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1997 Mazda MPV Question: Timing mark bounces back and forth, will not stay steady.

 

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fix it guy, 3.0L V6, Lakewood, CA, April 17, 2011, 14:26
 Rookie

I just finished changing the timing belt and replacing the head gaskets and cam shaft seals. The timing mark vacilates from 10 to 12 degrees and used to stay steady on 11 like it should. There is a noise like a vacuum leak, 'tick tick tick,' but I can't find it, checked all air lines and sprayed carburetor cleaner on all hose connections and no change in engine idle.

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  • Answer #1

    Superbob April 18, 2011, 11:32
     Master

    I think that the ticking noise is an exhaust leak, check that. That the distributor timing fluctuates 2 degrees makes me think that the belt tension is not constant and maybe the tensioner is faulty and the belt is not running tight enough. If you run the engine with the timing covers off you may be able to see if the belt is tight enough or if it's flapping (for lack of a better term) and causing the timing to oscillate. The tensioners on these engine were a source of trouble sometimes, they would lose their hydraulic oil or bind up.

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    fix it guy, July 22, 2011, 18:18
     Rookie

    Thank you very much for your answer. Yes, the timing belt was loose, vibrating a lot, the tensioner was bad and I replaced it and the worn belt and pulleys, and it ran smooth. The timing mark fluctuates a little but normal, according to my mechanic friend. I used it for my vacation, put 2,800 miles on it and it was fine!

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