Valve cover gasket job gone bad - dropped nut into timing chain cavity (1 Viewer)

[DangBird]

While doing a valve cover gasket job on the 1997 LX450 today, the last valve cover bolt snapped when removing it. Thankfully it's in the front corner on the driver's side so it's easy to get to. There was a bit of thread still sticking out, so I thought I could thread two nuts onto the top, tighten in opposite directions, and use that to remove the stuck piece of bolt.

Well.. that was a huge mistake. In my haste to extract the broken bolt I managed to drop one of the nuts into the open valve cover cavity. It dropped near the timing chain. I can't see the dropped nut and have had no luck fishing it out with magnets the past couple hours...

What's the best course of action here? Was planning on doing the oil pump cover and crank seal soon, but haven't done those on this engine before. When the front crank seal is out is there enough room to get a snake magnet in there?

Here's a picture of the broken stud and area the bolt dropped into... it made a horrifying plinko sound all the way down. Thanks in advance for any ideas!

 

[Feistl]

Long shot I know, but I had a very similar situation a while ago… I was able to remove the oil level sensor on the side of the sump, then using a magnet on a bit of welding wire was able to get the nut out. Only took like 10 minutes and was the quickest way…

Alternatively, drop the sump and while you’re in there change the big end bearings…

Good luck

 

[DangBird]

Long shot I know, but I had a very similar situation a while ago… I was able to remove the oil level sensor on the side of the sump, then using a magnet on a bit of welding wire was able to get the nut out. Only took like 10 minutes and was the quickest way…

Alternatively, drop the sump and while you’re in there change the big end bearings…

Good luck

That's an access point I haven't considered yet. New to working on the 1FZ-FE engine. Thank you!
Did you drop something in that same spot and/or have no luck fishing it out of the top also?

 

[Feistl]

Was actually on a 1HDFT motor, but same problem and no luck from above. Its very probable the nut has ended up in the sump, you may not have heard it hit the bottom as it would have landed in the oil... but in a worst case scenario its just a matter of dropping the sump out which is a pain, but not THAT big a deal

 

[JoeCova]

Problem is you have no idea where it is, could be stuck on a drive gear but hope it fell through the the oil pan. The number 1 oil pan has a baffle in it that it could be sitting on. You could go through the oil level sensor or simply remove the number 2 pan to verify its not there and then gain access to the underside of the number 1 pan and give you a but more room to work around the baffle. Unfortunately the baffle can only be removed with the number 1 pan removed as well. Removing the number 1 pan requires you to raise the engine a few inches which is a PITA

 

[DangBird]

Problem is you have no idea where it is, could be stuck on a drive gear but hope it fell through the the oil pan. The number 1 oil pan has a baffle in it that it could be sitting on. You could go through the oil level sensor or simply remove the number 2 pan to verify its not there and then gain access to the underside of the number 1 pan and give you a but more room to work around the baffle.

Yeah, exactly. Not something I'm willing to leave to chance either... too much potential for it to be in a bad spot. I didn't drain the oil yet since I thought it might shift it around. I'll do that in the morning since I got skunked fishing for it topside, though.

Will try to find diagrams depicting that baffle too. Thanks for the heads up about that!

 

[JoeCova]

Yeah, exactly. Not something I'm willing to leave to chance either... too much potential for it to be in a bad spot. I didn't drain the oil yet since I thought it might shift it around. I'll do that in the morning since I got skunked fishing for it topside, though.

Will try to find diagrams depicting that baffle too. Thanks for the heads up about that!

I found some old pictures of when I did my engine rebuild and this shows the baffle in Oil pan #1. Also have a picture of the oil level sensor (my was broken) with the baffle in the background.

My guess and hope is that it fell past the drive gears and is sitting in the front of the pan.

 

[DangBird]

Thanks @JoeCova. Really hope I don't need to take the pans off to get to this dang thing. I do have a large fishing magnet that might be able to drag it along the bottom of the pan too. Will report back tomorrow on any progress.

 

[Kernal]

Amazon.com : cell phone borescope camera

 

[DangBird]

Thanks @Kernal. I got a similar camera at Lowe's yesterday. Still haven't found that stupid nut.

Yesterday looked everywhere with the camera from the top side, and also from the bottom after pulling off the first oil pan (the easy one). Tried magnet fishing again from both top and bottom but didn't catch anything. I carefully rotated the crank pulley to see if anything would bind, but it rotates freely, so that's a good sign? Was able to do an entire revolution, so my guess is that the nut is at the bottom of the timing cover.

Thank you to all of you for the help.... will post back when fishing is successful.

 

[DangBird]

Alright... beginning to question whether it's better to spend more hours with the camera and/or magnet, or if it's time better spent tearing things apart. I had planned on doing oil pump gasket and distributor O-ring at some point, but upon closer inspection of that area I think the biggest oil leak is (unfortunately) coming from the high pressure O-ring underneath the timing cover anyway.

Guess I might be joining the "head gasket as preventative maintenance" club?

 

[manofthewoods]

Alright... beginning to question whether it's better to spend more hours with the camera and/or magnet, or if it's time better spent tearing things apart. I had planned on doing oil pump gasket and distributor O-ring at some point, but upon closer inspection of that area I think the biggest oil leak is (unfortunately) coming from the high pressure O-ring underneath the timing cover anyway.

Guess I might be joining the "head gasket as preventative maintenance" club?

Just my opinion, but pulling the engine isn't that tough, and makes every job so, so, easy.

 

[OGBeno]

Damn son….. no bueno.

Pull it and be done with it.

You are wasting more time with MUD clowns when you could have the nut out in your hand.

 

[DangBird]

Damn son….. no bueno.

Pull it and be done with it.

You are wasting more time with MUD clowns when you could have the nut out in your hand.

Yep, it's time. What an exciting learning experience this will be! What I'm trying to say is...someone send beer.

 

[TomH]

Did you check the lower pan closely for the nut? I recently lost the woodruff key out of the crank and found it in the lower pan.

 

[DangBird]

Did you check the lower pan closely for the nut? I recently lost the woodruff key out of the crank and found it in the lower pan.

Yeah, I took the lower pan off and it unfortunately wasn’t there. Really hoped it was going to be taken there on a river of oil after draining it.

Have spent hours now trying to find it with a bore scope and magnets in the other pan from below too.

 

[jpoole]

Have been hoping for a good news update on this one.

Although breaking things down further is the guaranteed path to success I wanted to add that I could see scenarios where it makes sense to try to fish the bolt fragment out before diving in. For instance if it's going to be a while before you are ready to dive into the more involved disassembly/removal work yet you often have a little spare time at night to chip away at this, etc.

If you do end up spending a little more time trying to recover this bolt-end before pulling things further apart I wanted to throw out a few additional ideas I've not seen mentioned here. One would be to use a fluid to try to dislodge it and help it fall to the lower sump area. This could be compressed air with a long wand/extension or a pump and heavier fluid like diesel fuel, oil or similar. You could, for instance setup a recirculating system if you used a liquid and could try to flush the piece out by spraying a jet of fluid as you move the wand end all around inside the timing chain area, etc.. You may end up lodging the bolt-end further in it's hidey hole but if you are already considering pulling the engine and tearing it down that's not a big risk in my opinion. I've used small diameter copper tubing to make wands like this for compressed air/etc. in the past and they can work pretty well since they are easily adjusted and the end can be shaped/crimped into a nozzle. If used gently no damage to engine internals should be possible and the soft copper helps on that front though you still don't want to go banging it against the timing chain slippers (or anything else in there for that matter).

I'm not sure the magnet setup you've been using but there could be room for improvement there also though it seems likely that you've done a pretty thorough job on that front.

Good luck with it.

 

[DangBird]

Believe I've found it! It's visible in the hole that the crankshaft position sensor goes in. This is looking up from the bottom, you can see part of the nut up against that cog in front of the timing gear. Happy I found it. As suggested, it's sitting on the upper oil pan!

Pulling that pan tonight and should have it reassembled this weekend sometime.

Thanks to everyone for the suggestions! Also.... please send more

 

[DangBird]

Okay, have another positive update for everyone. Firstly, thank you again to everyone who gave suggestions and helped! This was some (unnecessary) PM that turned into quite the saga... Also thanks to @90WT for sending beer and moral support.

To summarize the story:

• Snapped front driver side valve cover bolt when taking off the valve cover. Decided to do this because I "already had the parts"...
• Attempted to thread two nuts together on what was left of the bolt, and butterfingered one into the open timing chain cover. Pro tip: put a dang rag in there.... don't be like me.
• Spent lots of time with magnets and a snake camera fishing for the thing.
• Drained everything, pulled radiator, and both oil pans (yes, oil pan #1 the upper pan is a PITA)
• The nut was sitting at the bottom of the timing cover, in the semicircle up against the crank cog. Was able to use a guitar string and a small hose pick to flick it up and out on the side. Finally found it!
• Now... back to the original problem, the snapped bolt in the head. Tried everything to get the dang thing out. It was IN there...
• Broke a bolt extractor (the straight drill-through-then-hammer-in kind) off in the bolt. Crap.
• Spent an entire day (seriously, 7 hours) with a dremel and full carbide bits drilling. Got most of it, but the top threads were starting to get bored out anytime the bit would skip or loose its center.
• Decided it's best to use the threads that work and a few washers (pictured below) since these things are not torqued much.
• Did other while-im-in-there stuff. Crank seal, oil pump seal, timing cover seal (in big oil pan), dipstick oring... Most parts I already had sitting anyway
• Put it all back together, filled with fluids, driving again

So I hope this thread is entertaining at the very least. I get a good laugh thinking back on it now..... next time I'll put a rag in there as soon as it gets opened up!

Oh, and the real kicker: the nut I dropped in there was stainless -- as in not magnetic.

I didn't take as many pictures as I should've, but here are a few that I did take:

 

[OGBeno]

Good work.