash01]

Thanks very much Yaofeng, for the excellent pictures and description. It looks as if the most likely path for the nut was down the driver's side of the front cover, bounce off the sprockets, then straight down into the front section of the oil pan. In the next few minutes I'll remove the oil level indicator and look/feel around inside for the nut. A dental mirror, flashlight, and magnet will help with this.