Grinding noise from Trans? when idle

[Dirk]

Long time lurker... first time poster. Bought my first '09 G8 GT this past November and have put less than 50 miles on her since the roads have been crappy all winter. Needless to say, I'm really itching for Spring to get here.

When idling and in gear (1st or Rev) I get a grinding/rattling noise that increases with acceleration (foot on the brake). If I switch to sport shift and manually put in 2nd or 3rd, the noise goes away which makes me believe its transmission or torque converter related. Yesterday I took her for a quick drive and really opened her up. After returning and being warmed up, I could not reproduce the noise.

Car is stock with the exception of a RotoFab intake & SC 93 Octane Performance RotoFab tune.

Any idea where I should start looking?

[TailG8er]

Check the fluid level.

[Rawyzf]

Any chance that the exhaust was rubbing somewhere, and it just shifted after the drive?

Check the tunnel brace clearance / rear diff area, especially if it has aftermarket exhaust.

[-Ray-]

Long time lurker... first time poster. Bought my first '09 G8 GT this past November and have put less than 50 miles on her since the roads have been crappy all winter. Needless to say, I'm really itching for Spring to get here.

When idling and in gear (1st or Rev) I get a grinding/rattling noise that increases with acceleration (foot on the brake). If I switch to sport shift and manually put in 2nd or 3rd, the noise goes away which makes me believe its transmission or torque converter related. Yesterday I took her for a quick drive and really opened her up. After returning and being warmed up, I could not reproduce the noise.

Car is stock with the exception of a RotoFab intake & SC 93 Octane Performance RotoFab tune.

Any idea where I should start looking?

You buy from Skillmans? Sounds like you need to get under there and take a look. You'll need a floor jack to get it high enough though.

[roman1978]

does it sound like chatter or marbles spinning then its the comverter

[GRRRR8]

Sounds like a heat shield or something like that.

[TailG8er]

Flexplate?

[GM Customer Service]

Long time lurker... first time poster. Bought my first '09 G8 GT this past November and have put less than 50 miles on her since the roads have been crappy all winter. Needless to say, I'm really itching for Spring to get here.

When idling and in gear (1st or Rev) I get a grinding/rattling noise that increases with acceleration (foot on the brake). If I switch to sport shift and manually put in 2nd or 3rd, the noise goes away which makes me believe its transmission or torque converter related. Yesterday I took her for a quick drive and really opened her up. After returning and being warmed up, I could not reproduce the noise.

Car is stock with the exception of a RotoFab intake & SC 93 Octane Performance RotoFab tune.

Any idea where I should start looking?


Would you also like for me to check your VIN? Also include your mileage. I can check to see if there are any applicable warranties.

Brandon
GM Customer Service

[Dirk]

G8Ray - I purchased this from a private party with 25k miles but believe he had some transmission warrant work done at Skillman's back when they were Reeve's (Greenwood) at the 600 mile mark. It's not an alarming sound by any means but definitely not normal. I see your close to my neck of the woods - you ever make it out to O-Reilly raceway on Wednesdays in the Summer?

Fluid level is good but haven't had time to get under and check things out.

Brandon - I'll PM you the VIN. Should have the extended 6yr/100k warranty.

[Dirk]

Oh, wanted to mention also... it's definitely not something rubbing. As soon as I manually shift into 2nd the sound goes away; comes back immediately after shifting back into 1st.

G8Ray - any good references you have as far as GM service dealerships to try in the area?

[-Ray-]

Oh, wanted to mention also... it's definitely not something rubbing. As soon as I manually shift into 2nd the sound goes away; comes back immediately after shifting back into 1st.

G8Ray - any good references you have as far as GM service dealerships to try in the area?

Yes. Call and ask for Jamie Smith, he is the service manager for Skillman GMC Buick in Greenwood at 31 and Stop 11. You can tell him that Ray and Travis sent you. Erik Hess does any service work on our cars.
317 885-2700