Looked through the old posts and nothing. Is an 07 with the 3.5L an interference engine or not? Asking as wife's car now has over 100,000 miles on it and am assuming the timing belt may need to be changed. Also, if you have had the timing belt changed, how much did they charge? Last time I had it done was on a Toyota 4runner, but I also had the water pump changed at the same time. Was over $800, but I lived in Alaska at the time.
Interference or not
- Thread starter driggy
- Start date
- :
- 2022 CX-5 Turbo
CX9 has timing chain, not belt.
No need to replace the chain unless it is causing problem such as unbearable noises.
Replacing water pump on CX9 is a big job. Mechanic needs to lift the engine to get the job done.
It will cost you $$$. Replacing water pump is not on maintenance schedule. You can do preventive
if you really don't want your wifget stranded, especially in Alaska.
At 100K, it is not a bad idea to have the entire cooling system inspected (hoses, thermostats, coolant tank, etc.)
plus spark plugs, and many other stuff. That is, if you intended to keep the vehicle for a while.
No need to replace the chain unless it is causing problem such as unbearable noises.
Replacing water pump on CX9 is a big job. Mechanic needs to lift the engine to get the job done.
It will cost you $$$. Replacing water pump is not on maintenance schedule. You can do preventive
if you really don't want your wifget stranded, especially in Alaska.
At 100K, it is not a bad idea to have the entire cooling system inspected (hoses, thermostats, coolant tank, etc.)
plus spark plugs, and many other stuff. That is, if you intended to keep the vehicle for a while.
- :
- 2010 Mazda CX-9 GT Dolphin Gray
Are you maybe asking whether the engine is freewheeling? IOW if the valves and pistons will kiss if the Timing belt snaps? As Ceric states our cars have timing chains which *shouldn't* break. That said I'm not sure if the engine will freewheel in the event the chain ever snapped.
http://en.wikipedia.org/wiki/Interference_engine
"In interference engine designs, regular belt or chain service is especially important as incorrect timing may result in the pistons and valves colliding and causing extensive engine damage and therefore costly repairs. The piston will likely bend the valves or if a piece of valve or piston is broken off within the cylinder, the broken piece may cause severe damage within the cylinder, possibly affecting the connecting rods. "
My previous 3 cars (Honda/Acura) used interference engine designs - it was critical to make sure the timing belt was replaced on schedule to avoid the description above
In a freewheeling engine, if the belt/chain breaks, the pistons/valves don't collide causing catastrophic engine damage.
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- 2022 CX-5 Turbo
Antonio, I think you got it.
I was wonder what the "interference" means.
With high compression ratio (10.5?) of CX9's engine, the piston probably will bent the valves if the timing is off (broken chain).
That is why timing chain is getting popularity.
It will be a costly repair if all valves are hit by pistons with timing off.
With lower compress ratio, this is less likely by design.
Honda engines typically have this issue. Costly repair if you try to save $$$ on replacing belt. Good luck.
Newer Honda engines are also using chains now instead of belts.
I was wonder what the "interference" means.
With high compression ratio (10.5?) of CX9's engine, the piston probably will bent the valves if the timing is off (broken chain).
That is why timing chain is getting popularity.
It will be a costly repair if all valves are hit by pistons with timing off.
With lower compress ratio, this is less likely by design.
Honda engines typically have this issue. Costly repair if you try to save $$$ on replacing belt. Good luck.
Newer Honda engines are also using chains now instead of belts.
I know this is slightly off the subject Mazda wise, but in the not so recent past I owned a Toyota Avalon with the 3.5 that was of the free wheeling design. Even so, I replaced the timing belt at 100k intervals. Drove it 264k until traded for the 9. On the other hand I also owned (still do) a little pickup with a 22R motor. It has a timing chain. Care to guess which one broke?
Yeah well, how old was the truck when it broke?
They stopped making the 22R like 15 years ago!
