Toyota 22R Losing Compression or Just Mis-Firing?

[Speed]

Hi Moses;

   Hey,on a 22R,what's the deal on milling the head? I think this engine might have a head gasket leak from #2 to #3 cylinders. It isn't transferring any fluids,doesn't show signs of leakage outside,but 2 and 3 seem to falter until about 2000 rpm,where it smooths out,but still lacks enough power to pull 5th gear with any degree of authority. STILL gets GREAT mileage though.

   Well,gotta sleep a little.

   Speed

[Moses Ludel]

Speed...A Toyota 22R cylinder head can be milled or even straightened if the bow is slight.  The latter is done with special fixtures and sometimes the addition of precisely controlled heat.  Milling by itself will not straighten the camshaft bearing bore alignment.  Bending back to straight can, and so does line boring the camshaft bearing towers and milling/boring the caps slightly.  Slightly is the operative word:  The timing chain/valve timing do change with milling or realigning the camshaft bore;  the cam sets lower in relationship to the crankshaft centerline.  This alters valve timing by shortening the distance between the camshaft sprocket and crank sprocket.  

Do a leakdown test on the 22R to confirm cylinder pressure.  On a four-banger, cylinder balance is even more crucial.  Recall my 22R engine condition concerns and leakdown test suggestion here at the forums in our 2015 discussion:

I like to post the diagnostic link/topic on leak down testing (above):  compression gauge versus a leak down test.  I have shared this at the forums many times.  Used creatively, a leakdown test is the most accurate way to assess engine condition short of a teardown.  A "poor man's" leak down tester can be made from an old spark plug shell (metal shell with all porcelain removed) brazed properly to an air fitting.  Gauges make it even better;  OTC sell a basic tester for around $55.

Moses