Fixing large (1.7mm) valve clearance?

[cpreston]

I am checking/adjusting valve clearance on a 2000 1MZFE engine (Camry engine; happens to be in a Sienna). 23 or 24 valves are in spec, or close enough not to bother (the worst was .04mm off). But one has a gap of 1.7 mm!

Since the largest shim that Toyota sells is 3.3mm, I can close the gap by only .47mm with stock shims, which is nowhere near the 1.35mm I need. I need a total of 4.28-4.4mm (2.93+1.7-.35), I was wondering about using a 1 mm shim with a 3.3mm shim on top of it. Is such a thing ever done? (The ring that holds the shim in place seems to be about 2.8 mm, so I don't see having two shims causing the shim to pop out as long as the first shim was short, like the 1mm shim I'm looking at using.) I was also wondering if there's anywhere I can get a 4.3mm shim online.

You may be wondering about why there's such a big gap. I've examined the cam, and I find no rough spots or anything obvious and replacing the camshaft is even more work and another $200 part -- and I have no guarantee that the camshaft is the problem. It could be a deeper problem in the head that I'm not sure I want to tackle.

Thoughts?

[96paseo]

Did you measure the cam lobe and compare to the others? Even if there is no signs of cracks or pits, that particular lobe may have worn faster than the others, which could mean a problem with the lifter and/or valve spring. Another possibility is that particular valve is not fully closed and is throwing off your reading. That could be due to a warped head/valve seat, bent valve stem or a weak valve spring.

[cpreston]

I have not measured the cam lobe, as I don't have a tool to do that. I suppose I could look into renting one.

If I measure and it's the same as the others, what then? Am I looking at replacing that valve? How much more work is that? (I'll be pulling my Haynes manual out in a bit.)

[96paseo]

First thing to do would be remove the cams and pull the offending lifter. The tool you'll need is a micrometer to measure the lobe. Next would be measuring the lifter outside diameter to see if its within spec. At this point you can also check the spring retainer and keeper for damage. Doing a compression test on that cylinder before removing the cams may help indicate a sticking valve. How was the engine running before you went in to do the service?

[73sport]

hey, i'm not sure about the mechanical changes from 95 to 2000, but you might want to read this. I had the same problem and fixed it by adding a shim as there was no factory shim to make up the difference.

Some will say I'm nuts and should have pulled the head, but the compression on the 162,000 mile engine was only off by 6lbs per cylinder so I left the head on and added my own shim to make up the differene.

Read this. . .

Who has Successfully Adjust Valve Lash 1MZ????
Who has Successfully Adjust Valve Lash 1MZ????

I'll try and restore the missing links and fix the missing pictures.

PS - It had 162,000 miles on it then. It has 206,000 miles on it now and all is well. I run the cr@p out of this little V6 and it hasn't spit out the shim 0.4826mm (0.019") which I added under the factory #17 shim.

Measured: 0.31" (0.7874mm)
Spec is .014" (0.3556mm)
Difference: 0.017" (0.4318)

So I made a shim from 0.19" stock and added it under the existing shim.
Give it some thought and do some research on your engine. On the 95 1MZ the lifter bucket has suffcient depth to retain the factory shim while adding a 0.017" shim under it. I bought a lifter bucket from Toyo so I could measure it and fit my shim stock under it. This was very helpful. I'd recomend it so you get a good visual of what you intend to do. Well if your engine even allows this type of thing????

best of luck and I'll check back and see. (Although its been months since your post).

73Sport

[73sport]

Hindsite says a 1.7mm would VERY NOISY! That's .067"

Mine was .031" (0.78mm) and I corrected it. Your's being twice as far out must be really LOUD! Something else is wrong OR perhaps your measurement is in error?

Tell us what you used; was that cylinder at TDC when checked it, and how long has it been this way? If your measurement is correct, please disreguard the above post as it cannot be fixed in that manner.

Please check it again and tell us everything. . . (if you ever see this post that is......)

73Sport

95 V6LE @ 206K