Engine Noise

[QwanSanchez]

OK so I'm getting some noise from my engine that wasn't there when i first bought the car. The car sounds fine from idle and if i dont accelerate hard its fine too, but if i accelerate at about 1/2 wot i hear a metallic tapping noise. I dont get the sound when I'm down shifting only under acceleration. It also happens if i accelerate when I'm in a higher gear going slow say like 35 in 4rd or like 45 in 5th. Any ideas? Dosent really sound like lifter tick because its not constant and it dosent happen when i downshift and the rpms go up. The noise has been there for a little while but got alot louder since i out on the x-pipe

 

[DropTopPony]

If it is a tapping sound similar to a lifter/valve tap it could be a spark plug. Check all your plugs imediately to make sure one or more isn't loose. They will get loose and back themselves out of the head eventually shooting out and stripping your threads. The first sign of this happening is a tapping sound. Give it a look...

 

[QwanSanchez]

just for my info how come it dosent make any noise when i downshift? I'm do for an oil change this weekend so while im doing that i guess i'll check the plugs too.

 

[MeanGrn Gt]

are you sure it isnt pinging/detonation? have you bumped the timing or started running lower octance fuel. It seems by when it happens that it might be "spark knock" aka pinging/detonation

 

[QwanSanchez]

Actually i have run alot of diffrent octans in my car over the last month :-\ . umm everything ran on 87 octane in the begining and then like an idiot ran 2 gallons of CAM 2 race fuel before i went to the track thinking i could boost the overall octane of my tank before i ran.( 2gallon of CAM2 mixed with half tank 87) which of course didnt mix properly and made my car through a check engine light till i used all of the fuel. Now ive decided on just running 93 octane. BUT i was having these noises before i ran all the diffrent octane fuels so i dont think thats the problem. I dont knowif it matters but like i said it got louder when i put on my O/R x-pipe i guess cause no cats to muffle the noise.

 

[scarface]

a loose bolt under the plenum, or on the crossmember?

 

[MeanGrn Gt]

maybe back the timing down and take it for a cruise and see if it stops. if not than just bump the timing back up and if it does fix it than you know the problem atleast.

 

[QwanSanchez]

i dont think its a bolt on the penlum or crossmember member i havnt touched either of those so i dont know they would have gotten loose. As for the timing, i guess ill give that a try after i check the plugs.

 

[QwanSanchez]

screwed around with the car today and found out something interesting. apperantly i only hear the noise when there is a load on the engine, i can rev it all day long in neutral and no noise, so maybe its not the engine after all but something in the tranny/clutch assembley?

 

[scarface]

sounds like detonation to me.

 

[QwanSanchez]

hopefully not, but i have the haynes car manual and they have some suggestion about knocking or pinging under load

 

[scarface]

have you put a timming light on it?

 

[QwanSanchez]

negative ghostrider, gotta borrow one from a friend ill keep everyone updated

 

[QwanSanchez]

OK preliminary diagnosis is spark knock, gonna change the plugs tomorrow and see it that helps.

 

[MeanGrn Gt]

if its spark knock you will pry need to back the timing off a little or run higher octane gas in it