After Header install Blue's (Fixed)
 

Alright this is pissing me off i have had this problem for 2 days and cannot find what is doing it. My car idles fine no rattles or anything but when I rev it while the rpm's are coming back down there is a rattle in the engine bay. While driving normally when the rpms reach 2k - 2.5k the rattle is there. I do have some exhaust leaks because the pipes are not welded up. This morning i tightened all the header bolts and none where loose so the headers are on there good. Car has no loss in power or anything and in 6th gear I do not hear this rattle at all no matter what speed or rpm. Hust the normal ticking sound of an exhaust leak. I did notice though that around those rpms i do not hear the ticking of the exhaust leak like i should but the rattle instead. I hope I am explaining this good enough. I don't think it is internal to the motor because it doesn't do it at idle nor do I hear any strange noises while WOT. Please help asap I need to know if this is a rod or internal problem or if it is just something with the pipes or something.

How about the heat shield(s)? I had to loosen mine when I did my LTs and forgot to retightened the shield on the drivers side.

sounds like a heat shield on the floor pan to me...

I will have to check that heat shield now that i think about i do remember moving it let me check that i guess it is just the vibrations doing it i will check it on my lunch break and let you know.

Well i checked the heat shield and that is not it. Tight as a snare drum under there. It is like a squeaky knock sound almost like something is hitting together. It only does it in that rpm range and it will do it if i hold a gear to 2.7k then it will make the noise again while the rpms are dropping down to go into the next gear. This is sounding more and more like a damned rocker or something coming loose. I have no lose of power and she still runs hard and strong idles well and everything. Anyone with anymore idea's. :bang:

Does it sounds like some marbles in a can being shaken? Do you know what ping sounds like?

Yes it does almost sound like marbles in a can at that rpm yes. I do know what ping is but I have never heard it before in this car. Like I said just started it up yesterday and boom there is the sound.

Sounds like it's pinging to me. Do a PCM reset and then go drive it for a while. Do you have HPtuners?

Nah don't have hptuners however i did more research on pinging and im not sure if it can be very loud or not. also can pining be rpm specific. because if i am cruising in 6th gear no matter what rpm i am at i do not hear the noise. If i wot i don't hear it either but i do hear it when it is passing through those rpms. I will be checking the plugs tonight and see what am i looking for on the plugs that would tell me if it is pinging also new stock manifold gaskets will be going on instead of the paper ones.

could the headers be hitting the crossmember as the engine rocks side to side? jsut a thought, as some headers are real tight in that area

That's true too about the engine rocking. Yes Ping can be RPM specific.

Have you tried to reset the PCM and relearn the fuel trims yet? You have moved the O2's quite a ways back now and it's trying to run off of Ltrms that were established with manifolds. Reset the pcm and drive it for a while to get your Ltrms accurate. This may help if it is pinging.

are you running 93 octane gas?

Im running good gas and put in some octane booster same problem. I had several guys look at it and it sounds like a rocker arm to them. I came home took all the rockers on the drivers side head out and didn't see anything wrong with them. I didn't see and metal shavings in the oil or anything. Next up I will pull the plug i guess I don't know what else it could be and no the header is not hitting the crossmember of the tranny triple checked that.

Are you running stock rockers? Stock Lifters?

Yep stock valve train. I checked for needle bearings and things and didn't see anything.

If you are still running the AIR system, it could be the check valves. I needed to put restrictors in mine along with new valves to get rid of the noise.

I had that problem. I couldnt figure out forth elife of me what was making the noise, but as soon as I started the car it was there. Turned out the header was very close to the k-member and although it looked fine with the engine shut off, it was close enough that it would hit with the engine running, because of all the vibration of the motor.

I can tell you EXACTLY what it is.... one of your hearder tubes is hitting the K-member. I know this because it happened to me and a few buds of mine. Look under your car on the drivers side. You'll see that one of the header tubes is right next to the K-member. That's the one hitting it. You can do one of two things to correct this.. either put a small dimple in the header tube or go your local muffler shop and have them cutout (notch) the K-member at that point with a torch. It won't hurt the K-member or drivability of the car.

That's the knocking that you hear !! Good luck !!

I will check the header again but I don't think it is the header hitting anything because it doesn't sound like a bang. It is more a squeaking rattle type thing. I am going to be pulling the header off tonight and putting oem gaskets behind there. Also I don't think it is a rod bearing or anything because if I cruise down the hwy at 2200 rpms which is normally where the sound is most apparent it is nice and smooth no rattle or anything if i apply a little gas i get the normal tick tick tick of an exhaust leak. I would think if it makes the rattle from 2000 to 2500 rpms while going through the lower gears then it would rattle like hell cruising down the hwy at those same rpms so I don't think it is anything internal. I am also leaning towards a lifter but I thought they normally make a tick tick tick to not a rattle sound. Also these are the pacesetter headers and I don't think they have that crossmember problem plus I got a poly tranny mount so that should stop it before it hit the crossmember also It didn't do it when I intially installed the headers it happened like 2 days later so go figure on that one :confused: I am stumped I pulled all the rockers and pushrods last night and the pushrods where perfectly straight and the rockers looked fine no problem with the needle bearings or anything. I will be changing oil asap and see if I see anything metal in there but I saw no shavings in the head when i pulled the rockers out. It is not a centralized noise either it is definatly in the back of the drivers side of the motor so there is no mistaking that. I will check the header tonight and change gasket and the plugs look fine to no white burning or fouled look to them.

its def. the k member same thing happened to me once i found out what it was i just ignore it now...except mine does it alot when im backing up