Engine Rattle
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
Thanks for posting. Just yesterday driving home, I developed this same rattle with 600 miles on the odometer. Did a search today and found this thread. Going to the dealer next week, will post the results.
Pro
Joined: Feb 2001
Posts: 617
Likes: 22
Racer
Joined: Dec 2013
Posts: 407
Likes: 1
From: Panama City Beach FL
brought my c7 2 weeks ago because I have a raddle, more like ticking aroung 1200 to 3k rpms, corvette dude at dealership is older so he respectfully couldn't hear it.... but it bugs the heck out of me, need to have my screen fixed so I will wait, thanx for the post
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
I got under my car today and even If I was able to locate the rattle, it seem nearly impossible to reach many of the heat shields. I did look at the belt tensioner and it is very hard to get to it but it is directly above the front spring. My front spring does have signs of a fluid leak ( wet spot ) so I 'am hoping that is the problem.
Pro
Joined: Feb 2001
Posts: 617
Likes: 22
Not sure how you can say "At least we know what the problem is" - so far I have read "belt tensioner," "heat shield," "direct injection," etc.??
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
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.
Just returned from the dealer. I was informed that my rattle was a leaky belt tensioner. Part had to be ordered, I was told that it was safe to drive until the part arrives. Just thankful that they found the problem. Thank you for posting and giving the rest of us some idea of what to look for.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Pro
Joined: Jan 2010
Posts: 629
Likes: 65
From: Freedom PA
Would need more accurate info. Never seen a belt tensioner that used hydraulic fluid.
Ed
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
I have to agree with you, but won't say BS. Maybe it's just a misunderstanding between hydraulic fluid, and just a bad seal that allowed grease to leak out of the pulley's bearing.
Would need more accurate info. Never seen a belt tensioner that used hydraulic fluid.
Ed
Would need more accurate info. Never seen a belt tensioner that used hydraulic fluid.
Ed
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
I stand corrected from my last post. Today I returned to my dealer to have the belt tensioner replaced. I requested to speak with the technician after speaking with the service rep. The belt tensioner does not have a spring but a piston. There is Hydraulic fluid and not grease inside and this is what was leaking. On my receipt it stated, " Replaced tensioner as per bulletin PIP 5185". Rattle is now gone. Hope this helps others.
Pro
Joined: Jan 2010
Posts: 629
Likes: 65
From: Freedom PA
I stand corrected from my last post. Today I returned to my dealer to have the belt tensioner replaced. I requested to speak with the technician after speaking with the service rep. The belt tensioner does not have a spring but a piston. There is Hydraulic fluid and not grease inside and this is what was leaking. On my receipt it stated, " Replaced tensioner as per bulletin PIP 5185". Rattle is now gone. Hope this helps others.
Another engineer reinvented a wheel that wasn't broken. 3 years and they'll have all the bugs worked out.
They just have to keep justifying why they're still on the payroll.
Ed
Race Director
Joined: Jun 2000
Posts: 13,733
Likes: 66
From: Hurst, TX USA
Hard to tell if you have the same problem without hearing it. Mine sounds like a sewing machine that varies with rpms. Never really loud and over 2000 rpm other engine noises overpower it. I thought at first it was a fan that was rubbing on something and that may still be a possibility. Perhaps this just the DI working? Or does it sound like one of the other problems in this thread?
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
Hard to tell if you have the same problem without hearing it. Mine sounds like a sewing machine that varies with rpms. Never really loud and over 2000 rpm other engine noises overpower it. I thought at first it was a fan that was rubbing on something and that may still be a possibility. Perhaps this just the DI working? Or does it sound like one of the other problems in this thread?
Melting Slicks
Joined: Jan 2004
Posts: 3,012
Likes: 15
From: Jensen Beach FL
I would not count on it. GM has a habit of not fixing issues until the next generation i.e. C8. Same issues remained for the C5 for the entire 7 years of production. Some of the C5 issues still exist today in not only the C7 but other GM cars like the infamous "Rocking Seat" issue. I had a 1997 Cadillac Seville had that issue as well. Then there is the leaky rear axle seal in C5's which has popped up again in the C7. I am guessing with low production cars like the Corvette GM doesn't like to put a lot of effort into correcting issues.
Safety Car
Joined: Feb 2013
Posts: 4,875
Likes: 1,174
I would not count on it. GM has a habit of not fixing issues until the next generation i.e. C8. Same issues remained for the C5 for the entire 7 years of production. Some of the C5 issues still exist today in not only the C7 but other GM cars like the infamous "Rocking Seat" issue. I had a 1997 Cadillac Seville had that issue as well. Then there is the leaky rear axle seal in C5's which has popped up again in the C7. I am guessing with low production cars like the Corvette GM doesn't like to put a lot of effort into correcting issues.
Pro
Joined: Jan 2010
Posts: 629
Likes: 65
From: Freedom PA
Ed
Instructor
Joined: Aug 2006
Posts: 167
Likes: 9
got to see a bad one, not mine. the damping is due to the active fuel management.
its a spring driven piston with hydraulic damping fluid with a seal at one end. kind
of like a very small shock absorber. seal points to the top. pushes on the wheel from
the bottom. I can actually get a decent picture with my camera which i may do later.
its a spring driven piston with hydraulic damping fluid with a seal at one end. kind
of like a very small shock absorber. seal points to the top. pushes on the wheel from
the bottom. I can actually get a decent picture with my camera which i may do later.
SUPPORT AUTISM
Joined: Sep 2009
Posts: 1,954
Likes: 48
From: Suffolk County New York
St. Jude Donor '10, '14
got to see a bad one, not mine. the damping is due to the active fuel management.
its a spring driven piston with hydraulic damping fluid with a seal at one end. kind
of like a very small shock absorber. seal points to the top. pushes on the wheel from
the bottom. I can actually get a decent picture with my camera which i may do later.
its a spring driven piston with hydraulic damping fluid with a seal at one end. kind
of like a very small shock absorber. seal points to the top. pushes on the wheel from
the bottom. I can actually get a decent picture with my camera which i may do later.