Ok who knows how the electronic engine mounts operate??
09-08-2000, 06:17 PM
#1
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My joy over the new TCM was a little tempered by my engine mounts being "chirpy" even though both have been replaced...
What I mean by chirpy is if I feather the gas(in Park)there is a little chirp that starts of the rev and then as the rev ends...
This really is a puzzlement to both myself and the tech who did the work on the car...I personally worked with the tech when we diagnosed the problem....with his Consultant II he turned of the engine mounts and feathered the gas while I was listening under the hood...no chirp or noise at all...turns mounts back on "chirp" under same feathering...
Both mounts have been replaced but apparantley that isn't the problem....when I do the same test on a co-workers 2K Max I can hear what sounds like a silmilar noise but not as pronounced..sounds more like a vacum woosh(other than the normal engine woosh)than chirp.......
Does anyone have any knowledge of what could be causing this noise? is there a vacum hose connection that could be seeping or leaking to cause this noise? Doesn't seem to be affecting the performance of the car at all but sure is annoying as all hell..
Before I left the dealership this afternoon I walked back in to talk to the SM about the problem.......he asked me to stop in any day next week so the tech that worked on it would be around..(they had all gone home for the day)
Not out of my way so I said sure(as opposed to what else could I say?
)
Oh they fixed the rattles on my radio also but Apillar still buzzes a bit...also anyone else notice that the key lock on the glovebox buzzes? Sounds like a bunch of bees sometimes
What I mean by chirpy is if I feather the gas(in Park)there is a little chirp that starts of the rev and then as the rev ends...
This really is a puzzlement to both myself and the tech who did the work on the car...I personally worked with the tech when we diagnosed the problem....with his Consultant II he turned of the engine mounts and feathered the gas while I was listening under the hood...no chirp or noise at all...turns mounts back on "chirp" under same feathering...
Both mounts have been replaced but apparantley that isn't the problem....when I do the same test on a co-workers 2K Max I can hear what sounds like a silmilar noise but not as pronounced..sounds more like a vacum woosh(other than the normal engine woosh)than chirp.......
Does anyone have any knowledge of what could be causing this noise? is there a vacum hose connection that could be seeping or leaking to cause this noise? Doesn't seem to be affecting the performance of the car at all but sure is annoying as all hell..
Before I left the dealership this afternoon I walked back in to talk to the SM about the problem.......he asked me to stop in any day next week so the tech that worked on it would be around..(they had all gone home for the day)
Not out of my way so I said sure(as opposed to what else could I say?
)Oh they fixed the rattles on my radio also but Apillar still buzzes a bit...also anyone else notice that the key lock on the glovebox buzzes? Sounds like a bunch of bees sometimes
09-08-2000, 06:23 PM
#2
my understanding is that
of the three mounts, only the rear is active, the other two are regular rubber mounts... hmmm... That sounds more like a belt or a pulley to me. see if you have a frayed belt. Yeah, tech shoulda checked that... but..
there are two things attached to the top of the glove box housing. An airbag connector and the glove box light. Both of these have loose wires that just lay on the top of the glove box. that whole thing drops down with 6/7 screws.. but there are also some access holes that you may be able to reach up and put a piece of tape on the wires. That should take care of that noise.
there are two things attached to the top of the glove box housing. An airbag connector and the glove box light. Both of these have loose wires that just lay on the top of the glove box. that whole thing drops down with 6/7 screws.. but there are also some access holes that you may be able to reach up and put a piece of tape on the wires. That should take care of that noise.
09-08-2000, 06:44 PM
#3
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Well that was my first thought Tim..
I would never had suspected the mounts..whn I first brought it in I said I had a squealy belt...after the tech listened for a bit he said it sounded more like a vacum sound...
I'm a little puzzeld as a belt does sound like a logical guess but when he turns off the mount, the chirp stops.
That leads me to believe it is somehow related to the mounts either in the mount itself(new mounts though) or something in the chain that leads to the mounts or something after the mounts that is affected by them being on.
In other words I ain't go not flipping clue
I'm a little puzzeld as a belt does sound like a logical guess but when he turns off the mount, the chirp stops.
That leads me to believe it is somehow related to the mounts either in the mount itself(new mounts though) or something in the chain that leads to the mounts or something after the mounts that is affected by them being on.
In other words I ain't go not flipping clue
09-11-2000, 02:03 PM
#6
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Posts: 609
I stopped off at the dealer today to talk to the
tech who replaced the engine mounts. He is baffled
as I am at what is causing this squeak(chirp or
whatever).
He hooked up his Consultant II and is able to turn
the mounts off and on. When he turns the mount
off and feeds a little gas, there is absolutley no
chirp. Turns the mount back on and it immediatly
chirps. Turns it off...no noise.
He explained a little bit on how a mount works but
he had me at hello Actuator?
Car seems to not make the chirp unless it is
fairly warm...(running for about 5 minutes)
He is placing a call with Nissan tonight to see if
they can help him at all and I'm to get back to
him midweek....
So it sounds like a belt and all that other stuff
is ruled out.....does the mount move the engine
enough to cause something else to squeak?
Oh well just another problem I have with
Nissan...jeesh.
tech who replaced the engine mounts. He is baffled
as I am at what is causing this squeak(chirp or
whatever).
He hooked up his Consultant II and is able to turn
the mounts off and on. When he turns the mount
off and feeds a little gas, there is absolutley no
chirp. Turns the mount back on and it immediatly
chirps. Turns it off...no noise.
He explained a little bit on how a mount works but
he had me at hello Actuator?
Car seems to not make the chirp unless it is
fairly warm...(running for about 5 minutes)
He is placing a call with Nissan tonight to see if
they can help him at all and I'm to get back to
him midweek....
So it sounds like a belt and all that other stuff
is ruled out.....does the mount move the engine
enough to cause something else to squeak?
Oh well just another problem I have with
Nissan...jeesh.
09-12-2000, 07:00 AM
#7
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Posts: n/a
Electronic Controlled Engine Mounts
There are four mounts on your engine. The upper right and left mounts are the standard inactive solid rubber type. The front and rear mounts are the fluid filled active controlled type. The front and rear mounts are the two attached to the center member at the bottom of the engine compartment.
Here's my educated guess at how the mounts work. The mounts have an electronic actuator that locks the mount in place when the car is moving. When the car is idling, the engine is allowed to float on the fluid filled rubber mounts which does a good job of dampening engine vibration. When the engine revs rise above idle, the actuator locks the mount so that it acts more like a solid mount. This keeps the engine from flopping around as the car starts moving.
According to the FSM, the ECM looks at engine speed and vehicle speed to determine if the mounts should be in "soft" or "hard" mode.
In your case, as you rev the engine the mounts are stiffened and the engine vibration is causing something to rub together and cause the chirping sound. Perhaps the tech should get under the car to determine if the noise is coming from the mounts or from somewhere else.
Here's my educated guess at how the mounts work. The mounts have an electronic actuator that locks the mount in place when the car is moving. When the car is idling, the engine is allowed to float on the fluid filled rubber mounts which does a good job of dampening engine vibration. When the engine revs rise above idle, the actuator locks the mount so that it acts more like a solid mount. This keeps the engine from flopping around as the car starts moving.
According to the FSM, the ECM looks at engine speed and vehicle speed to determine if the mounts should be in "soft" or "hard" mode.
In your case, as you rev the engine the mounts are stiffened and the engine vibration is causing something to rub together and cause the chirping sound. Perhaps the tech should get under the car to determine if the noise is coming from the mounts or from somewhere else.
09-12-2000, 02:01 PM
#9
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Join Date: Aug 2000
Posts: 609
Thanks STLV...
that is exactly what I think it is...I think it is not the mounts themselves(both have been replaced) but rather another piece of the engine that is reacting to the activation and deactivation of the mounts. However when I mention my thoughts to the tech he quickly dismisses them.....pretty hard to work with(and stay nice to) a guy who seems to know everything except what the ^%$# the problem is.
I'm going to start another post about steering wheel vibrations...don't know if it has anything to do with the mounts......
I'm going to start another post about steering wheel vibrations...don't know if it has anything to do with the mounts......
09-12-2000, 03:06 PM
#10
Re: Electronic Controlled Engine Mounts
Originally posted by STLV
There are four mounts on your engine. The upper right and left mounts are the standard inactive solid rubber type. The front and rear mounts are the fluid filled active controlled type. The front and rear mounts are the two attached to the center member at the bottom of the engine compartment.
Here's my educated guess at how the mounts work. The mounts have an electronic actuator that locks the mount in place when the car is moving. When the car is idling, the engine is allowed to float on the fluid filled rubber mounts which does a good job of dampening engine vibration. When the engine revs rise above idle, the actuator locks the mount so that it acts more like a solid mount. This keeps the engine from flopping around as the car starts moving.
According to the FSM, the ECM looks at engine speed and vehicle speed to determine if the mounts should be in "soft" or "hard" mode.
In your case, as you rev the engine the mounts are stiffened and the engine vibration is causing something to rub together and cause the chirping sound. Perhaps the tech should get under the car to determine if the noise is coming from the mounts or from somewhere else.
There are four mounts on your engine. The upper right and left mounts are the standard inactive solid rubber type. The front and rear mounts are the fluid filled active controlled type. The front and rear mounts are the two attached to the center member at the bottom of the engine compartment.
Here's my educated guess at how the mounts work. The mounts have an electronic actuator that locks the mount in place when the car is moving. When the car is idling, the engine is allowed to float on the fluid filled rubber mounts which does a good job of dampening engine vibration. When the engine revs rise above idle, the actuator locks the mount so that it acts more like a solid mount. This keeps the engine from flopping around as the car starts moving.
According to the FSM, the ECM looks at engine speed and vehicle speed to determine if the mounts should be in "soft" or "hard" mode.
In your case, as you rev the engine the mounts are stiffened and the engine vibration is causing something to rub together and cause the chirping sound. Perhaps the tech should get under the car to determine if the noise is coming from the mounts or from somewhere else.
I have a 5-speed and do you think I have electronically controlled mounts too.
09-12-2000, 03:16 PM
#11
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From what I have heard only the Autos have them. I think the 5sp doesn't really need them because when they idle there is no load on the engine. The Auto still need to turn the torque converter during idle and the electonic mounts will help reduce the vibration when it is.
09-13-2000, 11:56 AM
#12
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Join Date: Aug 2000
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Well I called the dealer today
and the tech said he had been in contact with Nissan. Their recommandation? Replace the computer..wtf? Does this make any sense? How would the computer affect how my engine mounts sound?
Who knows, maybe I am naive and they are related....lets see..car is 2 months old...2 engines mounts, computer, vibes, rattles, slippery tranny hmmm what is next?
Who knows, maybe I am naive and they are related....lets see..car is 2 months old...2 engines mounts, computer, vibes, rattles, slippery tranny hmmm what is next?
09-14-2000, 05:58 AM
#13
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ECU Swap
First of all I assume the chirp you are getting is happening only when the car is in Park. According to the FSM the ECU only looks at engine speed and vehicle speed to determine how the mounts should be adjusted.
Perhaps the logic in the lastest ECU version have some slight changes in the way the mounts are controlled. The ECU may not lock the mount in the firmer mode unless the car is in Drive.
Ask the tech how this ECU change will effect the operation of the mounts. For Nissan to recommend an ECU change, there must be something different in the way the electronically controlled mounts operate.
Perhaps the logic in the lastest ECU version have some slight changes in the way the mounts are controlled. The ECU may not lock the mount in the firmer mode unless the car is in Drive.
Ask the tech how this ECU change will effect the operation of the mounts. For Nissan to recommend an ECU change, there must be something different in the way the electronically controlled mounts operate.
09-14-2000, 06:19 AM
#14
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Actually
the chirp will appear either in park or drive or reverse(basically any gear) It is only noticable when in Park when I do the feather test or if lets say I am backing out of my drive way or creeping very slowly along.
Call me a pessimest but I don't see how the computer will solve this problem...I would think that if it was a computer issue, there would be quite a few other cars with the same problem.
Then again being naive about how the computer actually works who knows
Call me a pessimest but I don't see how the computer will solve this problem...I would think that if it was a computer issue, there would be quite a few other cars with the same problem.
Then again being naive about how the computer actually works who knows
09-15-2000, 05:42 PM
#15
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It sounds like the noise can be produced while the car is in park or neutral with the engine is running. If your willing get your hands a little dirty you may be able to identify the offending part.
You'll need a lenght of heater hose, about 3-4 ft. Use it like a stethescope to probe around and locate the noise. You can actually place it on the offending part.
Take care to keep your arms, hands, clothing, and the hose clear of all moving parts such as belt and the fan. You should also place the car in park and/or block/chock the wheels and set the parking brake.
It's a pretty low tech way of locating the noise and sometimes more effective than hooking the car up to the diagnostic computer. My dad, a heavy equipment maintenace machinist showed me this. It's worked for me numerous times.
You'll need a lenght of heater hose, about 3-4 ft. Use it like a stethescope to probe around and locate the noise. You can actually place it on the offending part.
Take care to keep your arms, hands, clothing, and the hose clear of all moving parts such as belt and the fan. You should also place the car in park and/or block/chock the wheels and set the parking brake.
It's a pretty low tech way of locating the noise and sometimes more effective than hooking the car up to the diagnostic computer. My dad, a heavy equipment maintenace machinist showed me this. It's worked for me numerous times.
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