growthroughlife

I’m currently at the end of my disassembly for the timing belt and water pump job on my 1992 LS400. As I was cleaning off the RTV for the water pump with a razor however, I dropped the small, thin blade into the water inlet. I tried to recover it for over an hour with all kinds of magnets and could not get it out, not even sure if I ever grabbed onto it with any magnet.

I don’t think it’ll be able to fit through any of the passages, though it may block or restrict coolant flow. I’m not sure what to do here and I’m wondering if anyone has dealt with anything similar, or if I’m better off just letting it live in my engine for the rest of its life.

CELSI0R

That's a pain!!

I would try to get it out, but in order to do so, I would first try to look up pictures of the block to see if you can figure out where that passage goes

- https://www.clublexus.com/forums/per...l#&gid=1&pid=1
- https://www.driftworks.com/forum/thr...-parts.287118/


Trying to flush the system could help to push it back out where it fell in, or it could send it further into the engine where it could cause a blockage or restrict flow. It's really hard to say...

What you really need is a cooling flow diagram for the 1UZ-FE

EDIT: You're partially in luck. I found this cooling flow diagram, but it doesn't show where that passage goes exactly.

It does however tell you where the coolant flows normally.

What happens on the right side of your engine is probably what happens on the left (shown in the photo). When coolant goes through that hole on both sides, it's then forced up through the cylinder heads, and then goes to the heater or the front water joint.

If you reverse the flow, maybe you can get the blade out, but I'm not sure what the side effects will be (other than a mess)

bradland

So if I’m reading this right it fell into the inlet hole in the second pic behind the water pump?
I would definitely want to get it out. You might be able to open the drain petcock on the pass side of the block and apply some compressed air.
This might push it back toward the hole it fell through…
Another option is find a magnet shaped like a washer and affix it to some fairly flexible electrical wire and fish it through the inlet passage.
Maybe a combination of both..?

growthroughlife

Really appreciate this reply. I did find a few pictures to help visualize what I’m dealing with here, but the ones you provided are more useful. I do think back flushing it could be a viable solution, though as you said it does run the risk of it getting trapped further into the engine, or getting caught on something. Also it does appear that the water inlet flows directly to the reservoir tank, which is less worrisome for me, though I could be reading the diagram wrong.

Ideally I’d like to attempt to get it out with a magnet first. I just ordered some steel wire and some strong neodymium magnets. I can hopefully magnetize the wire and finagle it around the inlet until it catches. If this doesn’t work then flushing will be my next option.

growthroughlife

Yes that is correct it is the inlet in the second picture where the blade fell, and subsequent made a plop sound as it sunk into the coolant and my heart dropped. Just taught me a very valuable lesson to cover any holes leading into the engine with some shop towels.

I found some flat, round neodymium magnets with a hole in the center. I was going to attempt to string something through the middle and fish it through there. I also got some steel wire to potentially try and magnetize and fish it out with that. Back flushing through the drain petcock is an option, but something I won’t try until I’ve determined the magnets aren’t working.

aptoslexus

As far as the magnets go, an endoscopic camera could be helpful. Some of them have magnetic attachments that hook onto the end of the line that you can snag metal while being able to see what you're doing.

TominPT

This is what Car Care Nut recommends - might be worth a try.
Very Good Triple Camera Borescope https://amzn.to/3MrgFs0

growthroughlife

I’ve ordered an endoscope camera off Amazon, just went with the Depstech brand because it was eligible for overnight shipping. It doesn’t have a magnet at the end of it unfortunately. A little worried about what I’ll do if I actually do see it down there, at least I’ll know where it is. Going to be at work all day so won’t have a chance to give it a try till later tonight.

TominPT

I think that if you can see it you should be able to extract it with the strongest magnet you can find at the end of a probe (or the camera). Could it have fallen into the water pump? That would truly be bad. But you could in theory remove the pump and then search around from there.