JJC5

That's good news. Also you did not overfill the tank, right? It sounds like you followed directions from a video on how to check the oil level. Keep us notified on what you find out.

Dirty Howie

I'm not expert at all. But I listened to a bunch of online videos trying to see if I had a sticky lifter.

Yours sounds like a bad lifter to me. I hope for your sake I am right. But these other guys know this much better than me.

I believe if when your oil heats up the lifters can not stay pumped up. My car is quieter also when cold.

PS: my French teacher in high school was Tres HOT !!


DH

Mark2009

If you have time and if you have some place (laboratory) that does oil analysis...

Draw a sample of oil from the engine. Send oil off for analysis.

If analysis comes back with high iron, you may have a bad lifter. You will have to remove the cylinder heads to remove and inspect the lifters and the camshaft lobes.

If analysis comes back with high tin/lead, you may have a bad rod or crank bearing. You will have to remove the oil pan to inspect the rod bearings and crankshaft bearings. Actually you can just wiggle the rods on the crankshaft... you'll know if you find two stuck together. This may be too big of a do it yourself job (I don't know if you can get the oil pan off without removing the engine).

Arjian

I had follow this procedure

1.To obtain an accurate engine oil level reading, warm up the engine to at least 175°F (80°C). Cold oil will not give a correct oil level reading. Once the engine is warm, turn off the engine. Checking the oil while the engine is running will result in an incorrect oil level reading. Wait at least five minutes (but not more than 20 minutes) to allow oil to drain and settle in the engine. Remove the level indicator from the external engine oil tank and clean it with a lint-free paper towel or a cloth. Re-insert the level indicator into the external oil tank, pushing it all the way in until it stops.

2.Remove the level indicator from the oil tank and read the level on the cross-hatched area. Oil levels that fall in the cross-hatched area are normal.

I just read on the net that adding some fresh oil can make the carbon deposit rising on the surface and it can clog the lifters.
I will keep you posted for sure, thanks to everyone

Arjian

Dirty howie, what you saying sounds good
Mark200x, sorry but I don't know any laboratory who's doing that !?

Just see that I have to pull the heads off to control those lifters, that's ****.. A lot of works for a simple "control" :/
I had think that they comes out from under the intake manifold like on some other american v8

VictoryRedZ06

Damn! Sounds like something is loose...

Ludedude

At first shot it sounds like a rod bearing to me as well. Another possibility might be a bad idler pulley.

bladex10

Thats a knock, Its very apparent with my headphones on. ESPECIALLY when the RPMs go up.

Arjian

Ludedude, what you are saying is very interesting, because I have noticed yesterday before I record my engine noise video that the one of the pulley was not turning like it should !

And let see this :

Very similar knocking noise..

Arjian

That could be a solution too


I'm pretty sure with those lifters:

Arjian

Can I test my lifters like that ??


And he is saying in the comments below that the noise gets louder and louder as the engine warms up.
That's my case, no noise at dead cold start, and become louder when the engine's warming up.
A rod bearing should make noise all the time !?

Arjian

So I'm on the vette Right now! I had start It and kill all the cylinders one by one by unplegging every spark plus one at the Time and no difference what so ever ! The rod bearings are also not involved.
And once more no noise at cold start with a noise who comes with engines heat and I have notice That It comes more from the passenger side.

What are thinking about folks ? Lifters isn't ?

Arjian

I had pull off the valve cap from the passenger sideagain and find some gold glitter in the oil deposit between the valves ! Here is a picture of it:
http://imageshack.us/photo/my-images/266/img1142re.jpg/

Don't know if it's tin/lead of iron it's really really fine, you can't feel it on the fingers. It's like metallic paint.

JJC5

If the knock gets worse after it warms up, it still can be the rod bearings, main bearings or lifters. Also, the pulley will rotate in sync with knock so it might look like it's the pulley when it's not. That metal debris isn't a good sign. Someone said earlier to cut up your oil filter and inspect it. That's a good idea. If you have knowledge on building engines, I would start tearing yours down before starting it again. To get the oil pan off, you'll need to drop the front cradle so the engine must be supported from above when you do that. Unless you know what you're doing, have a professional do it.

Edit: I just looked at your original post and you said that your Z06 is a 2007 model. Certain '07s have a problem with the rocker arm needle bearings. That could be what's going on here. Inspect both banks of rocker arms.

Arjian

Yes I will inspect that oil filter ! But it means that I have to change the oil ! And you can't completely change it without starting the engine, because of the oil tank ! And I ask me if it's not better to let it like that and bring it to a pro. So I can prove there is a big issue with the engine. I just got the car since 1 month, the guy who sell it to me have to pay for that !!

I just looked under the car for that oil pan removal and it's seems to complicated for me because I have no car lift..

I can pull the heads of, but the oil pan is too difficult without a lift. I was so happy to final get my Z06, I'm so disappointed now

As I said, I had upgraded the rockers with the comp cam trunnion upgrade also the needle bearings are totally involved.

JJC5

That's right, I forgot you did the trunnion upgrade. Also, you don't start the engine to drain the oil tank. There are two drain plugs; one for the oil pan and one for the oil tank. You can remove the oil filter and replace it with another one without changing the oil. You'll just need to add a little over 1 pint of oil to replace what was in the filter and what drained out.
Even if you had a lift, the oil pan removal is a very difficult job.
I hope this works out for you and if this is a major failure, I hope you can at least collect part of the damage from the seller.

erikszr1

im sorry to say, you have a bad rod bearing. its real hard to compare your car to subarus and dodge neons on youtube. but im listening to your video and it definetely sounds like a crank bearing. you cant fix this yourself if it is.

ramairws6

This, it's a rod bearing. I've had plenty of engines not knock when the oil was cold on startup. It will get worse if you keep running it too much and knock all the time

Vette @ 71

Had a similar sound on another car. Suddenly developed and after an oil change and some additive it immediately disappeared...Think something had clogged the oil passages..

erikszr1

50kpa??? i think thats less than 10psi.........thats not good. bad bearing will do this..sorry