Vibration in motor

LAVON7

MEMBER
1996 CHEVROLET TAHOE
5.7L
V8
4WD
AUTOMATIC
180,000 MILES

Hi, my SUV seems to have a jerking motion front to rear when the RPM's are over around 1,500. It feels like it’s in the motor but not sure. I’ve had the injectors and mass air flow sensor replaced recently along with a new air filter and fuel filter and didn’t help. It’s been doing this for a few years but has recently gotten worse. I’ve replaced the plugs and wires around two years ago as well. Any suggestions would be much appreciated!

6 Replies

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

This could be a wheel weight that has been thrown from your tire. When was the last time you had your tires re-balanced. When you purchase your tires a lot of retailers offer lifetime balancing and rotation. There are a couple of other things that could be causing this like u-joints going bad or a wheel bearing going out, but I would start with balancing the tires. Here are a couple of links that might be helpful. Let us know what you find out.

https://www.2carpros.com/articles/how-u-joints-work
https://www.2carpros.com/articles/how-to-replace-front-wheel-bearings-and-seals

Alex,
2CarPros

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Monday, February 4th, 2019 AT 10:32 PM

LAVON7

MEMBER
3 POSTS

Hey Alex, thanks for the input. It’s been doing this for a few years and I have the tires balanced frequently. Do you believe it could be the crankshaft position sensor by chance? It only does this around 1,500 RPM or so. A guy I know has a high end scanner and it showed on a graph that there wasn't much air flowing through the MAF sensor so I replaced it. Still having the issue. Maybe a connector is bad? Again, thanks for your input. I’m at my wits end.

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Tuesday, February 5th, 2019 AT 8:53 PM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello again,

Have you inspected your motor and transmission mounts? Down below I've included a probable diagnosis for your issue and the fix. Let me know what you find out.

Thanks,
Alex,
2CarPros

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Tuesday, February 5th, 2019 AT 10:59 PM

KEN L

MASTER CERTIFIED MECHANIC
47,326 POSTS

If I may jump in here. Can you please shoot a quick video with your phone so we can hear the engine noise? That would be great. You can upload it here with your response. Also, is the vibration notable in park if you rev the engine?

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Wednesday, February 6th, 2019 AT 12:48 PM

LAVON7

MEMBER
3 POSTS

The vibration isn’t going to be noticeable in a video. I wish otherwise. It’s not a violent shake or the like. It’s simply a what seems like a slight front to rear jerk that’s not consistent, unfortunately. When I’m park, I can rev the RPM's and it doesn’t jerk, only under a load (in gear driving). I honestly don’t think it's an engine mount, though. Not rattling or clunking, no noise just the jerking.
Again, I appreciate the help.