2004 to 2020 Mazda 3 Forum and Mazdaspeed 3 Forums banner

Timing belt/chain

1 reading
101K views 4 replies 5 participants last post by  gregersonke  
#1 ·
I can't find this so thanks for any input available. I've got the 2014 3i GT hb with the 2.0 engine of course. In the old days they used to say change a timing belt at 60k and a timing chain at 100k to avoid the possibility of shredding the engine if it failed. So, does the 2014 2.0 have a chain or belt and what is the correct interval now for changing them?
 
#3 ·
The Skyactive 2.0 and 2.5L engines both use timing chains. Neither one has a recommended service interval noted for them in the owner's manual of factory shop manuals.

WRT timing belts, my advice is to just replace them at or before the maker's recommended service interval - ESPECIALLY if the engine is an interference type (i.e., belt failure results in valves smacking pistons). If it's a non-interference engine, you can let the replacement slide a bit, understanding that you're taking a risk of being stranded somewhere if/when it fails.

Had a timing belt fail about 10K miles short of the recommended 60K replacement mileage in my ex-wife's late 80's Ford Escort (THAT car was total crap!); fortunately it was a non-interference engine. OTOH, when I changed out the timing belt in my previous daily driver, an '03 Mazda Protege5, it looked brand new. In that case, the manual said to change it at 110K miles, and I did the job at about 105K miles. That car is still running great and being used by my sons now.

WRT timing chains, I don't recall any that have a required replacement requirement. Usually there is just a recommendation to inspect them for wear and excess slack, and only replace if they are out of spec.
 
#4 ·
As noted above it's a chain. Unless there's a manufacturing defect it should last the life of the car (couple of hundred thousand miles).

As far as belts go, with non-interference engines (like my Protégé that the 3 replaced) you can pretty much let them go to at least the maintenance interval. Modern belts are well made and there's no risk (other than being stuck waiting for a tow if it breaks) in letting it fail on its own. My Protégé was at 150k and almost 13 years on the original belt and it looked fine. I ignored the interval of 105k. My Miata (also non-interference) is 21 years old and has 78k on the original belt. I'll probably swap it out this coming summer just because it is finally looking a little old. On an interference motor (like Hondas have -- their V6 still has a belt) I'd probably not go past the recommended interval. Valves crashing into pistons at 7000 rpm is uhhh... bad.
 
#5 ·
The belt on my honda minivan, I let go about 20k beyond the interval before I replaced it and it still looked good. Generally with belts it depends on the environment. If it's in dry areas replace at or before interval. In the mild to humid areas you can go a fair bit beyond the interval. As for timing chains, I usually say around 200-230k.