Knocking noise while in gear
- Thread starter marknor2002
- Start date
AntleredRuin
New member
I have this on my 99 and have had it since I bought it 90k and 5 years ago. Mine is a bad pulley on the compressor. I took the AC belt off and the noise goes away entirely. So not dangerous at all, just annoying until you get used to it. Not worth the fight removing the compressor to replace the pulley, discharge and recharge freon, etc. I'll just leave it till it really breaks.
MrRaspberryJam95
New member
Yeah I feel the same way, no matter what i always say it’s a 20+ year old car and I’ve got 217k miles on mine it’s gonna make noise
I'm reviving this to see if anyone figured out exactly what the issue was?
Was this the noise, guys?
https://www.youtube.com/watch?v=zE6zf1XVX3o&feature=youtu.be
* Noise only occurs in gear once warm
* On the first start up, rarely, the noise does not occur until you goose the gas a bit in gear with your foot on the brake. This starts the noise occurring and it won't go away after it starts.
* My flexplate and bolts looked perfectly fine, bolts were tight.
The problem is not caused by any of the following:
1) The rod bearings (replaced mine, no change).
2) Crankshaft end play (measured mine, well within Toyota spec)
3) The water pump, timing belt, timing belt tensioner, timing belt tensioner pulley, or timing belt idler pulleys (replaced mine, no change).
4) The AC compressor pulley bearing (replaced mine, no change)
5) The V belt tensioner pulley (replaced mine, no change)
6) The V belts (replaced mine, no change)
Was this the noise, guys?
https://www.youtube.com/watch?v=zE6zf1XVX3o&feature=youtu.be
* Noise only occurs in gear once warm
* On the first start up, rarely, the noise does not occur until you goose the gas a bit in gear with your foot on the brake. This starts the noise occurring and it won't go away after it starts.
* My flexplate and bolts looked perfectly fine, bolts were tight.
The problem is not caused by any of the following:
1) The rod bearings (replaced mine, no change).
2) Crankshaft end play (measured mine, well within Toyota spec)
3) The water pump, timing belt, timing belt tensioner, timing belt tensioner pulley, or timing belt idler pulleys (replaced mine, no change).
4) The AC compressor pulley bearing (replaced mine, no change)
5) The V belt tensioner pulley (replaced mine, no change)
6) The V belts (replaced mine, no change)
It does kind of sound like that at first, or the timing belt hitting the plastic timing cover, but it isn't. The more you listen to it, the more it appears to be a metallic sound.
The fan clutch seems fine and fan bearing has zero play. Stethoscope is very vague and generalized, but it seems to be coming from the front of the engine somewhere. I could be totally wrong though.
you said you got it narrowed down to front of engine, so that eliminates flex plate. It is a bit of a hassle, but take off one belt at a time and see if noise goes away. I had a bad ac idler pulley one time, but that was not a ticking sound, but until I pulled the belts off I was not able to isolate it and my brain was going worse case situations. The idler pulley spins and can make noise even if ac is off and ac clutch is not engaged.
what about harmonic balancer ?
just brainstorming
what about harmonic balancer ?
just brainstorming
Mine has developed this noise.
Only happens once the truck is warm, like after driving for a while. A/C on or Off doesnt matter.
It is a definite metal tap/clunk noise that is affected by engine speed. Sometimes it's quite loud, others its not. Only happens at and just above idle, it either goes away or is drowned out at higher RPMs.
Still get same power, mpgs, and no drivability issues.
:sobbing:
Only happens once the truck is warm, like after driving for a while. A/C on or Off doesnt matter.
It is a definite metal tap/clunk noise that is affected by engine speed. Sometimes it's quite loud, others its not. Only happens at and just above idle, it either goes away or is drowned out at higher RPMs.
Still get same power, mpgs, and no drivability issues.
:sobbing:
tx_shooter
New member
I had a similar strange metallic knocking that only happened when in gear. It ended up being the exhaust system contacting the transmission. I could not reproduce the sound when sitting in Park; but ended up having my wife hold the 4R in Drive while I listened from the side. Once I replaced the exhaust system the rattle and knocking stopped. Apparently the mount rubbers were broken down allowing for extra movement and the muffler had a large amount of rusted internals allowing for a rattle or knocking depending on RPMs.
I just checked mine again. The exhaust isnt touching anything. Engine idles so smooth that it doesnt even shimmy a little.
However I noticed it makes the noise at idle in or out of gear, a/c on or off, and continues as I rev the engine a small bit, then I cant hear it.
Sounds like its coming from the rear of the engine, easier to hear from below.
Can anyone else verify that they have the same knocking noise as I posted in this video? https://www.youtube.com/watch?v=zE6zf1XVX3o&feature=youtu.be
Here's more information: the noise "goes away" when ANY ONE OR MORE of the three accessory drive belts are removed.
For example, if I remove only the power steering belt, the noise goes away. If I put the power steering belt back on, the noise comes back. If I then remove the AC belt, the noise goes away. And so on.
Here is a video with clearer audio: https://www.youtube.com/watch?v=1wF51unJnUo&feature=youtu.be
Here's more information: the noise "goes away" when ANY ONE OR MORE of the three accessory drive belts are removed.
For example, if I remove only the power steering belt, the noise goes away. If I put the power steering belt back on, the noise comes back. If I then remove the AC belt, the noise goes away. And so on.
Here is a video with clearer audio: https://www.youtube.com/watch?v=1wF51unJnUo&feature=youtu.be
jgue467
Senior Member
yeah mine with 330K does it. I really only hear it inside with doors/windows closed. In park/neutral, there is a rythmic 'tap, tap, tap' like yours, increase rpms a bit and the rate of taps increases. Can hear it in gear too, don't really hear it while driving, probably drowned out.
My mechanic checked the same things, flex plate so forth, found nothing. Said it is internal but not sure what, just keep driving it he said.
I drive it to deer lease every other weekend, 75mph up and down central texas hills, 150 miles round trip, i turn OD off up hills and it just responds, runs great. I'll just keep maintaining it....
My mechanic checked the same things, flex plate so forth, found nothing. Said it is internal but not sure what, just keep driving it he said.
I drive it to deer lease every other weekend, 75mph up and down central texas hills, 150 miles round trip, i turn OD off up hills and it just responds, runs great. I'll just keep maintaining it....
Hey SigSaucer, I have noticed this identical issue today on my 02 4runner 4wd. Did you end up finding a solution?
So I'm currently having a knocking issue and it sounds kinda all around the engine and it changes with symptoms that others have described but I do know that my muffler is rusted out and sounds like crap. Is there any way you could post some pictures of the parts you're talking about in your response?
