I had to take my timing chains (one master and two connecting each V6 sides' double cams) off on my 2007 V6 Tacoma to reach to replace my head gaskets.

While I do have relatively specific instructions how to assemble them back together, is there any definitive test (e.g. by turning the crankshaft and observing the cams turning) that I can perform to make sure I did it right before closing the engine and putting the liquids back in, as to avoid having to reopen it (many hours of work) in case I messed it up?

  • 2
    You do not want to turn the crank on an interference engine unless you're sure that the timing is right (timing lines/notches line up). The risk is valve or cylinder damage from the two touching each other if timing is off
    – Zaid
    Jun 29, 2015 at 20:47
  • 2007 V6 Tacoma. updated the question
    – amphibient
    Jun 29, 2015 at 21:41
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    I don't know which instructions you might be using, but these are very comprehensive. If the colored links are still there and everything lines up, you should have nothing to worry about (though I know I worry about it as well). Jun 29, 2015 at 22:01
  • that's a great document
    – amphibient
    Jun 29, 2015 at 22:05
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    This is not an interference engine. The valves will not make contact with the pistons if the timing chain were to break while driving. You can turn it over before you put the timing chain cover on and hand crank the motor at the crank to check your work and verify everything is lined up proper. Best of luck! Have fun. Jun 30, 2015 at 0:49

1 Answer 1


The best way to test to see if your engine is timed correctly is to rotate the crank shaft through 720° of rotation then check your timing marks again. Since you (supposedly) have a non-interference motor, you will have no worries. If the marks line up again, then you're golden. You'll want to do this with a crank snout socket or put the harmonic balancer bolt back on to turn it. You don't want to use the starter. Make sure the spark plugs are out to ease the turning.

If you did have an interference motor, you can still do the same thing. The only difference is, if you feel any resistance at all STOP TURNING THE CRANK. That's why it's important to leave the spark plugs out, other wise you'd be feeling the compression resistance and not realize it if it were interference resistance. If you did feel resistance, you'd want to turn the crank backwards to the point where you started and then double check your timing marks. More than likely, though, you'd find they would match up to where they were supposed to be at that point.

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