hard knocking noise when going WOT
10-28-2009, 03:52 PM
#1
hard knocking noise when going WOT
ok so this is weird... i dont know if its a motor mount or what.. but all i know is when i'm going WOT, it feets like there is a hard inconsistant knocking... its strong enough that i feel it in my feet on the floor board...
it happens a couple times and so today i went home... I parked the car, popped the hood... didnt see anything outta whack... pull the ebrake on, put it in reverse, motor rocks just a tad.. then kinda quickly jab the throttle and it rocks but i dont know how much is too much... put it in drive.. and same thing.. rocks pretty good but i dont know how much makes it considered a bad mount..
Arent there poly inserts? vs trying to press out the rubber?
any clue?
it happens a couple times and so today i went home... I parked the car, popped the hood... didnt see anything outta whack... pull the ebrake on, put it in reverse, motor rocks just a tad.. then kinda quickly jab the throttle and it rocks but i dont know how much is too much... put it in drive.. and same thing.. rocks pretty good but i dont know how much makes it considered a bad mount..
Arent there poly inserts? vs trying to press out the rubber?
any clue?
10-28-2009, 04:13 PM
#3
the car is smooth, the gears are smooth, its not like when i'm going WOT that the car shakes or studders all the way to red line no... its smooth but its banging as it goes when i'm wot..
if it is the motor mounts, what makes it do that? the engine rocking back and forth? but if its under staight WOT wouldnt it be pushing and pushing?
So what did you do Rochester? just replaced the front and rear motor mounts? is there inserts? or do i just buy good used low mileage motor mounts from the junk yard or something?
i thought i read somewhere you take off the motor mounts, depress the rubber and the metal ring.. and press in the ES motor mounts...
i wish there were just inserts..
10-28-2009, 04:34 PM
#4
ok do what? the motor mounts you mean? yea its like when i go wot.. its just banging away!
the car is smooth, the gears are smooth, its not like when i'm going WOT that the car shakes or studders all the way to red line no... its smooth but its banging as it goes when i'm wot..
if it is the motor mounts, what makes it do that? the engine rocking back and forth? but if its under staight WOT wouldnt it be pushing and pushing?
So what did you do Rochester? just replaced the front and rear motor mounts? is there inserts? or do i just buy good used low mileage motor mounts from the junk yard or something?
i thought i read somewhere you take off the motor mounts, depress the rubber and the metal ring.. and press in the ES motor mounts...
i wish there were just inserts..
the car is smooth, the gears are smooth, its not like when i'm going WOT that the car shakes or studders all the way to red line no... its smooth but its banging as it goes when i'm wot..
if it is the motor mounts, what makes it do that? the engine rocking back and forth? but if its under staight WOT wouldnt it be pushing and pushing?
So what did you do Rochester? just replaced the front and rear motor mounts? is there inserts? or do i just buy good used low mileage motor mounts from the junk yard or something?
i thought i read somewhere you take off the motor mounts, depress the rubber and the metal ring.. and press in the ES motor mounts...
i wish there were just inserts..
I had the front and rear mount inserts replaced with ES bushings; (in reality, the side-mounts since our FWD engine is sideways.) For me, the knocking went away just like that. Gone.
Of course, I've got this visceral vibration now, but I rather like that.
You have an automatic, however, and the mounts are different. You're going to have to research the AT mounts.
10-28-2009, 04:37 PM
#5
Under load, the engine will lift. Your original mount inserts are getting less ridged with age, so the engine lifts a little more even, thereby moving your exhaust just enough so that the resonance causes it to bang against something. Or so the theory goes... I'm not a mechanic.
I had the front and rear mount inserts replaced with ES bushings; (in reality, the side-mounts since our FWD engine is sideways.) For me, the knocking went away just like that. Gone.
Of course, I've got this visceral vibration now, but I rather like that.
You have an automatic, however, and the mounts are different. You're going to have to research the AT mounts.
I had the front and rear mount inserts replaced with ES bushings; (in reality, the side-mounts since our FWD engine is sideways.) For me, the knocking went away just like that. Gone.
Of course, I've got this visceral vibration now, but I rather like that.
You have an automatic, however, and the mounts are different. You're going to have to research the AT mounts.
i need automatic ones then i suppose..
if anything i'm sure low mileage mounts for the auto would be suffice for awhile ya?
10-28-2009, 04:45 PM
#6
Supporting Maxima.org Member
iTrader: (29)
Join Date: Oct 2005
Location: Middleboro/Carver, Ma
Posts: 4,572
I have polyurethane filled mounts front & back for an auto 5.5 gen. $100 shipped, paypal is Kevgoods@hotmail.com
10-28-2009, 04:55 PM
#7
I have polyurethane filled mounts front & back for an auto 5.5 gen. $100 shipped, paypal is Kevgoods@hotmail.com
Take your time to research mount bushings for the AT 5.5, and lay off the throttle for a while. (Yeah, right
)
10-28-2009, 05:26 PM
#8
actually i have been laying off because of this.. kinda freaks me out..
10-28-2009, 05:28 PM
#9
I have polyurethane filled mounts front & back for an auto 5.5 gen. $100 shipped, paypal is Kevgoods@hotmail.com
how is the vibration problem?
10-28-2009, 06:44 PM
#11
Senior Member
Join Date: Apr 2009
Location: Tucson, AZ
Posts: 388
i have a rear motor mount broken that ive been too poor to fix (dealer wants $330 WTF)
my only problems are some funny sounds between 2000-3000 rpm that you can only hear if you turn off the air and the radio.
my only problems are some funny sounds between 2000-3000 rpm that you can only hear if you turn off the air and the radio.
10-28-2009, 06:47 PM
#12
see my problem is its like knocking like crazy when i'm flooring it...
10-28-2009, 07:58 PM
#14
Your exhaust is slapping the underside of the car. You could possibly adjust how the pipes are hung, but in all likelihood your engine has too much vertical play because of tired engine mount bushings.
What else could it possibly be?
You could install the NWP Torque Link Connector, but I suspect Aaron would suggest you only use that if you had strong mount bushings.
Here's a suggestion: contact Brian Catts at Cattman. If he can't sell you bushings, he'll surely give you good advice.
10-29-2009, 03:01 PM
#18
10-29-2009, 06:13 PM
#19
simliar to your situation?
10-29-2009, 06:46 PM
#20
Whether your exhaust needs adjustment, or the mount bushings are weak with age, or both... regardless, the banging your describing is probably exhaust pipe slapping the floorboards.
I'm curious now to hear to solution. Get her fixed and let us know.
10-29-2009, 07:10 PM
#21
Not the way I remember it. I always felt the knock was a passenger-side thing in the floorboards. But that could all be in my head, making sense of it once the problem was identified. Sorry, I probably just messed you up with that line of thought. Oops.
Whether your exhaust needs adjustment, or the mount bushings are weak with age, or both... regardless, the banging your describing is probably exhaust pipe slapping the floorboards.
I'm curious now to hear to solution. Get her fixed and let us know.
Whether your exhaust needs adjustment, or the mount bushings are weak with age, or both... regardless, the banging your describing is probably exhaust pipe slapping the floorboards.
I'm curious now to hear to solution. Get her fixed and let us know.
i think it may be the mounts.. either way i already sent him money tonight. If its not the problem, which i beg it to be, at least when i do the whole modding that the extra power is held strong with the mounts...
cuz i'm curious as to the fix as well...
i'm wondering if the bearings and hubs need replacing at this age and miles too
10-30-2009, 05:47 AM
#22
If you really got the itch to head things off, then spend a little up-front money at a trusted mechanic for diagnosis on whether its necessary. Because really all you want is peace of mind. It's a lot cheaper if you spend $50 to hear your mechanic say, "Don't worry about it."
10-30-2009, 05:59 AM
#23
this is true..
Well i guess first things first.. mounts... i'm waiting for dood to hit me back cuz i sent him the cash requested..
i guess we'll just start there...like i said i figured that would be a good thing to have any which way i look at it...
Well i guess first things first.. mounts... i'm waiting for dood to hit me back cuz i sent him the cash requested..
i guess we'll just start there...like i said i figured that would be a good thing to have any which way i look at it...
10-30-2009, 07:31 AM
#24
Supporting Maxima.org Member
iTrader: (29)
Join Date: Oct 2005
Location: Middleboro/Carver, Ma
Posts: 4,572
I have several of them, here's a quick faq:
Yes, it's more than likely the exhaust hitting from too much play in the mounts, the fact that you can really FEEL it in the floorboard tells me that, keep in mind allthough I am a mechanic I'm not looking at the car. You can do a visual inspection, from underneath, you must move the thin rubber insulators around and make a very close look at the mount all the way around the inner sleeve. Or you'll know when you do the install, your (Most likely rear) mount will probably have the inner metal sleeve seperated bad.
Correct on the install, auto's may have to snip wires for electronic mounts, preferably close to the mount and then taped. This causes no lights or issues.
I have two sets getting done over the weekend, will have them out by Wednsday, will receive by next weekend.
Quick rundown on install, don't mind the gatorade on my keyboard.
Estimated time is about 1-1.5 hr's for a novice. Have jack/stands/chocks, 17 & 19mm 1/2" sockets & wrenches handy + typical maxima tools. (Pliers, flatheads, 8,10, 12, 14 <-- you won't use most of those but you should have them anyways because you can pull your entire car apart with them)
Safely jack car up & on stands with wheels chocked.
Remove the 4 17mm bolts holding x-member to chassis.
Disconnect any splashield clips/bolts, etc.
Unclip any harness' attaching to the motor mounts (o2 sensor, cps). Auto's must snip & tape wires for electronic mounts, don't worry: no lights.
Get as many 1/2" extensions as you can, you need like 2ft' worth to do this the easier way, and a 17mm. Turn steering wheel all the way to the right. Reach in through driverside wheel well, following tie rod end stick extensions + socket far in and unbolt the rear mount bolt all the way. Alternative is doing it from underneath but it's harder.
Unbolt the front mount from engine bay.
Get underneath again and pull bolts & crossmember.
Swap the new mounts onto the crossmember, preferably on a nice bench or your knees will hurt the next day.
Install the x-member, don't worry, you'll get all the bolts in after a few tries. Don't tighten any yet. Do the 2 long mount bolts first, and be prepared to tilt the engine by pushing up or down on exhaust, pass axle, etc to get the 2nd long bolt in & started. Don't be an idiot and strip the threads because you didn't actually get it in. Then do the 4 others, loose. If you can handle it, final tightening of all 6 bolts should be done with the vehicle on all 4 wheels, getting the front wheels on a little mound or curb can help.
Sorry no FSM's handy, I'll have tourqe specs + FSM pages included with mounts.
Originally Posted by vastmax
are these new? how is the in-cabin vibration? This is my DD and I dont want it to feel/sound like my car is going to fall apart.
Thanks!
Thanks!
Originally Posted by KRRZ350
"I've installed these and the ES inserts quite a few times and everybody is always scared about the vibration etc like you, but then once it's done all they feel is a barely noticeable increased firmness to the normal steering wheel vibration at idle. I actually like it, others like it as well, and I haven't had anybody that was bothered by it at all. It's the same thing with aluminum flywheels, everytime I sell one people are scared it's going to cause there car to drop revs to quickly between shifts, or chatter, but then once they get it on they were like "What was I thinking, I love this thing"
"......and the nice thing is it's the entire mounts, so you just have to unbolt the crossmember & mounts, switch these mounts onto the crossmember, and then re-install crossmember, vs the ES ones which are a PITA to cut & chisel out the old ones and put the new ones in."
"......and the nice thing is it's the entire mounts, so you just have to unbolt the crossmember & mounts, switch these mounts onto the crossmember, and then re-install crossmember, vs the ES ones which are a PITA to cut & chisel out the old ones and put the new ones in."
Explain to me your process to fill these with poly... From what you've written, it just sounds like you drained them them added silicone. What grade silicone did you use?
Originally Posted by KRRZ350
It's not silicone, it's a 2-part urethane casting, 80A hardness shore is perfect. Also, I don't use the liquid filled electronic auto mounts to start with, harder to work with + I don't like to use trashed ones anyways, and those ones are usually trashed. I start with good condition manual ones, they come out as good or better than ES ones and the install for you or whoever does it is sooooo much easier. $100 shipped, paypal is Kevgoods@hotmail.com.
Originally Posted by MidN1te
Sounds awesome! well in my case... do you think its actually the mounts? i ask this because when i floor it i can feel like hard knocking under my foot board and its sometimes when i go over rough roads... i can feel play in the front... but i dont know of the engine and tranny is bouncin up n down or something..
its not the shocks or mounts cuz those have been replaced....
either way i think these are great investments.. but its like, i hope i'm not spending money toward the wrong direction...
How fast can you get them to me?
another question... with them being in, is there any play? rocking? when i drive i want the power to go to the wheels if you know what i mean.. its like when im cruising... and i left of the pedal its like i let off, then a split second the power goes down.. i push the gas and kinda takes the split second to hit again but it feels there is movement in the engine bay.... does sound like mounts huh...
well i'm gonna paypal you the money..
so all i gotta do is unbolt the bolt between the bushing attached to the motor, on front and back.. then just unbolt that cross member? and it just pulls right down?
do you think my knocking is what Rochester was saying? maybe the exhaust is hitting? and bouncing off something?
its not the shocks or mounts cuz those have been replaced....
either way i think these are great investments.. but its like, i hope i'm not spending money toward the wrong direction...
How fast can you get them to me?
another question... with them being in, is there any play? rocking? when i drive i want the power to go to the wheels if you know what i mean.. its like when im cruising... and i left of the pedal its like i let off, then a split second the power goes down.. i push the gas and kinda takes the split second to hit again but it feels there is movement in the engine bay.... does sound like mounts huh...
well i'm gonna paypal you the money..
so all i gotta do is unbolt the bolt between the bushing attached to the motor, on front and back.. then just unbolt that cross member? and it just pulls right down?
do you think my knocking is what Rochester was saying? maybe the exhaust is hitting? and bouncing off something?
Correct on the install, auto's may have to snip wires for electronic mounts, preferably close to the mount and then taped. This causes no lights or issues.
I have two sets getting done over the weekend, will have them out by Wednsday, will receive by next weekend.
Quick rundown on install, don't mind the gatorade on my keyboard.
Estimated time is about 1-1.5 hr's for a novice. Have jack/stands/chocks, 17 & 19mm 1/2" sockets & wrenches handy + typical maxima tools. (Pliers, flatheads, 8,10, 12, 14 <-- you won't use most of those but you should have them anyways because you can pull your entire car apart with them)
Safely jack car up & on stands with wheels chocked.
Remove the 4 17mm bolts holding x-member to chassis.
Disconnect any splashield clips/bolts, etc.
Unclip any harness' attaching to the motor mounts (o2 sensor, cps). Auto's must snip & tape wires for electronic mounts, don't worry: no lights.
Get as many 1/2" extensions as you can, you need like 2ft' worth to do this the easier way, and a 17mm. Turn steering wheel all the way to the right. Reach in through driverside wheel well, following tie rod end stick extensions + socket far in and unbolt the rear mount bolt all the way. Alternative is doing it from underneath but it's harder.
Unbolt the front mount from engine bay.
Get underneath again and pull bolts & crossmember.
Swap the new mounts onto the crossmember, preferably on a nice bench or your knees will hurt the next day.
Install the x-member, don't worry, you'll get all the bolts in after a few tries. Don't tighten any yet. Do the 2 long mount bolts first, and be prepared to tilt the engine by pushing up or down on exhaust, pass axle, etc to get the 2nd long bolt in & started. Don't be an idiot and strip the threads because you didn't actually get it in. Then do the 4 others, loose. If you can handle it, final tightening of all 6 bolts should be done with the vehicle on all 4 wheels, getting the front wheels on a little mound or curb can help.
Sorry no FSM's handy, I'll have tourqe specs + FSM pages included with mounts.
Last edited by KRRZ350; 10-30-2009 at 07:34 AM.
10-30-2009, 02:34 PM
#26
Under load, the engine will lift. Your original mount inserts are getting less ridged with age, so the engine lifts a little more even, thereby moving your exhaust just enough so that the resonance causes it to bang against something. Or so the theory goes... I'm not a mechanic.
I had the front and rear mount inserts replaced with ES bushings; (in reality, the side-mounts since our FWD engine is sideways.) For me, the knocking went away just like that. Gone.
Of course, I've got this visceral vibration now, but I rather like that.
You have an automatic, however, and the mounts are different. You're going to have to research the AT mounts.
I had the front and rear mount inserts replaced with ES bushings; (in reality, the side-mounts since our FWD engine is sideways.) For me, the knocking went away just like that. Gone.
Of course, I've got this visceral vibration now, but I rather like that.
You have an automatic, however, and the mounts are different. You're going to have to research the AT mounts.
This is also AT with headers on the dyno machine with stock engine mounts you will see just how much the engine lifts under WOT, with the ES bushing in place the engine has no movement at all.
10-30-2009, 03:42 PM
#28
SERIOUSLY hahahaha i was like...umm... nothing's happening...............then BAM! hahahaha....
Sheesh!!! my engine moved like that when i had the car parked, ebrake on, in drive with the brake on and i would jab the gas and it rocks like that.. even worse i think...
not sure if its normal because i know at idle the liquid is soft.. but when pushed, it hardens up....
welp.. thats a convincer for me...
now i just gotta wait LOL!!!!
Sheesh!!! my engine moved like that when i had the car parked, ebrake on, in drive with the brake on and i would jab the gas and it rocks like that.. even worse i think...
not sure if its normal because i know at idle the liquid is soft.. but when pushed, it hardens up....
welp.. thats a convincer for me...
now i just gotta wait LOL!!!!
10-30-2009, 04:22 PM
#29
Thought the visual would convince you, here's the two videos that convinced me, The first one is in desperate need of some ES bushings before the engine climbs straight out - The second video is a 5.5 gen 6spd manual, headers a whole mess of other stuff on the dyno for a bit of fine tuning it has the ES bushings installed and you will see no movement
first vid lots of movement:
http://upload.streetfire.net/video/S...yno_111916.htm
one very sweet 5.5 6spd manual no movement:
http://www.youtube.com/watch?v=us7FO-AhN64
first vid lots of movement:
http://upload.streetfire.net/video/S...yno_111916.htm
one very sweet 5.5 6spd manual no movement:
http://www.youtube.com/watch?v=us7FO-AhN64
Last edited by Ghost_54; 10-30-2009 at 04:31 PM.
10-30-2009, 04:24 PM
#30
exhaust hanger in front of the cat.
If you snip the engine mount wires, disconnect the battery first, or you will blow a fuse. Been there done that.
that's a really hot maxima in the second vid
If you snip the engine mount wires, disconnect the battery first, or you will blow a fuse. Been there done that.
that's a really hot maxima in the second vid
Last edited by knight_yyz; 10-30-2009 at 04:30 PM.
10-30-2009, 07:40 PM
#31
Also that is very convincing.. even though that was a sentra but i see the point...
man i hope i can put down some good numbers lol
10-30-2009, 07:41 PM
#32
OH and Knight.. you said you had a bad wheel bearing.. wat were your symptoms? sounds? feel like something is loose at the suspension? humming noise? thinking of replacing my hubs and bearings..
10-31-2009, 05:17 AM
#34
but that's in due time... first i wanna make sure the mounts fix my issue...
did you by any chance dyno the headers and bolts on FIRST before you tuned? becuase i'm wondering how much more power did the tune make after the initial install of headers and stuff.
10-31-2009, 05:49 AM
#35
I'm using sarcasm to make a point. Can you tell?
10-31-2009, 07:41 AM
#37
10-31-2009, 09:16 AM
#39
I have had to replace my wheel bearings and the symptom for me was the humming noise, not so noticable under 40km but the humming sound would increase as the speed increased.
10-31-2009, 09:30 AM
#40