Fastmikefree

Hi guys

my engine sounds normal but when recorded with my phone mic, the LT4 sounds terrible when getting close to the SC, like if ball bearings were about to explode!


Car only has 7500 miles...

Hershey71

Take it to the dealer and have them fix it. The car is still under warranty unless you've cracked the ecu and put a tune in it.

Mr. Gizmo

0JUICED1

I haven't heard of a ton of issues with the LT4 (not like the LSA anyway) but there have been some cases were the supercharger needed to be swapped out. Bring it in to the dealer. If the blower has an issue they should change it even if you are tuned. The only mod they could claim hurt the blower would be a pulley. A tune wouldn't spin it harder or affect the blower in anyway.

Cercone

Bill Dearborn

Mine is doing the same thing.

Bill

Fastmikefree

Thanks guys! Appreciated!

I contacted the dealer and got an appointment for after vacation period in September. He confirmed that SC will be replaced under warranty if problem is confirmed. But after comparing against three other Z06, this one definitely has an issue... probably bearing going bad, I agree.

srqmedic

Sounds a lot like an A/C Compressor rattle I had. It resonated throughout, try turning the A/C off.

Ron'sGS

Just curious, why wait until September instead of getting it fixed immediately?

Fastmikefree

Main reason being is that the car is due for yearly maintenance in September/October period. The dealer being at about 150 miles from home added to the fact I will need to come back by train, I prefer to do it all in once.

Also he did confirm that there is no emergency and worse will happen inside SC without any risk for the engine and that I could easily wait till after vacation period.

Clear as mud? Not too sure with my poor english level...

Ron'sGS

Alright, I had no idea that the nearest dealer to you was 150 miles away but unusual engine sounds isn’t something you want to ignore for a few months. I don’t think I would take that chance not knowing what the problem actually is. I hope you’re able to enjoy your car until then.

Warp Factor

Get that documented and on the record, like in the form of an email.

davepl

I would get it checked but I honestly wouldn't worry too much. Here's a little video of my big old 427 with iron manifolds. In person it's deep and rumbly and powerful sounding.

On the phone almost ALL you can hear are the fuel injectors! So the phones tend to really emphasize sounds in a particular frequency range.

Fastmikefree

Thanks for the advice. Done!

Fastmikefree

Thanks for the video. However, I did record 3 other C7 Z06, same as mine, to validate the test, and mine was noticeably noisier.

Bill Dearborn

I have the same bad bearing sound in my SC. It seems worse when the engine is hot. I talked to the dealership Service Writer about it yesterday. He said they have replaced the SC on several CTS Vs due to a similar rattle.

Bill

Fastmikefree

Thanks Bill, that's a good piece of information.

Phil

djnice

I would be concerned about metal getting in the cylinders.

Fastmikefree

That is a very good point! In case of failure of a bearing, pieces might more likely go there!

djnice

My other car has the LSA and the bearings are pressed in from the rotor side. So when they go it could get metal in the engine. I drove it for a while with them screeching at cold start. They also made noise when it got hot from a hard mountain run. I started to get nervous about it so parked the car and bought a vette. LOL. Eventually took it to the dealer and they wouldn't fix it. Couldn't duplicate noise. Eventually took it to second dealer and they had no problem getting a new SC installed. I assume the bearings could get loose and let the rotors make contact for another source of metal bits.