Intermittent Engine Knock?

[xsilent13x]

I just bought the 2010 MS3 only 300miles clocked on it right now and I'm getting intermittent engine knock/rattling. I was in a drive-thru at Dunkin and I noticed it on and off. I know some vehicles have normal engine knock like the LS1 chevy engines but I didn't know if ours was one of them.

 

[8.5MS3]

how do you know its engine knock?

 

[xsilent13x]

how do you know its engine knock?

Sound is coming from underneath....kinda sounds like a 'spun' rod-bearing. Like the bottom of the rod is slapping the bottom of the oil pan. I heard a 'spun' rod-bearing from a STi and it sounds similar but not as bad. I'm afraid it'll get worse if I give some gas and the bearings get crushed. I'm a first time Mazda owner and I don't know the small details to these engines yet. I know that engine knock could be a lot of things (crappy gas/low octane, low oil pressure, wrong oil, lifter slap, etc). I'm probably just worrying too much and taking every little noise serious since its a new car lmao.

 

[8.5MS3]

More than likely its just the injectors. Youtube some engine sounds for intakes and listen before they rev up. The motor ticking is normal

 

[Dubcnea]

More than likely its just the injectors. Youtube some engine sounds for intakes and listen before they rev up. The motor ticking is normal

+1 i heard this on my '06 and this car as well. unless it's REALLY thundering, you're all good (2thumbs)

 

[coyfish]

Very doubful your car is audibly knocking at idle in a drive through. Your most likely hearing normal valve tick / fan which is pretty noisy.

 

[xsilent13x]

Thanks guys. I'll stop worrying about it.

 

[Dubcnea]

better safe than sorry!

 

[JS + MS3]

Nope.

 

[nynhex]

Doesn't sound like engine knock. Sounds like injector or valves doing their thing. Again without actually hearing it I couldn't say. To be safe hook it up to diagnostics if possible and look for any knock retard indication or see if it's hitting any codes.

Good luck and good choice on your car!

 

[MS3chriSS]

LS1's dont have engine knock from the factory. Its the injectors, same with this car. Have you ever heard engine knock? Its a much different sound.

 

[xsilent13x]

LS1's dont have engine knock from the factory. Its the injectors, same with this car. Have you ever heard engine knock? Its a much different sound.

I beg to differ.....I owned a 02 Camaro SS for several years and everyone even Chevy techs say they have normal engine knock UNDER the engine. They injector noise is quiet on LS1's compared to MS3's.

 

[GTXT23]

Knock-Smock These engines are bullet-proof monks the VVT system in conjunction with injector metering is going thru its normal break in stages and also gleaning imput from your driving habits to "self-tune" based on your habits . This can be cleared to new anytime but it is a good thing as it gets to know its "drivers habits" and reacts better and delivers better performance and efficiency . You will hear this intermittently for a while. situation "NORMAL" back to Devcon 0 - worry about something else- it aint a Rolls Royce jet engine

 

[King Of Cars]

My '93 has ~182k miles and it recently did the same thing. It really sounded horrible. I had it towed to a friends shop and put it on a lift. The sound was loud, but it was very hard to pin down to a location. It would come and go, and finally after about 3 hours of fiddling with it, I noticed alot of rust around a bolt head that fastened the p/s pump or alternator to the truck. Got a flashlight and saw that the bolt was loose. After tightening it up, we started the truck and the noise was gone!! All it was, was a brace hitting against the boss on the block.

 

[XspeedyD]

why worry with a new car? i'd worry with an old car. new car gets fixed for free.