Engine Vibration at 3k RPM
09-20-2019, 07:26 PM
#1
Engine Vibration at 3k RPM
Hi All,
Looking to track down an issue. I've scoured the web and found only a few leads, most of which I've tried.
Truck is a 91 Toyota Pickup, 22RE, with 255k miles on the chassis (don't know about motor). The truck runs well and I've done multiple long distance road trips in it with no issues. That said, when I get the RPMs up to about 3000, I start to feel and hear a vibration seemingly coming from the engine bay. I can feel the vibration in the floorboard and in the clutch pedal when shifting. This vibration happens when moving and when stationary, in gear and in neutral. When I have the truck in gear with the clutch in, the vibration starts closer to 2700 RPM.
This issue has been present for as long as I can remember, at least the last couple years of driving. I normally baby my truck though and keep it around 60mph on the freeway, which tends to be just around 2800 RPM on the freeway in 5th gear. When I get up to 3000 RPM, I start to feel the vibration. When going higher than 3000 RPM, it's hard for me to distinguish between road noise and the sound of the vibration, and it's also harder to feel the vibration (so I don't know if it goes away or just becomes less pronounced above 3k RPM).
What I've tried:
-Disconnecting accessory belts (AC, Water pump/alternator, and power steering pumps) and running the truck briefly up to 3000 RPM. There was no noticeable change, and still observed vibrations from engine bay
-Running truck up to 3000 RPM while watching for engine vibration and observing motor mounts. No noticeable movement
-Putting truck in 1st with parking brake on and letting out clutch slightly, having somebody watch for engine mount torquing. No noticeable movement
Could this still be a motor mount issue? Could this be a worn out harmonic balancer that is failing to balance vibrations from the motor?
Thanks for any help!
Looking to track down an issue. I've scoured the web and found only a few leads, most of which I've tried.
Truck is a 91 Toyota Pickup, 22RE, with 255k miles on the chassis (don't know about motor). The truck runs well and I've done multiple long distance road trips in it with no issues. That said, when I get the RPMs up to about 3000, I start to feel and hear a vibration seemingly coming from the engine bay. I can feel the vibration in the floorboard and in the clutch pedal when shifting. This vibration happens when moving and when stationary, in gear and in neutral. When I have the truck in gear with the clutch in, the vibration starts closer to 2700 RPM.
This issue has been present for as long as I can remember, at least the last couple years of driving. I normally baby my truck though and keep it around 60mph on the freeway, which tends to be just around 2800 RPM on the freeway in 5th gear. When I get up to 3000 RPM, I start to feel the vibration. When going higher than 3000 RPM, it's hard for me to distinguish between road noise and the sound of the vibration, and it's also harder to feel the vibration (so I don't know if it goes away or just becomes less pronounced above 3k RPM).
What I've tried:
-Disconnecting accessory belts (AC, Water pump/alternator, and power steering pumps) and running the truck briefly up to 3000 RPM. There was no noticeable change, and still observed vibrations from engine bay
-Running truck up to 3000 RPM while watching for engine vibration and observing motor mounts. No noticeable movement
-Putting truck in 1st with parking brake on and letting out clutch slightly, having somebody watch for engine mount torquing. No noticeable movement
Could this still be a motor mount issue? Could this be a worn out harmonic balancer that is failing to balance vibrations from the motor?
Thanks for any help!
09-20-2019, 09:43 PM
#2
Compression test!
Cylinder imbalance will show this kind of vibration, the higher the RPM the more prominent.
This could also be signs of a misfire, which is also cylinder imbalance but not due to compression always.
If your clutch is disconnected, and your certain its not the rear drive train ( issue happens while stationary ) it's an engine issue and not a drive train imbalance (shaft or tires).
A decent check for the engine mounts (aside from a visual, which you should do) is how far to the right the engine shifts when you goose the throttle. I don't have a number for this you can compare to but it should not be excessive (if it looks wrong, or your see cracks of any sort in the cleaned mounts, replace them.). Verify your stiffeners are in place, they are found at the lower transmission-engine interface on the bell housing and with with the engine mounts to prevent the engine torquing over.
Cylinder imbalance will show this kind of vibration, the higher the RPM the more prominent.
This could also be signs of a misfire, which is also cylinder imbalance but not due to compression always.
If your clutch is disconnected, and your certain its not the rear drive train ( issue happens while stationary ) it's an engine issue and not a drive train imbalance (shaft or tires).
A decent check for the engine mounts (aside from a visual, which you should do) is how far to the right the engine shifts when you goose the throttle. I don't have a number for this you can compare to but it should not be excessive (if it looks wrong, or your see cracks of any sort in the cleaned mounts, replace them.). Verify your stiffeners are in place, they are found at the lower transmission-engine interface on the bell housing and with with the engine mounts to prevent the engine torquing over.
The following users liked this post:
old87yota (09-23-2019)
09-21-2019, 07:22 AM
#3
Compression test!
Cylinder imbalance will show this kind of vibration, the higher the RPM the more prominent.
This could also be signs of a misfire, which is also cylinder imbalance but not due to compression always.
If your clutch is disconnected, and your certain its not the rear drive train ( issue happens while stationary ) it's an engine issue and not a drive train imbalance (shaft or tires).
A decent check for the engine mounts (aside from a visual, which you should do) is how far to the right the engine shifts when you goose the throttle. I don't have a number for this you can compare to but it should not be excessive (if it looks wrong, or your see cracks of any sort in the cleaned mounts, replace them.). Verify your stiffeners are in place, they are found at the lower transmission-engine interface on the bell housing and with with the engine mounts to prevent the engine torquing over.
Cylinder imbalance will show this kind of vibration, the higher the RPM the more prominent.
This could also be signs of a misfire, which is also cylinder imbalance but not due to compression always.
If your clutch is disconnected, and your certain its not the rear drive train ( issue happens while stationary ) it's an engine issue and not a drive train imbalance (shaft or tires).
A decent check for the engine mounts (aside from a visual, which you should do) is how far to the right the engine shifts when you goose the throttle. I don't have a number for this you can compare to but it should not be excessive (if it looks wrong, or your see cracks of any sort in the cleaned mounts, replace them.). Verify your stiffeners are in place, they are found at the lower transmission-engine interface on the bell housing and with with the engine mounts to prevent the engine torquing over.
I will do a compression check and inspect those mounts!
I'm doing a transmission swap with a rebuilt W56C from Marlin Crawler so I may just go through and replace all the mounts then as good measure.
The following users liked this post:
old87yota (09-23-2019)
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