Just picked up my new CX-5. Got a bit of a shock when the cold start sounded more like a tractor than a car! I've read the comments about the cold start (1500rpm's), but wasn't sure if everyone else is having the same noisy startups that I am. My Mazda dealership says that it's normal, however it's hard to believe that a brand new car can be that noisy when it starts.
CX-5 Startup
- Thread starter markcx5
- Start date
this isn't the really good write up but it sums it up:
In order to help keep that 13:1 ratio, a series of twists have been added to the exhaust headers, creating a knot that looks something like an interchange along the I-5 outside of Los Angeles. The extra curves are given to the pipes so that heat and exhaust flow can be better managed. Since the flow takes a little longer to charge through the system on start-up, fuel is fired more quickly into the combustion chambers, which is what you’re hearing.
In order to help keep that 13:1 ratio, a series of twists have been added to the exhaust headers, creating a knot that looks something like an interchange along the I-5 outside of Los Angeles. The extra curves are given to the pipes so that heat and exhaust flow can be better managed. Since the flow takes a little longer to charge through the system on start-up, fuel is fired more quickly into the combustion chambers, which is what you’re hearing.
Thanks for the info. I was preparing to call my car dealership and give them a blast, but it looks like it's a legitimate thing so I'll save myself some embarassment. I'll stop stressing about the startup noise and concentrate all my energies on the TomTom voice recognition (or lack therefof), but that's a whole other story!!!
Does this occur on the first really cold start in the morning or every time you start the engine? Maybe Mazda will figure out something to quiet the engine down since people are complaining. I know my CX7 make injector noise and I get tired of making excuses for it so I can imagine what a CX5 owner will go through with a noisy startup and it wont be fun. 
)
)I got my CX-5 back in March when it was still fairly cold in the mornings. I usually get into my vehicle at 0615, so it's dark and cold. Back in March we had some cold mornings around 40 degrees F. The engine is louder for about 30-45 seconds. I really don't mind much, but during about 3 of those really cold-weather starts, it seemed to be miss-firing or something where the RPM fluctuated intensley between 500-1500. I was really concerned and called the dealer, but it never happened again (I think because it finally warmed up). I'm nervous about this winter season, if it happens again I'm calling the dealer straight away. I should find out in October/November time-frame.
Suddueth13
Member
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- 2011 Mazda 2 Sport, 1987 Mazda RX-7 Turbo II
It's the same for the Skyactiv 3's as well. It's not so much the engine you're hearing but the primary catalyst being warmed up. It's usually no more than 30 seconds and is normal for the Skyactiv vehicles.
exactly, once I knew it wasn't the engine clattering around due to lack of oil I was fine with it.
Same here, very noisy for 30 seconds and then becomes very quiet. Mazda says you can put in gear right away without hurting the car and the noise will go away right away. As others have said, the idea is to warm up the engine as fast as possible and thus wasting less fuel on cold-starts. It's a good thing
I've read the purpose of this cycle in first 30 seconds is to get the converter temperature up as soon as possible for lower emissions. Direct injected cars are normally slow to warm up. My direct injected Lexus sometimes takes 3 miles of moderate driving to warm up.
The actual reason for the louder noise is the engines ignition is adjusted to allow the catalytic converter to warm up quicker for reduced emissions and better fuel economy. It is by design and all the SKYACTIV-G engines do it. The 2012 Mazda3's do it as well. It lasts 30 seconds at most.
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- Mazdaspeed6
This isn't utilized in just Skyactiv engines. It is a method used in most newer makes and models.
The engine idle speed is raised to more rapidly warm the engine and catalytic converter. The grumbly sound heard in the exhaust note is from heavily retarded spark advance, which allows heated exhaust to be released into the catalyst before it is absorbed by the cylinder.
Retarded timing results in higher exhaust temps. Advanced timing will heat the cylinder more, as it will absorb heat from exhaust gasses which are retained longer. The upped idle speed is simply hurrying the process.
Also, DI engines are noisier than PI engine, as there is an additional fuel pump driven by a cam which is necessary to inject the fuel at the super high pressures, apart of the DI engine design. The injectors themselves are noisey as well, and have a clackity sound similar to a diesel engine.
The engine idle speed is raised to more rapidly warm the engine and catalytic converter. The grumbly sound heard in the exhaust note is from heavily retarded spark advance, which allows heated exhaust to be released into the catalyst before it is absorbed by the cylinder.
Retarded timing results in higher exhaust temps. Advanced timing will heat the cylinder more, as it will absorb heat from exhaust gasses which are retained longer. The upped idle speed is simply hurrying the process.
Also, DI engines are noisier than PI engine, as there is an additional fuel pump driven by a cam which is necessary to inject the fuel at the super high pressures, apart of the DI engine design. The injectors themselves are noisey as well, and have a clackity sound similar to a diesel engine.
