Question on Timing Belt Slap

[Daninski]

Under acceleration and deceleration or even normal conditions how much belt slap would you expect to have, anyone? My friend has gone through 3 belts in 80k and he's beside himself as to the problem. I told him his tensioner is probably no good. He claims he can see a lot of belt slap (his covers are cut open).

[Tollis]

Are his covers cut open in a way that there going to cut the belt?

[jaydog5678]

Get a new tensioner. The T belt is supposed to last 70k and should be tight.

[mazdags94]

...or an over-torqued tensioner pulley? I bought my mx3 with 165k and by the looks of the belt, I'm convinvced it's the original one... belt was tight and was not off at all (I still replaced it though).

[Daninski]

Thanks

[wytbishop]

You can’t really over-tension the timing belt on the K engines. The tensioner pulley just pivots...it’s the tensioner cylinder that creates the force on the belt and It’s just a hydraulic spring. I would say that if the tensioner is tensioning as it should there would be very minimal movement in the timing belt. I would also inspect all the sprockets and pulleys to make sure that something sharp like a burr or weird edge isn’t damaging the belt. Do you have an example of one of the belts that broke? If I could see how it broke it might give a clue as to why.

[mazdags94]

I was referring to the bolt that holds the pulley to the block. If that was too tight, it wouldn't pivot like it should. It's not very likely but it was just a suggestion.

[davmac]

0 Tbelt slap - if the tensioner is working. The tensioner pulley should also be impossible to overtighten. The original bolt is a shoulder bolt with only threads at the end to anchor it on the front the engine but solid the length of the pulley so it can pivot. If someone put a different bolt in the tensioner pulley - now that might cause problems ...