[Rogue6]

I had to go to take 200 mile trip for work. Before I left I noticed the clack, clack sound that usually means it's time for more/new oil. Before I went I had mazda change the oil and filter (I didn't have time to do it) But when got the car back it was still making the same loud noise. I had to make the drive so I trucked along. I still got the same gas milage but this noise is getting annoying. It only happens from idle to 2k, then it stops. Anyone have any ideas?

 

[Mike 94PGT]

Friction Gear Spring

Clattering noise on the V6 from idle to 2000RPM is a sure sign of friction gear noise. The spring tension has probably gone, reducing preload and allowing the gears to rattle like hell.

Not much you can do about it except replace them. The front is fairly easy (remove valve cover, remove intake cam, replace spring & re-install.) THe rear involves the intake manifold coming off.

 

[gaios1]

The same happened to me about a year ago. No other choice other than replacing the friction gear(s). Total cost: $843.64CAN done by MAZDA. I have all the part #'s if you need them.

Later,
Peter

 

[Rogue6]

it sounds like a semi-truck

How long can I let it go like that with out causing any serious damage? I am trying to get my hands on a KLZE (but no one seems to have them in stock). I am selling the current motor in it to my friend and I don't want to screw him. Any sugestions?

 

[Mike 94PGT]

Actually, believe it or not, but the engine will last pretty much indefinitely making that noise. The whole idea of the friction gear was to reduce that clatter because it's so bloody loud. A camshaft presents a very uneven, unstead loading for a gear system and without the friction gear, the gears bounce back and forth on the backlash, which is what causes that noise.

History:
The cam drive gears have 55 teeth each and the friciton gear has 56. The friction gear literally rubs against the driven-gear and also meshes with the drive gear. Because the friction gear has one more tooth, it turns a bit slower than the driver-gear, causing a drag in the system that helps to take up the backlash in the helical gear system. The friction gear spring preloads the system, which is what causes friciton between the friction gear and the driven gear. Your spring has "sprung" and there's no or little friction.

So the engine will be fine making that noise and it's a purely aesthetic problem. You might try switching brands of oil...a 10W30 Mobil 1 for instance oif you aren't already using it, may help quiet the system but more likely you'll need to get the gears done.