I managed to drop a valve adjusting shim into the engine, area A in the attached. Yeah, I know I should have blocked the hole, but I didn't notice it until too late. Dumb, dumb, dumb! It's the end one of course, on the driver's side that is hardest to get to (the one that usually causes the ticking).

According to the 1994 manual (mine is a 1991 LS400) if this happens the shim goes to the oil pan, which I will have to remove to retrieve it. I tried putting a magnetic pickup down the hole, but it seems pretty tight for the shim to get through (or back up again) and I have not been successful.

Has anyone else done this? Is the shim likely in the pan, or stuck somewhere halfway between? How big a deal is it to take off the oil pan? Should I keep trying with the magnetic pickup?

 

god love ya

 

that'll make a preacher curse!

 

If it's in the oil return passages, I wouldn't worry too much. But if the shim dropped into the cam gear area, you might as well pull the exhaust cam and take it out.

 

It is in area A, which I believe is the oil return passage. I tried again with the magnetic pickup, but no luck. Oh well, the oil pan gasket looks like it was leaking a bit anyway judging by the amount of crud there, so looks like the oil pan is coming off.

 

Update: Took off the number 2 oil pan, and fished out the shim from the far recesses of oil pan number 1. It was not all that bad, and the oil pan was leaking somewhat anyway.

The good news is that the loud ticking from number 7 valve is now gone, and the engine runs as smooth as silk. Replacing these shims is not such a big deal (provided you don't drop them into the engine), and within the ability of most weekend garage mechanics.

 

Awesome, good to hear ya got it out and you got rid of your oil leak in the process. I need to adjust my valves too b/c my #7 is getting pretty loud. I'm also glad to hear it's not a big deal, ( I've been putting it off for a while) but I'll be smart enough to plug all the holes first.

 

If you're doing the number 7 end shim, I'll give a few tips, because it is a royal pain in the a** to work on. You may have to move the gas line out of the way, which will require removing the pulsation damper. There are 2 crush washers (gaskets) on the pulsation damper that are not reusable. Part numbers are 23232-41081 and 90430-12005 (to 05/91) or 90430-12026 (after 05/91), and you can get them from Toyota.

The other tip is getting the shim out, as at the end of the cam there is only a small extension on the camshaft to push the valve down. This is easiest with the right valve adjustment tool, but people also manage with a screwdriver (taped to avoid scratching). To hold the valve down so that you can remove the shim, insert the right tool (or another screwdriver) at a 45 degree angle as shown in the attached figure. There is room under the camshaft bearing, since otherwise it would be hopeless. I oriented the small blowhole on the shim at the bottom, blew some compressed air in (a duster can with the red straw works very well here), and fished it out with a bent paper clip (a dental pick works well too). Once you get the shim out, leave everything alone so that you can pop the replacement shim in when you get it. You don't want to have to set everything up again.

 

Hey blunden, thanks for the tips. Every little tip helps from someone who has done it. I should have done this when I did the valve cover gaskets a while back (when I bought the car) but I didn't think it was necessary at the time. I have the manual to help so I'm not going in blind. I love those part number pics, is there a site where I can get those? Thanks again for the tips.

 

I used a Snap-On plier and stopper kit that works like a charm once you get used to how it works. I found pulling the exhaust cams is the easy way out for the exhaust shims, but you MUST retension the scissor gear with a 10mm bolt and unload it once it's back home.

 

www.lexuspartsnow.com is where to find the parts diagrams for your model and year. It is a great resource.

 

Blunden, how loose was the clearance on your number 7 valve? According to forum member Amskeptic: "If you have valve clearances that have opened up by .008" to .010" then you have a lifter bucket failure in progress. The valve stem will drill itself right into the lifter. This is common with sludgy engines, and there is no true cure but to pull the camshafts and replace the lifter buckets that have a dot depression right where the valve contacts it."
https://www.clublexus.com/forums/ls4...e-tapping.html

So I wonder if your number 7 intake valve will stay quiet for along time or if it might soon get noisy again because the valve lifter might have a dot size wear depression in it right where the valve contacts it the depression might continue to enlarge over time?

 

It was off by quite a bit. I had it measured at 0.016" instead of 0.008", but when I put the new shim in the clearance was slightly less than 0.008", so I probably was at 0.014" instead. The old shim was exactly what it was supposed to be, so no wear on that. It's possible that there are deeper problems, but I am inclined to wait and see if another noise develops. I'll watch for it though, thanks. For the moment I am enjoying the quiet.