Nissan 370Z Forum - My ECM replacement (high pitched whine) was denied

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Quote:

Originally Posted by Sh0velMan (Post 2803944)

lol.

TB whine is totally normal, I hope you guys aren't bothering a service dept over that.

No, not me. The less a person fidgets with my car the best it is. Me including LOL:roflpuke2:

Quote:

Originally Posted by fitxpert (Post 2803534)

I had my ECM replaced and still experienced the whine. Did a little further reading and did a little testing and realized it's the THROTTLE BODIES. Here is how you can tell if the noise is coming from your throttle bodies or ECM.

Pop your hood.
Put the car in Neutral.
Set ignition to ON.
Roll your windows down.

At this point...it should be silent.
Now put the car into gear. I usually go with 2nd. You should hear the whine start right away.
Now put your ear near each throttle body and confirm. I could hear each throttle body whining.

I had my service manager convinced it was the ECM...and it turns out that wasn't the problem. Here is a video of the noise well. Car is in gear.

Throttle Body Whine

Sorry but I've never heard a silent internal combustion engine :icon14:

Sure I've heard the noise, and I don't have to put my ear next to the throttle bodies. Is it indicative of anything wrong? Absolutely not.

Enjoy the hassle of the dealer trying to get them to troubleshoot something that is completely normal. On the plus side, they might break something unrelated, so you need their service for real :eekdance:

The TBs are never silent.

They are quiet(er) when they are new, but as they age and break in the noise becomes more prevalent. This is due to how they work, they're little DC motors that are having to hold the TB open against a spring. This creates vibrations that become more audible as the bearings wear in.

There's seriously nothing to fix until the TBs begin to malfunction from bearing play or (more likely to be an issue first) the brushes wear out/get too dirty to function and the TB has to be serviced (replaced by the dealer, no one fixes them, they just R&R and send it off to be "recycled", but I have personally refurbed DBW TBs in my garage without issue).

Again, it's a non issue and you can only hear it on this car more than others because the TBs are front and center, not covered up by feet of equipment to muffle the sound (and there's two of them).

OH, and because this is one of the few cars without an under-hood heat and sound insulating pad.

If it had a half inch thick pad to absorb engine bay sounds you wouldn't hear the TBs at all.

Nissan (incorrectly, apparently) assumed sports car owners wouldn't care that they could hear TB whine, relay chatter and other mechanical noises from their engine bays and decided to save that space that would be needed so they could make the hood lower profile, thus improving aerodynamics and aesthetics.

Quote:

Originally Posted by Sh0velMan (Post 2804003)

Dynomat makes an underhood liner product for people who don't want to hear these kinds of noise.

Quote:

Originally Posted by Chuck33079 (Post 2804011)

Dynomat makes an underhood liner product for people who don't want to hear these kinds of noise.

Perfect.

FWIW, the G37 has a pad, it also has a bulkier hood and no strut tower brace.

The VQ37 is a tall motor, they had to min-max the entire design to meet design goals, random noises are a small compromise.

this is the first time I've heard of people complaining about throttle body whine in a modern car

Amazon.com: Thermo-Tec 14620 60" X 36" Heat and Sound Suppressor: Automotive

That would be my first choice. The Dynamat one is thicher, so you may have to do more trimming and shaving the foam down.

Dynamat.com | The Hoodliner for Automotive and Restoration