Hi everyone!

I bought a used 2007 CX7 almost three years ago with about 45k miles on it. I currently have 115k miles on it (I drive a lot for work) with no major issues. I've always heard an barely audible intermittent ticking sound that is more consistent at higher RPMs. However, the ticking noise never really bothered me as I usually have the radio on.

I eventually did receive the Mazda warranty extension for the timing chain to 70k, but I was already at 87k at the time. So I didn't do anything about it. I didn't realize the extend of this issue until I researched it online and found out how many unhappy customers there are out there experiencing stretched chains, timing in retard, some with major engine issues. But I haven't experienced any of this.

My dealer keeps reminding me each time I bring my veh in for an oil change to get the timing chain changed for $1000+ ($700 labor, $300 parts). However, when I asked if the chain will eventually break, the service guy says no, it is just a noise. I have no idea if this is true or not. I would not spend $1000 just to get rid of a ticking noise I barely notice and risk the service creating other engines problems. On the other hand, if the chain will eventually break, I would be willing to get the chain replaced now if it means avoiding a serious $8000 problem later (although I've read others had the chain replaced and the noise came back).

Thus, I would appreciate this forum members' advice. Should I change the timing belt or not? Thanks!

 

The problem isn't just the chain it's also the vvt gear. That's the variable valve timing gear on the intake camshaft that is drive by the timing chain. This problem will get worse and the chain will eventually break. If the chain does break then the valves in the head will need replaced. I've done more of these chains and vvt gears then I care to count. My recommendation is to have the chain and vvt gear replaced before it does break.

 

racer662009,

What exactly is the issue with the chain and the vvt gear? Is it chain stretch and worn teeth? Also, is the ticking noise the chain hitting the cover? Is $1100 reasonable for this type of job?

BTW, I have the 2.3L turbo if it makes any difference.

Thanks for the feedback.

 

The issue with the chain is just that over time it stretches and starts hitting the valve cover. The problem with the vvt gear is that it is hydrolic and the locking pin is supose to lock the gear to the housing on the vvt gear but they go bad and take a few seconds to engage. When it gets really bad the pin will completely break out of the vvt gear. $1100 seems slightly excessive. It's only a 5.5 hour job. 3.8 when it's done under warranty.

 

In my 8 years working on Mazda's I've never seen a timing chain snap.

The L3_T ( 2.3 turbo) engine is well known for noisy timing chains and rattles on start up.

When we have trouble with them we replace the chain, tensioner & variable Valve timing Actuator, just to remove all possible problems.

 

In the 10 years I've been a master tech for mazda I have had 3 cx-7's with broken chains.

 

Thank you everyone for your advice. I will look into getting the timing chain replaced.

 

Here in Canada, there's a TSB about the VVT actuator. Warranty was extended to 7yrs/140000km.

My 2007 GT was getting louder and louder (ticking sound, especially loud on cold starts). Took it to the dealership at 139000km and had the work done under warranty.

Now, it purrs like a kitten... So much nicer! It's like a new vehicle!

 

I just had my 2007 CX 7 break down on a major highway while going 100 km an hour in the fast lane. Luckily was able to get over to shoulder and get towed to dealer. We just had VVT replaced in Dec 2014 for $1500. Now it looks as though timing chain busted. I've had it with this car. What are my choices? I've heard lots of users say not to have it fixed as problem will re-occur. I can't sell it with broken chain. So frustrated that we got stuck with this lemon of a car!

 

1st of all my condolences to you & your engine.
The new chain shouldn't stretch as they have been modified & strengthened.
I've never had one of these chains so I am unaware if there is damage caused to valves, pistons & cylinder heads. I would of thought the chain would of been inspected very carefully when the VVT actuator was replaced.