Engine Rattle
Thread Starter
Advanced
Joined: Jul 2013
Posts: 88
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Engine Rattle
The engine is rattling on light acceleration. Sometimes it goes away quickly other times if I hold the throttle at the right position it stays. Hard acceleration I hear nothing.
Any thoughts??
Any thoughts??
Melting Slicks
Joined: May 2007
Posts: 3,269
Likes: 25
From: Simi Valley Ca
I read some time ago here that one member had loose bolts where the muffler mounts attach to the frame or something. I'd get it on a lift and see if you can find any loose bolts under the car. It's probably a simple issue.
Race Director
Joined: May 2008
Posts: 10,742
Likes: 629
From: Manheim Pennsylvania
Rattling, what fuel grade are you using? What you describe sounds like detonation caused by low fuel grade or the engine's timing is off. Have your dealer Investigate to determine the cause.
Race Director
Joined: Mar 2010
Posts: 15,993
Likes: 821
Since you are still under your warranty, head into the dealership so they can get an ear on the rattling. If you would like us to contact your dealership first to let them know what is happening, let us know through PM. Include your information, VIN, mileage and dealership.
Happy Super Bowl,
Kelly J.
Chevrolet Customer Care
Instructor
Joined: Dec 2013
Posts: 161
Likes: 0
Hey grandads,
Since you are still under your warranty, head into the dealership so they can get an ear on the rattling. If you would like us to contact your dealership first to let them know what is happening, let us know through PM. Include your information, VIN, mileage and dealership.
Happy Super Bowl,
Kelly J.
Chevrolet Customer Care
Since you are still under your warranty, head into the dealership so they can get an ear on the rattling. If you would like us to contact your dealership first to let them know what is happening, let us know through PM. Include your information, VIN, mileage and dealership.
Happy Super Bowl,
Kelly J.
Chevrolet Customer Care
Does it get any better than that??? 
1st Gear
Joined: Mar 2014
Posts: 1
Likes: 0
Rattle
I have a C7 with 3600 miles and mine is doing the same thing. It sounds like its on drivers side and possibly a heat shield. Somewhere around 1600 and 1800 rpm car in gear and warm. Doesn't seem to do it in neutral only in gear under a load.
Thread Starter
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Joined: Jul 2013
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Update: Went to dealer and had them check it out. They had to call GM engineering. What they found is the serpentine belt tensioner has a small leak in hydraulic fluid. That causes the belt to become loose. The harmonic vibration of the engine during cylinder deactivation at low RPM with little acceleration causes this belt to squeak and rattle.
GM states that they have seen this on a few cars and that they will replace the belt tensioner.
GM states that they have seen this on a few cars and that they will replace the belt tensioner.
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Melting Slicks
Joined: Feb 2014
Posts: 2,406
Likes: 3
From: Austin Texas
NCM Sinkhole Donor
Update: Went to dealer and had them check it out. They had to call GM engineering. What they found is the serpentine belt tensioner has a small leak in hydraulic fluid. That causes the belt to become loose. The harmonic vibration of the engine during cylinder deactivation at low RPM with little acceleration causes this belt to squeak and rattle.
GM states that they have seen this on a few cars and that they will replace the belt tensioner.
GM states that they have seen this on a few cars and that they will replace the belt tensioner.
Advanced
Joined: Feb 2014
Posts: 81
Likes: 0
From: Richland WA
Thank You!
Update: Went to dealer and had them check it out. They had to call GM engineering. What they found is the serpentine belt tensioner has a small leak in hydraulic fluid. That causes the belt to become loose. The harmonic vibration of the engine during cylinder deactivation at low RPM with little acceleration causes this belt to squeak and rattle.
GM states that they have seen this on a few cars and that they will replace the belt tensioner.
GM states that they have seen this on a few cars and that they will replace the belt tensioner.
Racer
Joined: Nov 2013
Posts: 313
Likes: 44
From: Little Rock AR
Yep, that's exactly what's going on with mine.
The seal on the hydraulic tensioner pulley has blown it's seal & now it's make this ticking or rattling noise. You have to hunt for it a little bit with the throttle, but from 1500-2000rpm on up til ???. Almost sounds like an exhaust leak on mine.
Wormwood
The seal on the hydraulic tensioner pulley has blown it's seal & now it's make this ticking or rattling noise. You have to hunt for it a little bit with the throttle, but from 1500-2000rpm on up til ???. Almost sounds like an exhaust leak on mine.
Wormwood
Cruising
Joined: Sep 2009
Posts: 10
Likes: 0
I took my car to the dealer and they replaced the belt tensioner. Rattle went away. The rattle happened only under mild acceleration at 1500 rpm. It was in the engine compartment and sounded like a hard plastic pecking a metal surface. GM engineer solved the case.
Instructor
Joined: Jan 2014
Posts: 183
Likes: 7
From: Texas
Advanced
Joined: Feb 2014
Posts: 81
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From: Richland WA
Cruising
Joined: Sep 2009
Posts: 10
Likes: 0
My car is automatic, but I think this is not relevant.
Good luck.
