Timing chain or Pulley noise?

[EdMazdaMan]

Hi all, I recently started hearing a strange clicking/ticking noise coming from either one of my pulleys or timing chain. I seem to hear the noise mainly on a cold start but it seems intermittent even when the engine has warmed up and especially under low RPMs (e.g. when running the a/c). I made a video of the noise https://www.youtube.com/watch?v=fq3lQ4sSA2k and wonder if anyone out there has heard something similar and what you did to fix it.

I did take it to the stealership but they didn't provide anything conclusive other than it might possibly be my timing chain. I have my doubts. Thanks for reading.

[thyNo0b]

its hard to tell by just listening to the video provided above. to me it kinda sounds like one of your pulleys, but I cant tell you how many 2.3 MZR DISIs have come into the shop with engine failure due to a jump in time caused by old timing chain, guides, tensioners, ect. it seems like they mostly happen around the 100k mile mark, but I've seen some with just 75k miles start having the noise of chains slapping. either way, id save up for a timing job just for the fact that I've seen many of our engines fail due to people not doing it before it's too late. there actually used to be a TSB I believe for the Gen1s for a chain rattle on cold starts, which would entail us replacing the timing chains, guides, tensioners, etc.

[EdMazdaMan]

Yeah, looks like if I want to keep the car I might need to bite the bullet and get the timing chain done. BTW, the car is right at the 100K mile mark. I am thinking that I'll pay to have it diagnosed to determine what the noise might be first.

[EdMazdaMan]

Well, I finally I know what the cause of the noise is. Turns out the alternator is starting to go and the belt tensioner is bad. Cost of the repair is almost 1K. I might try doing this on my own, so time to research how to's replacing an alternator. Sucks! Anyone do this before??

[SSinstaller]

There is no clutch in the alternator.

[Jeff23spl]

1k for tensioner job ?

The alternator has a one-way bearing on the pulley to be free while you let off go the fuel and i never had any problem with them while i had to replace some others.
i would start by replacing the 2 iddler pulley bearing. (tensionner and the fix one)
You can even replace just the center bearing for less than 20$ each if you have the skills to get the old out and press the new in. The one on the tensionner has a plastic rib to preven it from going out so it is easier to get the whole pulley but one can break the ribs and glue the new bearing in with locktite or similar.
once at it, the AC clutch bearing is also often falling out, i would check it with the belt removed...
At last, i would mess with the alternator but i would be surprised.... and you can have the bearing replaced if it charge ok, instead of getting a new one

[EdMazdaMan]

Seems natural that with almost 100K on my Speed the bearings in the pulleys are starting to go. Wish I had my own garage because I'd definitely look into replacing the bearings myself - I rent an apartment.

I am currently getting estimates from local shops so I can get the best deal. 1K is silly amount to pay. I am also going to ask the mechanic to see if he can repair the alternator instead of replacing it, especially if it is still charging good.

Thanks!

[Jeff23spl]

Originally Posted by EdMazdaMan Seems natural that with almost 100K on my Speed the bearings in the pulleys are starting to go. Wish I had my own garage because I'd definitely look into replacing the bearings myself - I rent an apartment. I am currently getting estimates from local shops so I can get the best deal. 1K is silly amount to pay. I am also going to ask the mechanic to see if he can repair the alternator instead of replacing it, especially if it is still charging good. Thanks!

as i said, replacing the alternator could be a second step because it is the hard to reach and costly part to get a good profit...
idler and tension is 30$ us each on Rockauto and can be replaced in less than an hour....with the belt removed it can be easy to check alternator or even put back the belt and start the engine to see if noise is gone....
You lift to remove passenger wheel
remove the splash guard
note the way the belt is installed around each pulley
bend the tensionner with a 14mm long tool to twist the tension (best with a solid tool not ratchet)
remove the belt
remove the tensioner (2x 12mm bolt) and iddler (1x 10mm bolt
put back new ones
put back the belt by using the long 14mm tool
put back everything else.
done.

[GohanX]

Originally Posted by Jeff23spl 1k for tensioner job ?

Mechanic probably took one look in the engine bay and said "what the shit?!?" The alternator is down in there, I hope I never have to mess with it.