Wesens

took it to the dealer today with the engine rattling at 700 rpms. quits rattling at 800. Dealer does not know what it is and has opened a case with GM. the Z51 2015 has 3000 miles on it. they said they want engineers to weigh in before getting into the engine. Now I'm concerned. when I asked what it could be they mentioned an engine pump? anyone have a clue? not what I expected from a $74K car.

Wesens

dealer really has no idea. they've ruled out torque tube (although i don't know why) and fuel pump. they are changing the oil pump on Monday and they "hope" that is the problem. I'm not hopeful. when do I get GM involved? this car has 3000 miles on it and they seem to be befuddled.

6104696

Not enough info. Is it an auto? Could be flex plate. could be high pressure fuel pump. Could be torque tube; why did they rule it out?

Could be any number of things.

Wesens

Yes, it's a stock 2015 Z51 with an automatic. They didn't say why they ruled out the TT, just stated they didn't think it was that. Bottom line, they don't know what it is and want to try the less invasive measures before taking the engine down. Said they dropped the pan and didn't see any issues so they are changing out the oil pump, before pulling the heads.

C7&7

What does it sound like? You have a video or sound clip? My money is on the high pressure fuel pump.

Wesens

I don't have any recordings of the sound it makes at idle. Sounds a little like a coffee can with BBs in it being shaken rapidly. Goes away the second RPMs are increased. From everything I've read on the forums, I wouldn't bet against the fuel pump being the issue either.

Millerrock

I will say this, these days any problem the tech needs to call tech line and most people on the other end have never touched a car in there life!!!!!! The tech calls, they look and see if the issue fits a concern on there computer then tell the tech what to replace or do, if that doesn't fix it they throw another dart until it goes to level 2, then they send a field tech out which again many have never been a tech before and they throw more darts!! I go threw this everyday, it's very said what the industry has gone to and what the customer has to put up with cause the manufacture doesn't want to pay for anything anymore once it leaves there plant!!

Wesens

That sounds about right. The car has now been there for 7 business days and nobody knows what the problem is. Sad comment on the state of car repair business today. Maybe I picked the wrong shop to do this work.

C7&7

Does it sound like this?



or this:

Wesens

hard to tell through the laptop crappy speakers, but no I don't think it sounds like either of the files you sent. But thanks for sending them.

KLdy

My car shakes, and vibrates at idle is that what you meant?

Couldnt really show you a video, will try soon.

But as soon as you start moving the vibration is gone.

I searched it was actually design like this because they said

Corvette owners like rough idle....

Wesens

It doesn't really shake. I would describe it as a vibration type of noise emanating from the engine. Goes away once RPMs go up. The service department guys called me yesterday and told me the original noise I complained about has been fixed. They replaced the oil pump and the oil pan. (How could a freaking oil pan be the cause of any noise?) Now that the noise it was making is gone, they said a low "chirping" sound has become noticeable. They said there is a service bulletin out on that "chirping" sound and they know what's causing it. So now they are going to replace the fly wheel. I should get the car back today and it should be noise free. This is the first time I've heard about noise coming from the flywheel, unless the tech mispoke and they are really going to replace the flex plate. Many on this forum have said the flex plate is a possible cause of the vibration/noise. I will let everyone know exactly what they replaced once I talk to the service manager later today.

Millerrock

Please let us know, you would be surprised what can make a noise these days, sometimes it's just replacing bolts to a different length to get rid of some issues, but the flex plate sounds to be the right fix. Not to stand behind the dealer but the public always knows first about an issue before the techs or the tech line. Should deff be the other way around so when the car comes in we can fix it the first time cause who wants to leave there vette at a dealer, but I will say this, I am a very **** tech so when a car is down and it's a clean well taken care of car, I always pull that customer inside till the car leaves, it's a shame the young generation doesn't care and it makes my blood boil.

Wesens

Yep, I hear you on the lack of responsibility. I am getting awful communication from this chevy dealer's service people. They've had the car for 2 weeks. They don't seem to have parts on hand to fix all the problems and I have to constantly call for status. they told me the car would be ready "next day" for the last 3 days but when I call its always "the part isn't here, so tomorrow". Theyve bungled this whole thing as far as scheduling the work and parts ordering. Bottom line: They've fixed the noise issues. Replaced the oil pump and oil pan. That exposed another noise they traced to the fly wheel. They replace the fly wheel and they tell me all the noise issues in the engine have been mitigated. That's good, but they didn't fix the original issues with the roof creaking and the temperature sensor, which were 2 of the 3 problems I informed them about 2 weeks ago when I brought the car in. So 2 weeks after the fact they tell me they don't have a temp sensor on hand and I will have to wait another day. I told them I'm picking up the car tomorrow by 5 pm. I would definitely like to have my all American sports car back for the 4th of July weekend! I need to get my Vette out of jail!

firehawk44

I was driving my C7 (see Avatar) to a BBQ yesterday when the car suddenly started shaking and I thought it might be bad gas as I was getting nothing from the accelerator. I pulled over and had it towed to the dealer and they tried to start it but it would not start. They said it sounds like the flywheel and it should be a quick fix if that's the case. I have listened to the second video above and that sounds much like what it sounded like before the engine died. Have a little over 13,000 on the 2014 C7 and it is fully covered under warranty so it's just an inconvenience. The fact the engine does not start (there's just massive vibration and a rumbling sound) sort of scares me. I was lucky I was just going to a BBQ. I golf 5 days a week (weather permitting) and it would have been horrible if it had stopped working on the way to the course!

Was it your flywheel too? Mine might have been going some time ago. I drive it in Sport Mode and have loud rumbling noise from the mufflers and it always sounded great. Although an automatic, I drove it in manual mode with the paddles. Because of the holiday weekend, service won't be able to diagnose mine until Tuesday.

C7&7

My video above ended up being the high pressure fuel pump. If it stumbled and died then odds are that's it. Easy fix.

Wesens

The noise was a combination of a couple different things. First the oil pump was found to be making noise at 30 PSI and disappeared when the pressure went up to 40 PSI. So essentially making noise at idle. After they replaced the oil pump another "chirping" sound was detected. There is a known problem with the flex plate. I didn't know that a flex plate is the automatic transmission equivalent of a flywheel in a manual. The service manager explained to me that the earlier C7s had a riveted ring around the plate. One of the rivets was loose and caused the chirping sound. He said they replaced it with a flex plate they put in the 2017 C7s. It doesn't sound like your flex plate would make the engine quit, though. When I asked him if my flex plate would have eventually failed and caused the engine to quit, he said that it wouldn't but would have become noisier and noisier with time. I really don't know. Just what he said, but he sounded pretty knowledgeable. Good luck with your ride! It sucks when the 'Vettes are in the shop! Hope they figure out your issue.

C7&7

Ask the shop to check the fuel trims and check for misfires. That's a sure sign it's the fuel pump.

firehawk44

It turned out to be larger than thought. The engine failed. According to the mechanic and service manager, a loose valve dropped into one of the cylinders causing a major failure. Fortunately under warranty and they are replacing the engine. My old engine is being returned for the techs at GM to check to see exactly why the engine failed. I never drive my Corvette hard or fast and was not going fast (under 40 mph) when the engine failed. I hope to get the car back this week. My experiences with the service manager and dealership have been great so far. Just hate the inconvenience.

Cromagnum

Damn bad luck on that one. That would explain the BBs in a can sound you were getting. Whichever cylinder that happened to was misfiring like a ****. It smoothed out at higher RPM due to firing order. One cylinder missing out of 8 will feel and sound like crap at idle, but will be quieter at higher load.

Hopefully Chevy will make it right with you in a hurry.