chevygirl

iTrader: (69)

I have a 99 Z28 stock with a rattle sound at idle and when you raise the rpms. The oil has 4,000 miles and 6 months and is M1 10W-30. I don't know what the noise is. I haven't noticed anything else wrong. Any ideas.

cws T/A

iTrader: (3)

I used to hear a slight knocking ,rattle sound at cold temp , longtubes and trueduals fixed that.
I was walking by a new chevy truck , the owner started it and I heard the same noise , dont worry about it .

bigbipo

iTrader: (3)

Hey I got one for you guys, Iv recently installed a MONSTER X1 CAM and several oil changes later and prob about 10k miles later.
Last night, I dum my oil to find what looks like eight a roller form my double rollmaster chain or rather more like the dow pin that lines up the cam to cam spocket was stuck to my magnet??!?!??!
Has anyone ever had that DOW pin fall out?????
Besides that theirs no metal and oil psi is still nice and high.. any thoughts?

what the chance its part of my timing chain? or damage it could have done to my freshly rebuild motor?

blkbird

iTrader: (28)

Could be part of the rocker arm, they are known to give out...

bigbipo

iTrader: (3)

no way! this thing is a exact look alike to a dowel pin or worse chain link

ShevrolayZ28

iTrader: (4)

Do you think it's an engine noise? Does it change with engine speed? If it's not an engine noise, I'd check the exhaust, in particular, the rear hangers, which sometimes come loose, also check for loose heat shields. Good luck.

chevygirl

iTrader: (69)

Yes the noise increases with speed. Someone said something about check valves in the air pump. Is that just a normal thing for them to rattle? RAttle is inconsitent also like it does not have a pattern it follows.

ShevrolayZ28

iTrader: (4)

It's not normal for them to rattle or tick, but I've read of some instances where they "tick" on cars with LT's. If you want to rule it out, you could disconnect the AIR pipes and block off the manifold, and see if the noise goes away. (Does your car have LT's? Because I've never read of anyone having this problem with stock manifolds.)

Another thing to check is the accessory belt. To rule this out, you could briefly run the car with the belt removed.

Unfortunately, your noise might be coming from something internal and it could be just about anything. I would do an oil change, hopefully there is no metal stuck to the drain plug .

I would also pull the valve covers and check the rockers, pushrods, valves tips, etc.

How may miles are on the car? And have you given it any savage beatings lately? lol

mrgoodwrench

could also be the a/c compressor clutch mine rattles a lil bit.

chevygirl

iTrader: (69)

I dropped it off at the dealer today and he is going to listen to it. He is the engine guru so hopefully he will know what it is. I notice it mostly when it is warm at idle and when I give it gas you can hear it. I do not drive agressively and I have not driven it hard lately. I use to let it warm up before I drive it but I started just driving slow until it warms up. That is all that is different. I have only had the car since June. It started a tick when I changed the oil to M! 10W-30. I plan on changing the oil next week to Amsoil 5W-40 to see if it helps. I have another vehicle I have been trying to get fixed for 2 years so whenever anything goes wrong with the car I start to freak out because I have trouble getting it fixed. This car is my daily driver and the other is a show truck that I use to drive some. The car has only 52,000 miles on it and it is a Z28. I do have a loss of power that started this week after I got a tank of gas of 93 at Amoco it started this. I have to give it more pedal than I did before. The rattle was already there before this and drove like a race car so I don't think it is related.

jlashley2001ss

iTrader: (5)

lets see...if it were to go away when you rev it up...would that be exhaust related? just trying to eliminate some things.

amatrix74

I had a light rattle only when I let my engine idle and it went away when I would accelerate. it was the torque convertor. hope it helps. peace.

jlashley2001ss

iTrader: (5)

what did you do replace it?

chevygirl

iTrader: (69)

My noise gets louder as you accelerate. It may be piston slap. I don't know.