2012 M35h Cold Start Strange Engine Noise

[BWheetley]

This may be normal for the 3.5 Atkinson cycle engine that Infiniti uses in their M Hybrid, but I wanted to see if others have had concern. On a cold start each morning, the engine makes some strange sounds. I'm not sure if it is lifter noise, knocking, or what else. I made a video of 3 different start ups so you could hear it. In the video I note where the sound begins. Any feedback would be great.

http://www.youtube.com/watch?v=XeDHRt0EmEQ

[svard75]

Does the noise go away eventually? Sounds like lifters. Your engine has Variable Valve Timing for the intake valves and as you mentioned the engine's cycle keeps them open a bit longer than the typical engine. Perhaps it has something to do with that? Have you heard other M35h engines?

Sorry I couldn't be of more help.

[mazz]

I often found with Infiniti 6 and 8 cylinder when they don't run long enough, like the start after a 30 second run, I get strange noises.
An example would be to back car out of garage to wash next start can be noisy . I have owned 3 m and 4 q . the m were all v6

[atlM35]

Check the oil level.
I get lifter noise in between oil chances until I top it off

[BWheetley]

Thanks for all the responses. The noise does eventually go away after about 60 seconds after the cold start. I will check the oil level in the morning to see what it's at.

[TXT]

Ahhhh yes.

http://www.youtube.com/watch?v=rSfUzWM81Tg

I made that video about a year ago. Similar to yours, if not the same exact noise. (Differences in Microphone?)
Made that sound every morning for a week straight. I didn't do much about it because I was scheduled for an oil change the coming week. When I got the oil change, sound never came back.

Like others have said, check your oil level and top off if needed. If not then go get an oil change if you want and bring up this issue to the dealership (show them your youtube vid). Oil change is a small price to pay to possibly fix this problem and once again give you peace of mind.

[BWheetley]

That's good to know. I will check the oil and see where it's at. Hopefully it's something simple. I will ask the dealer about it the next time I go in just to be sure.