[SCANMAN]

Had the same problem on a 2018 1LT with 2800 miles. Not quite as loud but you could hear it in the cabin up to about 1200 rpm. Dropped the car off at Sullivan Chevrolet, Roseville CA on Tuesday morning. The service rep called me that night and mentioned the check valve problem. No call Wednesday. Thursday they call about 2:00pm and I picked the car up. They said they could not find anything wrong, no codes set and the sound is normal and coming from the vacuum pump. Only service performed was a check tire pressure after three days. It is still making the noise! And there is a small scratch on the right rear fender. I had a lot to say while I was there but they were only willing to give me a line of BS.

[JohnsonJ]

Originally Posted by Arugon

Sure thing, hope this helps someone else later down the road. I towed the car to the dealer because I was afraid of a valve train issue and causing more harm to the internals. In this case it wasn’t necessary.

Good to hear. And definitely this thread will somehow help others with same issue.

[Sambeaux]

I'm glad you posted this. Mine is doing a very similar thing. It through a #2 cylinder Misfire code before I even made it to the dealership. I hope its something as simple as a check valve. I think mine might actually be a lifter issue though given the misfire.
https://youtu.be/t8If9vbiueI

[KirkH]

Mine is doing the same thing. It sounds just like the OP video. I have no check engine light or codes. It has 53,000 miles. It is at the dealership now.

I thought it was the belt tensioner, so I changed that, but the noise was still there.

I asked the tech who took it in, if he thought it was a lifter. He said if it was, its the worst he has ever heard. Now that I have found this thread, I think I have the stuck check valve!

Thanks.

[KirkH]

Mine turned out to be lifters. Service told me there is a national backorder on head gaskets so I am still waiting on my car.

[KirkH]

My car is still at the dealership now almost 3 weeks waiting on the national backorder on head gaskets.

I have asked around and evidently the OEM lifters are failing frequently. Most cam kits are replacing the lifters also.

Since there is a back order on head gaskets, maybe this problem is starting to show up more frequently as cars reach around 50,000 miles?

[KirkH]

Dealer reports that after replacing the lifters, it is making the same noise. I advised them about the check valve problem in this thread.

[KirkH]

Dealer does not believe that it is the check valve. Does not know what the problem is.

The service tech said "Hey, you got new lifters!"

LOL!

[f.d]

Use stethoscope or big screw driver and check out 2 pleases.

1- The fuel line, exactly when the fuel line go to the engine, driver side, here there is fuel check valve , it makes tick.
2- EVAP valve, it’s beside throttle body, BMW cars have tick sound comes from it.

I think in the video up , tick comes from the fuel line, because it’s louder in the driver side

[KirkH]

Originally Posted by f.d

Use stethoscope or big screw driver and check out 2 pleases.

1- The fuel line, exactly when the fuel line go to the engine, driver side, here there is fuel check valve , it makes tick.
2- EVAP valve, it’s beside throttle body, BMW cars have tick sound comes from it.

I think in the video up , tick comes from the fuel line, because it’s louder in the driver side

Car is still at the dealership. Been there since 20 July. District Manager for service was supposed to look at it yesterday. I have not heard anything yet.

[KirkH]

It was the camshaft bearing. Trashed at 52,000 miles and whacked the cam. GM is putting a new engine in now!

[mrgoodbytes]

KirkH, glad to hear they finally found the issue and that it is getting sorted. I can only imagine how hard it must be to be without the car for so long.

Do they have any theory on why the cam bearing failed? If they are like any other engine those bearings are part of the block, but given the load they should outlast the main and rod bearings by far. Maybe it’s just a manufacturing defect in that particular block?

[KirkH]

Originally Posted by mrgoodbytes

KirkH, glad to hear they finally found the issue and that it is getting sorted. I can only imagine how hard it must be to be without the car for so long.

Do they have any theory on why the cam bearing failed? If they are like any other engine those bearings are part of the block, but given the load they should outlast the main and rod bearings by far. Maybe it’s just a manufacturing defect in that particular block?

I haven't spoken to the tech yet, just GM customer service, which has been very good.

This car had zero mods. I was the second owner, but based on the names in the bluetooth, I doubt it was driven hard.

[cbr1100xx]

Originally Posted by KirkH

This car had zero mods. I was the second owner, but based on the names in the bluetooth, I doubt it was driven hard.

What were the names? Greatgreatgrandpa ?