Joined this forum because of valvetrain noise on a cold start. Happy to see I'm not the only one, but it still is of concern to me even though it seems to be "normal" for most G37 engines.

My concern is that the heads are not getting proper lubrication at start-up, which means trouble down the road--probably soon after the warranty expires. If this is a common problem with 3.7 engines, I don't expect that Infinity will admit to it...that would cost them a bundle.

If anyone has a TSB on this problem, I would like to see it. Thanks in advance.

 

My 09 does this too but I don't think it's causing harm. What oil are you using? Many say the Nissan Ester oil can fix this issue, but it's expensive.

 

It's normal... it's because of the VVEL "knocking" sound in the G37 VQ 3.7 engine. The engine just needs some warm lube before the knocking sound is gone.

If it really bothers you, you can opt for the super expensive Nissan ester oil which causes some of the oil to stick to the engine and eliminate the knocking, rough sound during a cold start up. Well, at least it's suppose too.

 

I'm not sure if this is applicable to the G37, but in most modern cars, on cold starts - the engine misfires to help heat the car up. Noisy on start up is normal. Maybe it has something to do with the VVEL system? Valves?

 

Uh...I love the noise it makes following a cold start.

 

I put in the Ester oil and it is still noisy on a cold startup. Maybe a little less so. Supposed to have a 30 sec. warmup and by that time rpm down to 1000 and I don't drive the car hard until engine temp. is up which seems to happen rapidly with the Infiniti. I don't think noise is caused by anything that will do damage as long as you let car warmup before driving aggressively.
J

 

Appreciate the replies after my post. Have to get my wife to let the engine run for a half-minute before driving away.

Don't want to go the ester oil route. I just hope engine longevity is not compromised.

devil2k, you need a solid-lifter 427. I love that sound too, but only when it's supposed to be there.

 

I have had many cars. The G is the first one that I would describe as sounding like $hit, when it is initially started up.

 

Mine does the same thing. Now on the other hand, my freind's Bmw 550I is louder at cold startup. I thought something was wrong with his car, until I went to test drive few preowned 550I's, they all did the same thing. I ended up going with the G, so when I heard my G making similar noise during cold startup, I just assumed that its normal on all the newer cars.

 

Sup guys! Just bought my 2013 Infiniti G37S Sedan, last week. I noticed that rough cold start today as well. Glad to see that this sound is "normal". I may look into this Esther Oil thing from Nissan/Infiniti.

 

this issue has been brought up many times, i think it is totally normal since the engine is still cold and you can see the rev up when the car is still heating up on the p.

 

Had a 2010 G37xS. had warm up noise so i used Ester oil. Perhaps diminished slightly. I just leased same car 2013 version and still ave same noise for 30 seconds particularly when car hasn't been started for a couple of days. Will not use Ester oil this time. 2 year lease.

 

Like others, I was concerned with the lumpy idle, but 2 things put me at ease: 1) the sound always smooths out at exactly the same time, and 2) if you put the car in gear right away, the noise immediately disappears and the car sounds normal. Whatever it is, the computer is controlling it. If it was an oil related issue, I would think the noise would increase when put in D or R.

 

This is normal. I've had five different service loaners and they all do this. For the first ~40 seconds it chugs away like an old motorboat. IMO something very specific and intentional is going on with the firing order, or timing, or valve lift, or a combination of some, all, none or other things. It has nothing to do with oil or engine temp. Probably done for emissions and/or warming up.

 

Yes to ticking and yes to diesel sound. I think the diesel sound is the engine running rich for 30 seconds. I noticed though in the heat of summer it doesn't make the diesel sound for very long.