Buzz noise after engine is turned off...
 

I did a quick search and couldn't find anything... but I have a noise after I shut my car off that lasts for about 5 seconds. I had my dad check it out (technician at the dealership...) and he found a service bulletin that only applies to auto trannies in maximas built before October 2, 2000 and it is titled "Buzz noise after engine is turned off". I saw a link called "buzz noise" in the service bulletin sticky, but it's dead. I have the bulletin printed out, I'd be glad to provide it when I get home if you want to see it.

My questions are, why in the h*ll do we have electronically controlled motor mounts? Never heard of that before.

What are the negative things that will happen if I don't replace the motor mounts? I can't tell any difference with them being bad... it just makes that dang noise when I shut the car off.

My dad doesn't think that I NEED to replace them... but I don't want anything to happen. My cost will be about $300 in parts. Thanks for your opinion.
(If this has been discussed many times before, you have every right to flame me to no end...:repost2: )

Maybe your noise is different than mine but if you think there is something wrong with your engine mount, go have that checked asap.
See my story here: http://forums.maxima.org/showthread....487272&page=68 (post #2037)
Read some pages after, you'll see some other stories about burned engine mounts.

In my case the engine mount fried the ECU and I had to pay 1900$ to fix it.

Found NTB01-010:
http://www.nissantechinfo.com/nissan...RefNo=NTB01010

http://i7.tinypic.com/6bad6k2.gif
http://i13.tinypic.com/4u40fah.gif
http://i12.tinypic.com/4mrjfbt.gif

In my case the engine mount fried the ECU.
If there is a TSB about this, should the dealership fix the issue for free?

Nope... TSB doesn't mean recall. My dad said that when that bulletin came out, they probably offered replacement mounts at a reduced rate... but i'm stuck spending about 300 bucks for the two parts (as opposed to 400 for regular customers).. so it's that serious of a problem that it fried the ECU!?!?!?

I was just going to live with the noise... but maybe I won't be able to do that like I had hoped.

The guy at the dealership said this was an issue with Maxima 2k and 2k1; engine mounts burning the ECU. The issue was fixed after 2k1 model.
Also the ECU I have now has a different P/N than the one I had before.

Same problem I had about a year or 2 ago! I would shut the car off and there would be a buzzing noise for about 3 seconds. I used to notice all the time when I shut the car off. Then all of a sudden one day last year it totally stopped making the noise! The engine and ecu has been fine ever since so I figured maybe it just fixed itself unless it is just totally dead! Since I haven't heard the noise I figured I would be unable to take it to the stealership as they would probably say nothing is wrong since they do not hear any buzzing noise! I do have an extended warranty til 100k or Oct '08 and currently the car has 90k, so if the noise comes back maybe I should take it to the stealership!

Good luck with your scenario jdmaxima89!

Had the same problem... front mount would make noise for 3-6 seconds and it would stop... one day it started making noise and it would never stop ;-) so i unplugged the harness.. Called my friendly Nissan tech, he told me its $300+ to get it replaced (ouch) , and he said that if i don't want to replace it i can drive with it unplugged. it was over a year ago.. ;-) its still unplugged..

Hmmm... I may consider unplugging it then. Thats the cheapest way lol.

Yup... I don't see any side effects of doing that.. so it is the cheapest fix possible ;-)

you didn't even get a check engine light?

nope. confirmed by nissan tech that this will not cause CEL.
over a year now... everything is good.

Cool... that's probably what I'm going to end up doing then. My dad said that the main purpose of the electronically controlled engine mount is that it pretty much holds the motor "tighter" while you are idling. That's why we hear it when we are either slowing down to a stop, or shut the car off.. or in my case, both.

With the harness unplugged, would it leave the engine mount bushings in the 'soft/loose' state?

I looked over the FSM diagrams (2001 FSM Pages EC-625 to EC-628) and interpreted it as (could be wrong):
Below 2000 RPM, engine mounts: Soft
Above 2000 RPM, engine mounts: Hard

I was going to unplug mine too, but thought it may leave the mounts in a permanent soft state. I haven't heard the noises, but would like to keep them unplugged to keep the ECU safe.

I have the exact same issue, what is the long term ramifications for leaving the harness unplugged if any?

KSS

How do you unplug them, where is the connector for them?

And do the 5 speeds have electronic mounts?

Who cares about the buzzing sound, it doesn't bother me...Plus I don't need a bracket in my engine if I got on it hard

The buzzing sound indicates there is a bigger issue, its not the sound itself I believe. No one wants their car to catch on fire

How would it cause a fire?

How would it cause a fire?

EDIT: If it continued to keep buzzing got it...:)

5spds don't have electronic motor mounts.

I have a buzzing sound after i turn the car off, and a squeal at around 2k rpm (where it apparently stiffens) when accelerating. I cant figure out the cause of either...but apparently they are unrelated.
I have just replaced both lower mounts with ES inserts with no change in these sounds (ES bushings are awesome otherwise)
Therefore the sound you guys are hearing could possibly be from something else.

thanks :)

I had my front one replaced. Mine started making a whining noise once you reved the motor. I unplugged it til I got a new one. I get the buzz noise still but my rear is still fine.

Actually I have a 2k2 SE 6MT and I have a buzzing(or distance horn) after I shut my engine off but I figured it was a capacitor or something. If this is an A/T problem only has anyone else with a M/T heard a similar sounds.

I thought i have heard the noise too. How loud is it?
kind of like when the buzzer for an older dryer goes off?

mine has like a buzz buzz tick tick buzz and lasts about 3-5 seconds.. shes been doing it forever like a year + and have had no problems.. so idk

same here most specially whens its cold. it happens everytime i shut off the car or rev it.

Video Of the sound

http://smg.photobucket.com/albums/v7...t=S5000039.flv

http://smg.photobucket.com/albums/v7...t=S5000040.flv

Does anyone know how to unplug the harness to the motor mounts so it doesn't make this noise?

thx

kss

i always thought it was the electronic motor mounts like correcting something..

the aircon does make a noise when you turn it off or turn your car off with it on.

That is your motor mount. I would unlug it now. I really didn't feel a difference when I unpluged mine. The front one is little maroon plug almost by the o2 sensors. I don't a pic and I don't know where the rear one is.

Front Motor mount
 

I am having this problem now with a after market one. I had the starter replaced this weekend and disconnected the battery and once I reconnected the battery the buzzing noise does not stop at all. I blew a fuse after driving for 20 miles and the car died. Any ideas?

I would like to say this forum is amazing..I have had two problems and did nothing but type in a search phrase and found my answers. You all are a real help to a guy that knows very little about motors.

Thanks so much!

Matt
Merriam, KS

I had to change out my starter motor and happen to see the elec. connector for the rear motor mount, so I unplugged it.

I don't think I would have been able to access it without removing the airbox. so if you are trying to disconnect your rear elec. mount connector, take out your airbox and you'll see the connector. It's looks like the front one and has a long wire that runs to the vicinity of the rear mount.

I have them both unplugged just to be safe so that I don't blow out the ECU. At some point I'll probably replace them with ES mounts.

I read somewhere if you disconnect the electronic motor mount harnesses you have to go through a re-learn process for air idle etc something or another? Any of you guys who disconnected your harnesses have to do anything once you disconnected harnesses like I mentioned?

You must have read that from George. :laugh:

I'm not sure where I read it actually nor am I sold it's my Elec Motor Mounts as I turned off my climate control/heater today before shutting off car once today and it didn't occur, but another time thought it did (it was really windy out so wasn't sure). Will have a 2nd person shut it off while I'm under hood tomorrow.

When you go to unplug the motor mounts permanently, have the engine rpm up over 1K. This will set the motor mount in firm mode.

Thank you...I'll let everyone know how it goes.

Well it's the dual radiator fans clunking a bit after car is shut off NOT electric motor mounts. Never changed them out so I'm sure it's time after $215k miles to say the least.