Good Afternoon all,

I joined a bit ago in hopes of some guidance as far as maintenance as I was hitting 25,000 miles. Pretty much all I had done is routine oil changes every 5,000 and tire rotations. I never quite got there. Last thursday I was rolling along going about 35 and had started to ramp to 55 then felt a thud. Engine light came on along with a traction control light. The car had a rumble and had almost no power. I pulled over and had it towed. Today I got a call and they found the piston in cylinder 1 cracked. They have to replace all 4 pistons and rods, head gasket, camshaft cover gasket, pretty much a major rebuild. They said it is something called low speed preignition and sometimes happens with these turbo engines. I did a google and found hundreds of posts on Volkswagen, Chevy, Ford, etc but only a few posts on Mazdas.

Once I get the car back is there something I need to do to prevent this?

 

WOW! Well that really sucks. My 2021 Signature is coming up on 25,000 miles within the next couple of weeks and I must say this kind of terrifies me. Just read a Wikipedia article on low-speed pre-ignition (LSPI) and although it's somewhat rare, three statements made an impact on me: (copied from Wikipedia)

#1: LSPI is most common in certain turbocharged direct-injection vehicles operating in low-speed and high-load driving conditions.

#2: The issue mainly affects the U.S. car market as their fuel is of varying quality. The R.O.N. (Research Octane Number) is lower on Petroleum Distillate (Gasoline/Petrol) than the U.K.

#3: Researchers have been unable to pinpoint a single root cause for all LSPI instances.However, tests involving the use of engine oils have shown engine oils can be formulated to prevent LSPI while maintaining the oil’s basic performances.

Edited: This article touches on how motor oils can help prevent LSPI:
What is Low Speed Pre-Ignition (LSPI) and How Can It Be Avoided? - oilspecifications.org

I'm not sure what an engine oil can do to prevent the catastrophic damage that sometimes occurs with LPSI but I see where fuel octane can be a deterrent.

I would have been running 93 octane all of the time if gas prices hadn’t risen so much in the last year and a half, but more often than not I’ve been opting for 87 just to save some $$$.

I really was unaware that this was an issue at all on direct-injected turbocharged engines.

Anyone else with more knowledge about this want to add their $0.02?

 

Very unusual for Mazda corporate to authorize a warranty rebuild like this, instead of replacing the engine, because they don't have a lot of confidence in the typical stealership service department's ability to do the job properly. Not saying that yours will mess it up - it's just a general probability thing. Did they inspect the cylinder walls for damage with a cam? I'd expect that corporate would want to see pics of that inspection, as a requirement for warranty coverage of the rebuild.

 

Agreed with the conclusion about a generic engine rebuild... but the part that you are assuming all dealership do not have MAZDA certified or ASE certified automotive technicians on their employee. If so you would be MYTH-staken.LOL

 

Although it stinks, it sounds like an unusual occurrence. I can't think of a thing you could have done to prevent it, just be glad it happened while the car was still under warranty. I hope the dealer will check the engine sensors in case a fault of some kind caused the pre ignition. To be honest I've never heard of this issue before I'm sorry it happened to you,

 

Actually, there is so much information not posted... and yes if it were factual there would have been a ECU update with programing to change some fueling and timing (among a few things) that could have prevented that theorized occurrence.
What I read in the first post does not make since because there would have been a few DTC's I can think of that would have been generated if such engine occurrences were actually happening.

 

A bad piston is rare indeed. Mazda might not make their own pistons.
I've know of a GMC truck with a bad oil pump, Engine ceased with around 150 miles.
He got a new engine, then sold it.

 

Not sure about what you really are trying to say.
First it has been an industry known that many Auto manufactures use companies like TRW for engine parts like pistons. And the other you knew a guy story.... auh ok I knew a lot of guys..... LOL having owned my Performance Engine machine shop I heard all sorts of unconfirmed stories having to do with factory engine. LOL

 

I said it. No 'interpretation' needed. The company I worked for made some of their
own pistons when I first started there, but contracted them out some years later.
My point, if it slide over your head, was that a very rare part failure from the factory does
happen. I worked with the guy who got the new engine. Oil pump failure is very rare as is
a bad piston.

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ROLMAO nothing goes over my head.... Dennis..
And oil pump failure is NOT rare overall in the industry. LOL
And bad pistons... wow you must have worked for an interesting parts manufacturing company LOL . Even cast pistons had small failure due to inconsistent checks and balances on foundry production process but forged pistons almost never. And when it happened it was dozens not just one or 2 and they were generally caught before reaching the install of an engine.

Lets try to stay on MAZDA subject material and not other auto manufactures or aftermarket parts contracted by some auto makers, shall we? LOL