Intermittent misfire type symptoms '15 Mirage bought one month ago 31k miles

Dealer refuses to look at the until problem goes from intermittent to constant.

2015 Mitsubishi Engine Noise 1.2L
Happens for 30 seconds during cold start. Then sometimes comes back 1 minute later for another 30 seconds.
Car has only 31k miles on it.
Dealer refuses to look at it until noise becomes constant instead of intermittent.
Any clues?
Did not start happening until yesterday.
Car had 30k mile service @ 29.3k miles a few months ago and checked fine at the time.

Thank you

https://youtu.be/-a54iTpRL5o

Quote:

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Originally Posted by DFWMirage

Dealer refuses to look at the until problem goes from intermittent to constant.

2015 Mitsubishi Engine Noise 1.2L
Happens for 30 seconds during cold start. Then sometimes comes back 1 minute later for another 30 seconds.
Car has only 31k miles on it.
Dealer refuses to look at it until noise becomes constant instead of intermittent.
Any clues?
Did not start happening until yesterday.
Car had 30k mile service @ 29.3k miles a few months ago and checked fine at the time.

Thank you

https://youtu.be/-a54iTpRL5o

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Have you checked your oil level to make sure they didn't overfill? I'd try a different dealer if your oil level is ok, that's a lot of valvetrain noise.

Hello DFWMirage and welcome to the forum.

Sorry to hear you are having these problems with your Mirage! While I can't say I'm familiar with these symptoms, I too would like to know what could be causing this.

It might be helpful to know more details about you and your Mirage - consider making a garage entry here on the forum:
Garage empty: add car
Take a look at my garage entry for an example and browse others here too. This can help us better understand what's going on.

I have some questions for you:

1. Air Conditioning
   Your Mirage was sold with an automatic climate control package that has the air conditioning compressor running pretty much all the time. This auto AC operation can be changed, and the instructions can be found in the owner's manual.
   
   1. Is your air conditioning running?
   2. Have you turned off auto AC?
   
   If you need help with this, refer to this forum post. Turning off auto AC is real simple.
   
   
2. Engine oil
   The Mitsubishi Mirage 3A92 motor uses MIVEC variable valve timing and is operated by hydraulic pressure from the motor oil. Clogged oil passages could interfere with this.
   
   1. When was your last oil change?
   2. Do you change it yourself?
   3. How often has the oil been changed?
   4. What type of oil is used - info such as who sells it, conventional or synthetic, viscosity?
   5. What filter is being used?
   
   
3. Fuel
   Low quality fuel can cause a host of problems for any engine.
   
   1. What brand do you use?
   2. Refer to the Top Tier Gas webpage for more info.
4. Air filter
   It's not likely that a dirty air filter could cause your symptoms, unless it is somehow contributing to rich fuel conditions...
   
   1. When has the air filter been last inspected?
   2. If necessary, has it been changed?

I watched your YouTube video and I have to confess I didn't notice any unusual noises. Initially I thought to check and document the simple engine maintenance items such as fuel, oil, filters then I remembered the auto AC. I'm going to guess that you recently got your Mirage and are new to how it runs.

If you are a new Mirage owner, congratulations and welcome to our little club. These are great cars and have proven to be quite reliable.

That being said, the one recurring problem that has been more or less discovered among owner members here on the forum has been rear axle alignment. Get yours checked. If caught in time, Mitsubishi will take care of it under warranty.


Looking forward to hearing back from you soon.

This is a new one. It almost sounds like timing chain noise or something? Definitely check oil level and condition.

I'd tell the *******s at the dealership it IS a constant noise and make them look at it.

What the others said! Tell the dealership to look at it again.

From your sound clip i cant tell anything but i would suggest pulling the accessory belt and starting the engine. It's possible the alternator is screwed up or something got inside chewing up the windings.

Also worth looking into the oil fill cap, who knows maybe there will be a cam lobe sitting there lol

Quote:

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Originally Posted by DFWMirage

Dealer refuses to look at the until problem goes from intermittent to constant.

2015 Mitsubishi Engine Noise 1.2L
Happens for 30 seconds during cold start. Then sometimes comes back 1 minute later for another 30 seconds.
Car has only 31k miles on it.
Dealer refuses to look at it until noise becomes constant instead of intermittent.
Any clues?
Did not start happening until yesterday.
Car had 30k mile service @ 29.3k miles a few months ago and checked fine at the time.

Thank you

https://youtu.be/-a54iTpRL5o

---

Take it to another dealer and file a complain with mitsubishi, your car is still under warranty...

Thanks everyone for the responses so far!

For those that can't hear it. Listen for the sound pitching up and down, as if something is running uneven.

Turning AC on and off doesn't affect it.
Oil was changed at a shop right before I bought the car 3 months & 2k miles ago. Oil level is within normal range.
Gas is only purchased from Chevron, Shell, Exxon, etc
Air filter was changed 3 months & 2k miles ago.

So far a timing chain running uneven in there has been one of my theories as well.

Quite a pickle. Haven't found anyone else with this issue

Hook up a scan tool or code reader and see if any OBDII codes have been set. If what you are perceiving is really a misfire, you might see 1 or more codes set like P0300 (random misfire), P0301, P0302, etc. A really bad misfire would cause your check engine light to flash constantly.

Being a 3 cylinder, these engines tend to have a bit of idle vibration that some people aren't used to.

Ok, new update. It only happens when I put it in park after a cold start. I start the car, put it in drive, get up to my mailbox, put it in park, and that's when it happens.

Quote:

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Originally Posted by DFWMirage

For those that can't hear it. Listen for the sound pitching up and down, as if something is running uneven.

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Yeah, this is what made me think of the AC compressor. If this were the case, you could see the compressor running each time the engine demonstrates a rough idle. Running the AC causes rougher sounding operation when I'm at idle.