Mystery rattle on acceleration in the 1.8k - 2.1k RPM range
#1
Mystery rattle on acceleration in the 1.8k - 2.1k RPM range
Hey all, I did some searching and noticed that others experienced the same issue, but haven't found a definitive answer to it. When the car is warmed up, I get a rattle/pinging in the 1.8k-2.1k range and cannot find the source. My mechanic suggested that it was the precats so I had them gutted and the sound remains (the rattle did not increase or decrease in sound after the gut job).
I know Rochester found the source to his rattle with an idler pulley, but his rattle was was down in the RPM range so I wouldn't think it is that.
And ideas? It only does it when the car is fully warmed up.
I know Rochester found the source to his rattle with an idler pulley, but his rattle was was down in the RPM range so I wouldn't think it is that.
And ideas? It only does it when the car is fully warmed up.
#3
Sounds like you've got a good mechanic. Get in the car, put it up on the lift (enjoy the ride, LOL) and goose the throttle while he puts a listening device in various areas. You should be able to find it.
Could be the AC compressor pulley, too.
Could be the AC compressor pulley, too.
#4
Unfortunately, it only happens when accelerating. I can't get it to rattle when at a standstill.
#11
Like most are saying, check to see if the muffler is hitting the heat shield. Im having the same vibration sound while driving at low rpms. I tried to bend the shield up with a crow bar but its still not enough.. might have to cut that biiiaacchhh.
#12
#13
#14
If its carbon, its creating hot spots that you might not be able to overcome with octane or timing. Have you tried running some Seafoam through the engine? Its cheap so its worth at least trying.
#15
Yeah, I ran Seafoam a couple of times and just ran the 3M fuel system kit two weeks ago.
#16
So... AC Compressor and/or AC pulley? I had sold my Max to merovi a few months after getting the idler pulley replaced, and while that (finally) took care of 80-90% of what I was hearing as a rattle, I believe he pin-pointed the remaining noise to the AC. Can't recall what he did, though... whole compressor or just pulley.
#17
I figured you had tried that. You've been around here long enough to know most of this stuff.
So... AC Compressor and/or AC pulley? I had sold my Max to merovi a few months after getting the idler pulley replaced, and while that (finally) took care of 80-90% of what I was hearing as a rattle, I believe he pin-pointed the remaining noise to the AC. Can't recall what he did, though... whole compressor or just pulley.
So... AC Compressor and/or AC pulley? I had sold my Max to merovi a few months after getting the idler pulley replaced, and while that (finally) took care of 80-90% of what I was hearing as a rattle, I believe he pin-pointed the remaining noise to the AC. Can't recall what he did, though... whole compressor or just pulley.
I will have to see about the pulley. I wouldn't imagine it being the issue, but you never know.
#22
-passenger side inner cv joint?
-main chain tensioner weak/clogged?
-AC pulley makes sense, but that would be constant, not only on acceleration.
-by your description it doesn't seem like a heat shield.
valve shims on cylinder 1 or 2?
-main chain tensioner weak/clogged?
-AC pulley makes sense, but that would be constant, not only on acceleration.
-by your description it doesn't seem like a heat shield.
valve shims on cylinder 1 or 2?
#24
#25
---I didn't say a consistent noise that doesn't change speed or decibels... but if the pulley bearings are bad it seems to me that it would make constant noise no matter the RPM unless other noises from the engine counterbalance the frequency of said noise at a lower or higher RPM... thoughts? idc really
overall... I lean towards valve shims on cylinders 1 &/or 2 OR a sloppy main chain tensioner
I forget, does it make the rattle at idle when u reach that RPM range?
drive with your window down on the passenger side next to a wall/building... listen for if the noise is noticeable at shift change intervals and upon every time you apply more throttle. Sometimes you THINK you only hear it during certain RPMs when it happens more than you realize.
#26
Um hmm.
#27
#28
I think valve shims, going after the timing chain, and gutting the pre-cats are all complex solutions for what is more often than not a simple problem.
Want to rule out (or pinpoint) your AC, Alt and tensioner pulleys? Remove the belt.
Want to rule out (or pinpoint) your AC, Alt and tensioner pulleys? Remove the belt.
#29
For me, its the same unwaivering rattling tone at the said rpms. It doesn't increase or decrease with rpms.
If in fact this noise is the shims, then it kinda bums me out because it doesn't seem like a simple fix.
#30
Hey all, I did some searching and noticed that others experienced the same issue, but haven't found a definitive answer to it. When the car is warmed up, I get a rattle/pinging in the 1.8k-2.1k range and cannot find the source. My mechanic suggested that it was the precats so I had them gutted and the sound remains (the rattle did not increase or decrease in sound after the gut job).
I know Rochester found the source to his rattle with an idler pulley, but his rattle was was down in the RPM range so I wouldn't think it is that.
And ideas? It only does it when the car is fully warmed up.
I know Rochester found the source to his rattle with an idler pulley, but his rattle was was down in the RPM range so I wouldn't think it is that.
And ideas? It only does it when the car is fully warmed up.
#32
from RB26 maxima thread:
As for the knocking, does it get worse as the motor revs up?
Have you let the motor warm up to operating temperature?
Are you sure its a "knocking" sound?
What do you have timing set at?
This may be farfetched, but maybe at some point the motor skipped a tooth on the timing chain, maybe the knocking sound may be just the chain itself? Just throwing different ideas out there! It should be worth it to check out the cam gears to make sure that everything is lined up where its suposed to be, its as easy as taking off the valve cover.
******I know on the VQ we have really bad problems with our timing chain tensioners that cause a knocking or rattling noise, i know i have sometimes confused this with other engine related noises. 99% of the time the sound will subside considerably or go away completely once the motor warms up to operating temperature.*********
You may also want to try to record the sound and post it up, we maybe able to have a better idea. Just a thought.
Have you let the motor warm up to operating temperature?
Are you sure its a "knocking" sound?
What do you have timing set at?
This may be farfetched, but maybe at some point the motor skipped a tooth on the timing chain, maybe the knocking sound may be just the chain itself? Just throwing different ideas out there! It should be worth it to check out the cam gears to make sure that everything is lined up where its suposed to be, its as easy as taking off the valve cover.
******I know on the VQ we have really bad problems with our timing chain tensioners that cause a knocking or rattling noise, i know i have sometimes confused this with other engine related noises. 99% of the time the sound will subside considerably or go away completely once the motor warms up to operating temperature.*********
You may also want to try to record the sound and post it up, we maybe able to have a better idea. Just a thought.
#35
#38
#39
Hey all, I did some searching and noticed that others experienced the same issue, but haven't found a definitive answer to it. When the car is warmed up, I get a rattle/pinging in the 1.8k-2.1k range and cannot find the source. My mechanic suggested that it was the precats so I had them gutted and the sound remains (the rattle did not increase or decrease in sound after the gut job).
I know Rochester found the source to his rattle with an idler pulley, but his rattle was was down in the RPM range so I wouldn't think it is that.
And ideas? It only does it when the car is fully warmed up.
I know Rochester found the source to his rattle with an idler pulley, but his rattle was was down in the RPM range so I wouldn't think it is that.
And ideas? It only does it when the car is fully warmed up.
So, now what? I get that slight purr, also! I took it to a mechanic and he could not discern the noise, but I hear it all the time. I definitely hear it more on the passenger side ...
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5th Generation Maxima (2000-2003)
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10-02-2015 08:56 AM