Valve clearance adjustment

sk66 · Post by **sk66** » Mon Nov 28, 2016 1:52 pm

The two manuals in the library have slightly different procedures. The 4G7/4D5 manual has a warm engine clearance procedure at .25mm, and a note to not let the feeler gauge touch the rocker pad... which makes little sense to me as that's what's being measured.

The 91-93 (mine's a 91) 4D56 manual has a cold procedure at .15mm and no note about the rocker pad. At the end it says warm it up and check warm clearances but gives no spec.

I did the cold engine procedure and all of mine were a bit tight. I adjusted them all to .15mm using the feeler gauge as I would on any other engine. Started it up and everything sounds good... that's where I left it. I don't know if I should warm it up and check for .15mm or .25mm... and if it's going to loosen to .25mm when warm I would think the cold measurement is more important.

BTW, for anyone following later... the manual(s) state to turn the *crankshaft 360* and then check the other 4 valves... that is NOT the same as turning the *camshaft 360*... that threw me for a minute as I could easily see/was watching the camshaft timing marks.

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Post by **Growlerbearnz** » Mon Nov 28, 2016 4:35 pm

Yeah... there's two different settings depending on year and application. Early engines with protruding valves are 0.25mm Hot, later engines with flush valves are 0.15mm cold.

On the underside of your engine cover should be a silver sticker on the passenger side. It's mostly in Japanese, but if you see "0.25mm" on it then your clearances should be 0.25mm when the engine is hot.

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Valve clearance is needed to give the valves room to move while still being able to close completely. Valves get longer when they heat up, and over time the valve seats wear away, letting the valves sit higher in the head. There's not a huge difference between earlier and later heads, I presume they went to 0.15mm just to make the engine a bit quieter, so I think you *should* be ok for a while at 0.15mm cold. but I'd still re-set it to 0.25mm hot at the next opportunity just to be safe.