6 Attachment(s)
VVT internal inspection picture collection
Ok, so I had a VVT unit lying around (thanks @2XS) form an early model CX-7 and thought it best to be pulled apart and viewed to our forum! The complete history of this engine is unknown but from what I believe a VVT issue was not on the cards and the K's unknown however the internal parts of the engine showed minimal wear so assuming low K CX-7 that over heated for unknown reason.
As it goes early model MPS6, CX-7 and MPS3 have been known to get "rattle/ticking" on start up this is covered by a TSB not covered in Australia.
Here are some pics of the VVT unit!
Pic 1 is the complete unit
Pic 2 is the gear removed from VVT body
Pic 3 is the Body assembly (outer housing bolts to cover and gear, inner section is secured to camshaft, not the allowable movement between the two parts)
Pic 4 is the inner section only
Pic 5 is the effected area of failure
Pic 6 is the locking pin that locates into the detent (pic 5)
This unti had roughly .020" back lash and as shown in pic 5 the amount of wear on the surface leading to the detent of which the locking pin loacates into. This part is not much worse then the VVT from my own engine which had only 43000k.
As far as I know the VVT noise is caused by this pin not been able to lock in correctly on start up resulting in the rattle or ticking noise, this fix for this is a revised unit from Mazda or DCR both of which have had heat treatment processes to improve the wear resistance.
I have another unit that I will inspect and post when I can be arsed :p
