I'm hoping someone here can get me some help. I'm working on a 3.0 V6, cyl. 3 had 0 compression, so I checked the clearances on the valves and the exhaust side was WAY too tight. Could not fit a .02 feller gauge in there. So I went with the smallest shim that we could buy from Toyota and still could not get any feller gauge in there, thought that was kinda strange, however did a compression check with that in there and it was around 100 PSI, not great but better than 0. So I wanted to see how it ran, started it up and it has the loudest lifter tick I have ever heard.

So that tells me the clearances are too much, however I could not fit any feller gauge between the shim and cam lob.

Anyone know what I could do? Besides taking it all apart and getting a valve job. This was after a head-gasket job also.

Thanks for the help.

 

Could be a bad valve. When I did my head-gasket job, I had the valves done (you should have too), and needed to replace three exhaust valves (they're not expensive, if you catch them when they are out anyway).

If the valve (or seat) is wearing away, the valve sits down farther decreasing the lifter clearance. Since the valve doesn't close all the way, you get no compression. Using a very small shim allows it to close "most" of the way, but it's only going to get worse.

I can't explain the loud "lifter tick," but if the valve is bad I can't predict much about noises.

 

Im having the same issue with my 93. Did a full rebuild, had the heads completely worked and now my intake valves are all way tight again. Re-shimmed them a couple month ago and there already doing it again. I'm completely stumped. Shows no sign of running lean. There past the point of re-shimming them now so where back to pulling the heads again.
If anyone has any advice that would be awesome.