100 Series Intermittent Vibration on Drivers Side

[collk22]

Hey Guys - hope everyone is well and in good spirits. I've been thinking about Dbenke since hearing about the surgery - hope your recovery is going smoothly and is on track.

I'm getting a weird, intermittent vibration on the drivers side of my 100 series at low speeds / rpm (usually in the 1000-1300 rpms range). It happens sporadically while accelerating and while decelerating. The noise is a jackhammer-like burst (albeit lower volume) and I can feel the vibration in the pedals. The truck seems to be driving fine otherwise. Anyone have any ideas on what it could be?

The other day it happened while I was parking and I turned the truck off and jumped out to listen and could hear the vibration occurring after the engine cut off.

The CO forum and 100 series forum haven't been helpful at this point. I'm a little reluctant to take it in at this point or ask for a test drive with a mechanic because I can't really determine when the vibration/noise will show up.

Thanks!

 

[dbenke]

Maybe some kind of air pump, or the brake booster...the 100 series has an electric booster of some kind

 

[CharlestonG8R]

27" spinner rims out of balance?

Stopped and off, but still vibrating... If you'd still been moving I might have suspected a drive shaft out of balance... I'm reaching here, but maybe the fan clutch? Not much is moving when you're parked and off... Any idea where the vibration is coming from?

 

[collk22]

27" spinner rims out of balance?

Stopped and off, but still vibrating... If you'd still been moving I might have suspected a drive shaft out of balance... I'm reaching here, but maybe the fan clutch? Not much is moving when you're parked and off... Any idea where the vibration is coming from?

Drivers side. Maybe the Charcoal canister? Brake booster?

 

[CharlestonG8R]

Charcoal canister - Improbable... It's just an air purifier so you don't smell like gas when you get out of the truck (and allows your tank to vent). No mechanical parts and it wouldn't cause any vibrations.

Brake booster - More likely, I'm not sure of the details on the 100 series brake booster. On the 80, when mine went, it was hissing and the brakes were tough to operate.

Still stuck on what is moving after the vehicle stops. Hrmmmm...

 

[dbenke]

The 80 has a vacuum booster. The 100 series doesn't. @Eliot has a LX470 and it was an electronic booster of some sort. I'm guessing the 100 is the same.

 

[CharlestonG8R]

Did @Eliot 's 100 vibrate?

 

[dbenke]

Not if it was working properly

 

[tabraha]

If it's driver side, can be felt in the pedals and continues when the engine is off that really does sound like the electric booster pump. As it gets older it will have trouble periodically maintaining the pressure and you will feel it running to maintain it. I had mine start a squealing noise before it let go. When it does let go you will get an ABS light and have only the brake pressure your legs (and you will need both legs) can produce. Not a good feeling. Typically not a cheap fix either.

 

[collk22]

If it's driver side, can be felt in the pedals and continues when the engine is off that really does sound like the electric booster pump. As it gets older it will have trouble periodically maintaining the pressure and you will feel it running to maintain it. I had mine start a squealing noise before it let go. When it does let go you will get an ABS light and have only the brake pressure your legs (and you will need both legs) can produce. Not a good feeling. Typically not a cheap fix either.

This makes sense - I notice the problem most when driving around town and there is lots of stop and go.

 

[dbenke]

Glad we could help