Loud Noise after 2500rpm

[W_Static]

ok, my problem is after 2500rpm theres this noise, its hard to explain. it sounds like a dirt bike, but under my hood. the noise is almost nonexistent while idling or under 2500rpm but after that you hear it, and its really noticable after 3000rpm. i thought it might be a loose valve or rod but i checked'em out and theres no play. i also checked the turbo and theres a little shaft play which is common on cars with over 100k im still getting boost, and the cars will get to 6000rpm but at that high rpm its unbearable. my fluids are fine, oil change 40 miles ago, but the noise happened 15 miles ago. anyone know what the problem might be??

 

[W_Static]

alright i read about the phantom knock and it does knock but out of all the posts i read no one says it happens at a certain rpm so it might be at boost. ive been useing only 91 octane since ive had the car. would taking it to a shop and plugging it in to a diagnostics comp tell me whats wrong??

 

[98eclipseRS]

i thought it might be a loose valve or rod but i checked'em out and theres no play.

Uh.....not goign to comment on that statement. It does however sound like you have a really bad exhaust leak from somewhere though.

 

[W_Static]

my bad i meant valve stem, i forgot these dohc cars dont have pushrods. so you think the exhaust manifold might have cracked or blew an exhaust manifold gasket??

 

[W_Static]

hey 98eclipsers do you think if i took the car to you, you can help me find the problem?? the side bar of the message board said ur a vendor so you might have parts if i need them??

 

[98eclipseRS]

my bad i meant valve stem, i forgot these dohc cars dont have pushrods. so you think the exhaust manifold might have cracked or blew an exhaust manifold gasket??

quite possibly, did you happen to run te car hard the night before, or right before you started to here this sound?? is spoolup slower than it used to be? check for areas around the exhaust manifold that have alot of dirt deposits that usually a good way to tell if the exhaust mani is leakig.

 

[98eclipseRS]

hey 98eclipsers do you think if i took the car to you, you can help me find the problem?? the side bar of the message board said ur a vendor so you might have parts if i need them??

oh I would not mind helping you at all, I won't be back in the bay area untill saturday night however. And if you need any parts we can order them for you, pm me and we can hook up this weekend or something.

 

[W_Static]

actually i did run it hard the night before and after i dropped my friends off, as i accelorated away i heard the noise. so ive been taking it easy. ill check the spots you mentioned tonight asap.

 

[W_Static]

what part of the bay r u in?? ill definately be available saturday and sunday anytime will be fine.

 

[W_Static]

and actually spool isnt quite what it used to be, small power loss but noticable.

 

[hellotbone]

Sounds to me like a rod knock tell me as your rev it higher does the noise get faster and louder as well?

 

[98eclipseRS]

Sounds to me like a rod knock tell me as your rev it higher does the noise get faster and louder as well?

rodknock doesn't usually sound like a "dirtbike but under the hood."

W Static I live on the penninsula, right next to san mateo so about 30 min north of you. I am down to meet up on sunday I'll pm you and we can figure it out.

 

[W_Static]

it does get louder as i rev it, i normally notice it after 2500rpm, around 2000 you hear something but the sound isnt rough, its smooth then it gets nasty at 4000

 

[W_Static]

cool sunday will be fine, whats a good time to pm you??

 

[98eclipseRS]

check your pm's bro.

 

[1993TalonTsiAWD]

does the engine shake more than normal sounds like a balence shaft belt broke, or the balence shaft is messed up in some way. As for the dirt bike sound...not sure where your going with that

Derek

 

[W_Static]

the engine isnt shaking badly but just for the fact i have no idea the last time the balanceshaft belt was changed, where exactly is it so i can check it??

 

[98eclipseRS]

behind the bottom timing cover, its kinda a pain to get to.

 

[1993TalonTsiAWD]

correct it's a very big pain. You have to remove all the belts, then the pulleys, then the t-belt cover, than the t-belt, and it's in the lower left side as looking for the drivers side wheel. I forgot you have to jack the engine up to take the motor mount off the side of the engine. Just look at the VFAQ under timing belt removal and install

Derek

 

[W_Static]

wow thats alot of work, heh. does the balance shaft belt have anything to do with timing?? one of my friends with a gst told me that it does but his blew cause he welded the wastegate closed. i dont know why he did that, he doesnt have an external wastegate. nut anyways i question his advice so i was just wondering.

 

[98eclipseRS]

it won't directly effect timming but it is tied in with the timming. It will make the car feel really shaky and if your not lucky will get caught in the timming belt and make that break. It should be pretty obvious if the balance shaft belt broke.