Growning/Growling Sound When GS430 is on steep downhills
01-11-13, 10:53 PM
#1
Instructor
Thread Starter
Growning/Growling Sound When GS430 is on steep downhills
Hi guys,
I'm chasing this really weird problem. For a while I thought it was my brakes groaning when hitting the brakes while going down steep hills.
Well, today I was parked on a steep downhill. I started the car and heard the exact same noise before the car started moving.
It's like the motor mounts are shot or something and the engine is tilting forward. I just don't know what the heck could be coming into contact to be making that groaning sound. I suppose if your engine tilts, it can put stress on the tranny/driveshaft perhaps?
Also, If I mash the gas from a standstill I seem to get this minor jerk.
Agree it's a motor mount problem?
Edit: Sorry about the misspelling in the title: Groaning
I'm chasing this really weird problem. For a while I thought it was my brakes groaning when hitting the brakes while going down steep hills.
Well, today I was parked on a steep downhill. I started the car and heard the exact same noise before the car started moving.
It's like the motor mounts are shot or something and the engine is tilting forward. I just don't know what the heck could be coming into contact to be making that groaning sound. I suppose if your engine tilts, it can put stress on the tranny/driveshaft perhaps?
Also, If I mash the gas from a standstill I seem to get this minor jerk.
Agree it's a motor mount problem?
Edit: Sorry about the misspelling in the title: Groaning
Last edited by BayAreaLex; 02-04-13 at 08:04 PM.
01-12-13, 02:30 AM
#2
Well, not sure if it's motor mounts but that is easy to check. While someone else is in the car with the brakes on and in gear look at the motor mounts while they gas the engine. You will see the motor lift off the mount (look at the driver's side mount). The motor mounts are a well known weakness after a 100k or so
https://www.clublexus.com/forums/per...or-mounts.html
https://www.clublexus.com/forums/2ge...-bushings.html
https://www.clublexus.com/forums/sus...or-mounts.html
https://www.clublexus.com/forums/gs-...or-mounts.html
https://www.clublexus.com/forums/gs-...braking-2.html
D
https://www.clublexus.com/forums/gs-...front-end.html
https://www.clublexus.com/forums/per...or-mounts.html
https://www.clublexus.com/forums/2ge...-bushings.html
https://www.clublexus.com/forums/sus...or-mounts.html
https://www.clublexus.com/forums/gs-...or-mounts.html
https://www.clublexus.com/forums/gs-...braking-2.html
D
https://www.clublexus.com/forums/gs-...front-end.html
Last edited by sam12345; 01-12-13 at 03:10 AM.
01-12-13, 05:25 AM
#3
yeah actually this happened to me too but lemme try and explain briefly.
i was drive down a twisty road to my inlaws, there was a steeep steep hill (downhill mind you). i left offf the throttle and tapped the brake pedal once and than all of a sudden my RPM jumps to like 4k! as i come to the end of the downhill, the rpms even out and all is good.
dont know if this is the same thing your talking about. lol
i was drive down a twisty road to my inlaws, there was a steeep steep hill (downhill mind you). i left offf the throttle and tapped the brake pedal once and than all of a sudden my RPM jumps to like 4k! as i come to the end of the downhill, the rpms even out and all is good.
dont know if this is the same thing your talking about. lol
02-04-13, 08:06 PM
#5
Instructor
Thread Starter
Well, my mechanic said that the motor/tranny mount looked just fine and have no signs of needing replacement.
He pulled off the front brakes, sanded the pads, installed new clips, used anti-squeal... NO change.
We are back to thinking that it could be motor mounts.
He pulled off the front brakes, sanded the pads, installed new clips, used anti-squeal... NO change.
We are back to thinking that it could be motor mounts.
02-05-13, 07:09 PM
#6
Racer
Did You Check Your transmission Fluid? Certain cars make a pronounced whining, groaning sound when low on Fluid at idle or moving. When you are downhill the fluid is uneven and probably not pumping fluid thru the transmission especialy when low. Low fluid would cause transmission skipping.
Hi guys,
I'm chasing this really weird problem. For a while I thought it was my brakes groaning when hitting the brakes while going down steep hills.
Well, today I was parked on a steep downhill. I started the car and heard the exact same noise before the car started moving.
It's like the motor mounts are shot or something and the engine is tilting forward. I just don't know what the heck could be coming into contact to be making that groaning sound. I suppose if your engine tilts, it can put stress on the tranny/driveshaft perhaps?
Also, If I mash the gas from a standstill I seem to get this minor jerk.
Agree it's a motor mount problem?
Edit: Sorry about the misspelling in the title: Groaning
I'm chasing this really weird problem. For a while I thought it was my brakes groaning when hitting the brakes while going down steep hills.
Well, today I was parked on a steep downhill. I started the car and heard the exact same noise before the car started moving.
It's like the motor mounts are shot or something and the engine is tilting forward. I just don't know what the heck could be coming into contact to be making that groaning sound. I suppose if your engine tilts, it can put stress on the tranny/driveshaft perhaps?
Also, If I mash the gas from a standstill I seem to get this minor jerk.
Agree it's a motor mount problem?
Edit: Sorry about the misspelling in the title: Groaning
Last edited by JLAWS; 02-05-13 at 07:13 PM.
02-05-13, 08:42 PM
#7
Lead Lap
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yeah actually this happened to me too but lemme try and explain briefly.
i was drive down a twisty road to my inlaws, there was a steeep steep hill (downhill mind you). i left offf the throttle and tapped the brake pedal once and than all of a sudden my RPM jumps to like 4k! as i come to the end of the downhill, the rpms even out and all is good.
dont know if this is the same thing your talking about. lol
i was drive down a twisty road to my inlaws, there was a steeep steep hill (downhill mind you). i left offf the throttle and tapped the brake pedal once and than all of a sudden my RPM jumps to like 4k! as i come to the end of the downhill, the rpms even out and all is good.
dont know if this is the same thing your talking about. lol
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03-05-13, 12:41 PM
#8
Instructor
Thread Starter
Well, it doesn't look to be the brakes and the Lexus dealer said the transmission fluid level is normal.
I'm biting the bullet and replacing the engine/tranny mounts tomorrow.
I'm biting the bullet and replacing the engine/tranny mounts tomorrow.
03-05-13, 01:16 PM
#9
it might be that you need to grease your sway bar bushings.... as you slow down and take a turn whilst going downhill, the body roll as well as the shift in weight will cause the bar to flex, and if the bushing isn't well greased (like mine which are poly), it will groan/moan...
might be a cheap fix for you... give it a try...
might be a cheap fix for you... give it a try...
03-06-13, 01:33 PM
#10
Instructor
Thread Starter
it might be that you need to grease your sway bar bushings.... as you slow down and take a turn whilst going downhill, the body roll as well as the shift in weight will cause the bar to flex, and if the bushing isn't well greased (like mine which are poly), it will groan/moan...
might be a cheap fix for you... give it a try...
might be a cheap fix for you... give it a try...
As noted above, I can create the noise while parked on a very steep downhill with the car not even moving. That's the primary clue that makes me rule out suspension and brakes. But then again, stranger things have happened.
I will report my impressions back soon.
03-06-13, 07:13 PM
#11
Instructor
Thread Starter
Ok guys, so today I had the sway bar bushings replaced even though the old ones looked perfect when removed.
Both the Lexus dealer and my independent mechanic said my motor mounts looked fine and they didn't see anything wrong. I ordered OEM motor mounts from Sewell along with the OEM tranny mount and asked my mechanic to replace them anyway.
Upon removing the driver side motor mount, we found this:
Not only was this the cause of the groaning when braking, but it was also a major source of my front end clunking as the engine was allowed to hop up and down when hitting bumps.
In summary, if your car has a slight hesitation at idle, groans when braking, or has front end clunk when going over bumps and you can't seem to identify any sources coming from the suspension/brakes, look at the motor/tranny mounts (especially that driver side mount)!
Today is a good day :-)
Both the Lexus dealer and my independent mechanic said my motor mounts looked fine and they didn't see anything wrong. I ordered OEM motor mounts from Sewell along with the OEM tranny mount and asked my mechanic to replace them anyway.
Upon removing the driver side motor mount, we found this:
Not only was this the cause of the groaning when braking, but it was also a major source of my front end clunking as the engine was allowed to hop up and down when hitting bumps.
In summary, if your car has a slight hesitation at idle, groans when braking, or has front end clunk when going over bumps and you can't seem to identify any sources coming from the suspension/brakes, look at the motor/tranny mounts (especially that driver side mount)!
Today is a good day :-)
03-07-13, 04:58 AM
#13
So you are telling me that neither the Lexus dealer or your mechanic could tell that the motor mounts were bad by "looking at the motor mount as another person puts his foot on the brake and puts the transmission in drive and accelerates"? And when you jack the car up and down " if the motor does not move like it is a bowl of jelly your motor mounts are bad".
I think I would find a different dealer and mechanic. Now that you have the new motor mounts jack the car up and down and observe the oil pan as you do this. Tell me what you see. Very simple test. You could have known your issue 2 months ago
https://www.clublexus.com/forums/sus...ml#post7703504
My post just above yours. (post#48)
I think I would find a different dealer and mechanic. Now that you have the new motor mounts jack the car up and down and observe the oil pan as you do this. Tell me what you see. Very simple test. You could have known your issue 2 months ago
https://www.clublexus.com/forums/sus...ml#post7703504
My post just above yours. (post#48)
Last edited by sam12345; 03-07-13 at 05:14 AM.
03-07-13, 10:41 AM
#14
Instructor
Thread Starter
Sam, believe me, I'm also scratching my head wondering how it took this long to diagnose the problem. I've been chasing these issues for a solid 6 months. Granted during that time, a bunch of other worn items were replaced which needed to be replaced anyway.
Although I had my suspicions that the motor mounts could be the culprit, when two mechanics (one of which is the dealer) are telling you that the mounts are fine, you definitely second guess yourself and that's why I spent so much time looking at the suspension/brakes instead. It's concerning and terrible in terms of inspiring confidence in my mechanics when something of this magnitude is overlooked. My mechanic is a 15yr veteran and has the reputation in my area as the guy to take your car to. Needless to say, he was a bit embarrassed and praised me for pushing him to address something he missed.
To answer your question, when I jacked up the car, I could not see anything overly obvious in terms of motor shaking excessively like you describe as a "bowl of jelly." Remember, the passenger side mount and the transmission mount were in great shape and still holding things together. But admittedly I don't have a very good point of reference for what was normal and what wasn't.
In any case, here is what I notice with the new mounts:
- The idle is silky smooth. I can hardly tell the car is on. With the bad mount, there was an unmistakable subtle vibe/hesitation at idle.
- With the broken mount I would get a jerk/thud from the rear differential when accelerating hard from a stop. That's gone. It must have had something to do with the motor torquing over and whipping back transferring that energy to the rear.
- Groaning when braking or when parked on steep hills is gone.
- The front end clunk when going over bumps is gone.
It's amazing what level of problems a split mount can create that all look like other things. Based on my bullet points above, you can see how easy it is to mistake the suspension/brakes as the culprit for some of these symptoms.
Although I had my suspicions that the motor mounts could be the culprit, when two mechanics (one of which is the dealer) are telling you that the mounts are fine, you definitely second guess yourself and that's why I spent so much time looking at the suspension/brakes instead. It's concerning and terrible in terms of inspiring confidence in my mechanics when something of this magnitude is overlooked. My mechanic is a 15yr veteran and has the reputation in my area as the guy to take your car to. Needless to say, he was a bit embarrassed and praised me for pushing him to address something he missed.
To answer your question, when I jacked up the car, I could not see anything overly obvious in terms of motor shaking excessively like you describe as a "bowl of jelly." Remember, the passenger side mount and the transmission mount were in great shape and still holding things together. But admittedly I don't have a very good point of reference for what was normal and what wasn't.
In any case, here is what I notice with the new mounts:
- The idle is silky smooth. I can hardly tell the car is on. With the bad mount, there was an unmistakable subtle vibe/hesitation at idle.
- With the broken mount I would get a jerk/thud from the rear differential when accelerating hard from a stop. That's gone. It must have had something to do with the motor torquing over and whipping back transferring that energy to the rear.
- Groaning when braking or when parked on steep hills is gone.
- The front end clunk when going over bumps is gone.
It's amazing what level of problems a split mount can create that all look like other things. Based on my bullet points above, you can see how easy it is to mistake the suspension/brakes as the culprit for some of these symptoms.
Last edited by BayAreaLex; 03-07-13 at 10:54 AM.
03-07-13, 09:18 PM
#15
Sam, believe me, I'm also scratching my head wondering how it took this long to diagnose the problem. I've been chasing these issues for a solid 6 months. Granted during that time, a bunch of other worn items were replaced which needed to be replaced anyway.
Although I had my suspicions that the motor mounts could be the culprit, when two mechanics (one of which is the dealer) are telling you that the mounts are fine, you definitely second guess yourself and that's why I spent so much time looking at the suspension/brakes instead. It's concerning and terrible in terms of inspiring confidence in my mechanics when something of this magnitude is overlooked. My mechanic is a 15yr veteran and has the reputation in my area as the guy to take your car to. Needless to say, he was a bit embarrassed and praised me for pushing him to address something he missed.
To answer your question, when I jacked up the car, I could not see anything overly obvious in terms of motor shaking excessively like you describe as a "bowl of jelly." Remember, the passenger side mount and the transmission mount were in great shape and still holding things together. But admittedly I don't have a very good point of reference for what was normal and what wasn't.
In any case, here is what I notice with the new mounts:
- The idle is silky smooth. I can hardly tell the car is on. With the bad mount, there was an unmistakable subtle vibe/hesitation at idle.
- With the broken mount I would get a jerk/thud from the rear differential when accelerating hard from a stop. That's gone. It must have had something to do with the motor torquing over and whipping back transferring that energy to the rear.
- Groaning when braking or when parked on steep hills is gone.
- The front end clunk when going over bumps is gone.
It's amazing what level of problems a split mount can create that all look like other things. Based on my bullet points above, you can see how easy it is to mistake the suspension/brakes as the culprit for some of these symptoms.
Although I had my suspicions that the motor mounts could be the culprit, when two mechanics (one of which is the dealer) are telling you that the mounts are fine, you definitely second guess yourself and that's why I spent so much time looking at the suspension/brakes instead. It's concerning and terrible in terms of inspiring confidence in my mechanics when something of this magnitude is overlooked. My mechanic is a 15yr veteran and has the reputation in my area as the guy to take your car to. Needless to say, he was a bit embarrassed and praised me for pushing him to address something he missed.
To answer your question, when I jacked up the car, I could not see anything overly obvious in terms of motor shaking excessively like you describe as a "bowl of jelly." Remember, the passenger side mount and the transmission mount were in great shape and still holding things together. But admittedly I don't have a very good point of reference for what was normal and what wasn't.
In any case, here is what I notice with the new mounts:
- The idle is silky smooth. I can hardly tell the car is on. With the bad mount, there was an unmistakable subtle vibe/hesitation at idle.
- With the broken mount I would get a jerk/thud from the rear differential when accelerating hard from a stop. That's gone. It must have had something to do with the motor torquing over and whipping back transferring that energy to the rear.
- Groaning when braking or when parked on steep hills is gone.
- The front end clunk when going over bumps is gone.
It's amazing what level of problems a split mount can create that all look like other things. Based on my bullet points above, you can see how easy it is to mistake the suspension/brakes as the culprit for some of these symptoms.
Here is my direct quote
"When I jack up or down my car from the front, using a floor jack, I can visibly see the motor moving with each pump of the jack (like the motor is in jellloten) this is how it is suppose to move (I have brand new motor mounts) if the motor does not move in this fashion I suspect your motor mounts are toast. Change the tranny mount while you are at it. By the way I gained acceleration (0 to 60 full throttle) with the new motor mounts, probably due to quicker and smoother shifting. Car will also feel like higher quality. But I never had a clunk and mine were sheared in half, completely sheared, but my tranny mount was good so that may be why no clunk"
Anyways, I am glad you got them fixed. Also if you tested your acceleration before you should notice some improvement (I did) because the shifting is quicker.
Last edited by sam12345; 03-07-13 at 09:22 PM.