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My Mazda3 GS 2.0 6spd Manual has developed a metallic rattle in the first minute of warmup. I asked my regular Mechanic to listen for it and he suspects it is Piston slap and suggested the best fix is to sell the car in the summer... :rolleyes:

I made a video where i start the car at below freezing temperatures with the phone located on the battery under the hood. I split it into two sections where the first 20 seconds is where you can hear the engine and injectors clearly but the rattle (almost like a bolt in a thick tin can being shaken) is in the background. Compare that to the second half of the video where it is not present since the engine at this point has been running for 3 mins.
Video:

Let me know if you think this is Piston slap or something else, thanks in advance

2014 Mazda3 GS Conv Package
6 Speed Manual
245,000 km
 

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Wonder if that's a "tired" hydraulic "lifter"? Sky models have a distinctive and noisier first ~ 30 secs (this varies based on ambient temp) while exh valves are purposely held part-open to heat up pre-cat faster.

Others?

If it's a lifter, then trial with a chemical means of freeing it is the first step. Also, frequent-enough oil changes and thin-as-Mazda-allows oil - 0W-20? oil? Real PITA to get to lifters and you'd automatically change all 16... and mebe timng chain + sprockets...?

Or, just live with it?

My old Corolla has piston slap as does my old Civic EX. Varies based on load if I drive them during said occurance.
 

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All 14's are Skyactiv. The rattle is audible but so much quieter than the injectors that it seems unlikely to be piston slap. These are complex engines, and on a cold warmup they do some funky tricks with the valve timing to get it hotter faster. I don't necessarily hear anything that concerns me. My '14 makes different noises on different days, but none of them concern me

Engines have hundreds if not thousands of moving metallic parts and hundreds of explosions per minute happening in them, noises are bound to arise. Unless the rattle becomes louder and louder as time goes on, don't stress yourself out by leaning an ear in all the time.

Fresh oil and long drives make engines happy. Don't go looking for a problem that isn't there.
 

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2012 Mazda 3 GX MT5
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Here is answer from google :
Piston slap in itself is not harmful - after all it is just a noise and all engines make lots of noises as a result of different clearances, varying lubrication rates, harmonics & pulsations, etc. Audible noise is emitted by vibration and the noises we hear have to be within the human audible range; some are not.

I figure is it were serious you would hear it when engine is hot or cold and performance would suffer drastically...burning engine oil ...
With age / high KMs that gap gets wider..microns wider with wear. Consider a thicker oil ... I went from 0w30 oem mazda oil to 5w30 Molgen cuz my Mechanic suggested that to compensate for wear n tear loss ...Im at 258K kms. With this oil I do let it idle a bit longer on cold starts and keep it under 3K rpm for a few minutes.
 

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Discussion Starter #6
Hey guys thanks for all the feedback and replies; Yes oil changes are very frequent per suggested Canadian guideline every 8,000 km and sometimes i let it stretch to 10,000km in the summer. For Oil I use mainly Mobil 1 Fuel economy 0w-20 with a mobil 1 filter. Ya I am wondering if this problem will go away once it warms up in the coming months or get worse...

Yes it is quieter than the injectors, however the noise is more noticeable in the car with the firewall attenuating the engine noise except for the higher pitch rattle but it didn't pick up on my phone so i didn't include it.

With age / high KMs that gap gets wider..microns wider with wear. Consider a thicker oil ... I went from 0w30 oem mazda oil to 5w30 Molgen cuz my Mechanic suggested that to compensate for wear n tear loss ...Im at 258K kms. With this oil I do let it idle a bit longer on cold starts and keep it under 3K rpm for a few minutes.
Do you happen to live in an area that gets very cold? I wouldn't mind trying in the summer but i would be worried about the thicker oil in winter.

I have a theory that this premature wear maybe self inflicted since this is a Manual transmission and I strive for the best fuel economy I tend to place the engine in a Low RPM High Load state more than a automatic transmission. I'm obviously avoiding this now but i think it maybe too late.

Any tricks to rule out or pinpoint piston slap? Would the cylinder with piston slap read a lower compression?
 

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Hey guys thanks for all the feedback and replies; Yes oil changes are very frequent per suggested Canadian guideline every 8,000 km and sometimes i let it stretch to 10,000km in the summer. For Oil I use mainly Mobil 1 Fuel economy 0w-20 with a mobil 1 filter. Ya I am wondering if this problem will go away once it warms up in the coming months or get worse...

Yes it is quieter than the injectors, however the noise is more noticeable in the car with the firewall attenuating the engine noise except for the higher pitch rattle but it didn't pick up on my phone so i didn't include it.



Do you happen to live in an area that gets very cold? I wouldn't mind trying in the summer but i would be worried about the thicker oil in winter.

I have a theory that this premature wear maybe self inflicted since this is a Manual transmission and I strive for the best fuel economy I tend to place the engine in a Low RPM High Load state more than a automatic transmission. I'm obviously avoiding this now but i think it maybe too late.

Any tricks to rule out or pinpoint piston slap? Would the cylinder with piston slap read a lower compression?
I live in Toronto ... Im on the 5w30 Molygen in the winter no issues ...
 

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Seems to me, in 2012, both a Skyactiv-G 2.0 was available, 155 hp, and a non-Sky 2.0... 148 hp.

Others, am I right?
Yes, the first 155 hp 2.0 SA-G motor was made available in North America when the Gen 2 was updated in 2012. The other 2.0L motor for 2012 was the MZR based engine, rated at 150 hp or 144 hp for the PZEV version. I don't think the PZEV was sold in Canada though.
 

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Any tricks to rule out or pinpoint piston slap? Would the cylinder with piston slap read a lower compression?
You can use an endoscope through the spark plug hole and look at the cylinder walls. Excessive piston slap will scar the walls long before you have a loss of compression. As a former kia owner, I'm very familiar with piston slap issues. My last car sounded like a diesel by 70k miles, even when warned up.
 

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Would someone confuse piston slap noise with Direct injector noise (Tick noise)?
I was told age of your injectors will emit a similar noise to a belt tensioner noise issue ... and what else sounds the same?
Is piston slap a bell sound?
 

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I've only heard that loud injector tick noise from DI diesels. I wouldn't say piston slap sounds like a bell, more like rattling a can half full of pebbles.
 

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I've only heard that loud injector tick noise from DI diesels. I wouldn't say piston slap sounds like a bell, more like rattling a can half full of pebbles.
No peebles in mine...she is a bit tick tick tick when she is cold...but purrs after that....

I would assume increased oil consumption with piston slap
 

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My Mazda3 GS 2.0 6spd Manual has developed a metallic rattle in the first minute of warmup. I asked my regular Mechanic to listen for it and he suspects it is Piston slap and suggested the best fix is to sell the car in the summer... :rolleyes:

I made a video where i start the car at below freezing temperatures with the phone located on the battery under the hood. I split it into two sections where the first 20 seconds is where you can hear the engine and injectors clearly but the rattle (almost like a bolt in a thick tin can being shaken) is in the background. Compare that to the second half of the video where it is not present since the engine at this point has been running for 3 mins.
Video:

Let me know if you think this is Piston slap or something else, thanks in advance

2014 Mazda3 GS Conv Package
6 Speed Manual
245,000 km
Maintenance- Has the timing tensioner or guides been replaced yet?
 

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Maintenance- Has the timing tensioner or guides been replaced yet?
Not Mine.
When i upgraded to lightweight pulleys i replaced the belt.
 

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Maintenance- Has the timing tensioner or guides been replaced yet?
If you talking about the timing chain.
It was checked when the cams were upgraded.
Tension was good , everything looks good. At one point thought camgears were misaligned.
tik tik tik sound remained the same at idle or higher rpms
 

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Highly unlikely that you have piston slap with a skyactive, highly... more likely that you have carbon build up than piston slap. Try the lucas top end cleaner, by the time you get through 3 tanks you should notice a difference finish the bottle and you'll be a happy camper for a long while. . https://www.amazon.com/gp/product/B000ARPVOI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Hey Greg
are you saying carbon build up on the injectors is causing the sound on the newer engines?
 

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Hey Greg
are you saying carbon build up on the injectors is causing the sound on the newer engines?
A lot more likely than piston slap. Especially after 150k miles. Very likely there is a little bit of buildup there and the system in general. Not a lot, but just enough that it runs a little different than you remember it running. The trick is, that cleaning off the top end injectors, valves etc. works better over several tanks hence the larger lucas additive bottle works very well for this. After 3-4 tanks the car will run a lot closer to what it did when new.
 
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