M56 Blown Rod Bearing 47k Miles

[adeedpb]

About a month ago I began hearing some ticking from the engine bay. It sounded like top end noise and as I was almost due for an oil change I went ahead and did a fresh change. Oil level was a little low but not below safe area on dipstick. Drove the car for another 1000 miles after the oil change and I began hearing a more pronounced bottom end knock.

I called Infiniti the next morning on my way to work because it was definitely starting to get louder. Infiniti told me to bring the car in and on my way to the dealer the knocking got louder soon followed by the sound of shearing metal flinging around in the crankcase and every light on the dashboard lighting up. Engine completely died and I coasted to a stop on the shoulder of the highway. The starter wouldn't even crank the engine over.

Well after a month I have a brand new engine, I was given a loaner no charge for the entire time, and didn't have to pay out a cent. Elite warranty FTW!

So the dealer diagnosis was the #1 Rod Bearing sheared apart causing connecting rod and #1 piston tear up the cylinder. This happened at 47k miles on an engine maintained perfectly, by the same Infiniti dealer with oil changes performed more frequently then recommended. Infiniti said it is not known to be a common issue.

Anyway, Elite warranty saved me $12k! Loving my brand new engine, definitely has more power than the old one.

[Ilya]

Nice! Lol. Did you take UpRev off before they got the car? Lol

[EdBwoy]

Wow! I feel like the ghosts of M45s past are here to haunt us, lol.

I am glad you got a brand new engine with no hassle. It's usually about $17k, labor included.

3 questions I'm curious about if you don't mind:

1. Are you the original owner of the car?
2. Any idea what grade of oil the service dept was using?
3. Had you had the timing chain recall done on your engine?

[Kprad12]

if your car was at 47k miles the elite warranty wouldn't matter because all cars come with the 60k mile powertrain warranty but I am glad you got it fixed before then. I don't know what i'm missing here but why exactly do you have the elite warranty?

[adeedpb]

Wow! I feel like the ghosts of M45s past are here to haunt us, lol.

I am glad you got a brand new engine with no hassle. It's usually about $17k, labor included.

3 questions I'm curious about if you don't mind:

1. Are you the original owner of the car?
2. Any idea what grade of oil the service dept was using?
3. Had you had the timing chain recall done on your engine?

1. I am not the original owner, I believe the vehicle was a lease turn in.
2. Dealership was using 5w30 Pennzoil I believe. In my final oil change I performed myself before the bearing went out I used Mobil 1 10w30.
3. Timing chain recall had been performed prior to this problem, maybe 5k miles before this issue.

[Ilya]

if your car was at 47k miles the elite warranty wouldn't matter because all cars come with the 60k mile powertrain warranty but I am glad you got it fixed before then. I don't know what i'm missing here but why exactly do you have the elite warranty?

He probably has elite because that warranty you mention has a time (or mileage) limit.

[Mjkkb2]

5 yr 60 k miles whatever comes first.

[EdBwoy]

OK, thanks for your response adeedpb.

Way back when, I was concerned as to what exactly qualified people for a new engine during the recall:
link to post, but I suppose it's just bad/ good luck of the draw on your part.

I'd say the failure rates for these engines are pretty low; and hey, percentages exist for a reason. Your engine might have been the 0.001% defect

[armybrat]

1. I am not the original owner, I believe the vehicle was a lease turn in.
2. Dealership was using 5w30 Pennzoil I believe. In my final oil change I performed myself before the bearing went out I used Mobil 1 10w30.
3. Timing chain recall had been performed prior to this problem, maybe 5k miles before this issue.

Wow I also bought my '12 M56x off of a lease in Sept '15. Mine had 52k miles at the time. I have 85k now with no issues so far. Like yours, my car was maintained at the dealership, this one in NY. They used the bulk 5W30 Nissan oil (whatever that is) when they performed oil changes. Not sure if it's mineral based or synthetic. Since I've had the car I've always used Mobil 1 5W30, except for two oil changes where I tried the Mobil 1 0W40. With that said, these cars do use oil, so there's really no way to know if the original owner (yours and mine) thought to check the dipstick between the oil changes. It's possible that they didn't, and some damage could've occurred beforehand.

[Ilya]

I almost never check my oil level. I just change it every 5kmi. I should probably get in the habit of doing this.

[EdBwoy]

True. Some owners forget to change the oil, some dealerships screw up oil changes, some cars have inherent oil issues.
All you can do, especially as a non-original owner is keep up the maintenance and cross your fingers.

From the book titled "100 ways to kill an Infiniti M45",

+ Used synthetic oil with good intentions but ignored to check the oil for too long a time [Remember, just because the new recommended OCI is 10,000 miles, your engine still probably consumes oil at its regular intervals]

[armybrat]

OK, thanks for your response adeedpb.

Way back when, I was concerned as to what exactly qualified people for a new engine during the recall:
link to post, but I suppose it's just bad/ good luck of the draw on your part.

I'd say the failure rates for these engines are pretty low; and hey, percentages exist for a reason. Your engine might have been the 0.001% defect

Under the timing chain recall, you qualified for a new engine if your oil jet hole didn't spec out. They inserted a go-no go gauge into the hole to check it.

[armybrat]

I almost never check my oil level. I just change it every 5kmi. I should probably get in the habit of doing this.

I agree, you should. I went 5K before I checked it the first time. The dipstick was bone dry.

[EdBwoy]

...
Under the timing chain recall, you qualified for a new engine if your oil jet hole didn't spec out. They inserted a go-no go gauge into the hole to check it.

I understand that. My concern was that the tolerances allowed by the go/no go gauge might be "looser" than those of a factory assembled engine.
... but it's alright. If most of those engines/ years that underwent the recall are still on the road, then it's all good. If more of them start having rod knock, then we can revisit the issue and start asking why.