Common faults with the Mazda CX7 have been covered with previous articles which can be found here.
One that we have not yet covered off is the noisy engine fault that develops in the 2.3 litre engine.
Lack of lubrication harms many engines however skipping services or ignoring oil leaks from the oil coolers (a common fault) can cause these engines to do serious damage to both the timing chain assembly and the cam phaser, also known as the VVT cam shaft adjuster.
The noise that develops sounds like a noisy timing chain and that will need replacing however the first component to fail is the cam phaser. If you replace the timing chain, guides and tensioner but fail to replace the cam phaser you will have the same noise you started with.
This job does require speciality timing tools as there are no timing marks on the cam or crank pulleys. you can get away with replacing just the chain by making your own mark however the cam phaser has no key way so when yo replace that, you will lose your cam timing.
Don’t skimp, buy the timing tools, if you get this wrong you will bend valves.
When this fault occurs you may get a check engine light and a fault code for camshaft timing over advanced. This will help you diagnose whats actually wrong.
Cost of this may vary depending on the quality of cam shafts you buy however we advise always buy the cam phaser genuine from mazda. The does retail for around the $400 mark but its not something you want to be cutting corners with.
Along with this part the timing chain kits can range from a few hundred dollars up to $1K if you buy the genuine product from mazda. Add to this a minimum of six hour labour and your unlikely to see an change from $2K.
This fault is mostly avoidable by keeping your servicing up to date. Don’t ship services, keep you engine internals well lubricated and you will not see this fault.