Sounds like a tweety noise coming out the exhaust. I believe it is originating in the engine and being magnified through the exhaust.
Could this be a valve train problem?
Maybe a tired cam chain?
I need to pull the valve cover to have a look right?
Please advise if you have had this problem and what the fix is.
Thank You,Randy
I,m sorry about the lack of info.
This is on a 93 240sx I just aquired for my daughter's first car.I dont know any history on the car, as it has had several owners I'm sure.The car drives pretty well for 138k miles on her. I have noticed an erratic idle! Sometimes above 1500, then a blip of the throttle sometimes brings it back down below 1000. My concern is right now is more of eliminating the noise, cause I'm sure it is causing damage somewhere in the engine!
Modified by Lowco at 6:41 AM 10/11/2005
Noise above 2000 RPM
Typically on the 240 chain noise is heard at the front of the engine and does not resonate through the exhaust. Is it possible the noise could be coming from a baffle in the muffler or even a decentagrating cataylist?
Take a good listen around the front of the engien see if you can isolate any noise from that area first.
Take a good listen around the front of the engien see if you can isolate any noise from that area first.
Thats what I did.I first notice the noise from the exhaust and chalked it up to exhaust noise.After driving a few days, I noticed it coming on around 2000k up.I listened to the motor while reving it, and it sounds as though it is originating around the topend of the motor. Revving it above 2000, you can hear the tweety noise. The best way to describe it is, like when a belt is chirping, but it is not a belt. I'm afraid it is in the valve train somewhere. Maybe a loose/worn chain or tensioner?
I pulled the cover off last night and couldnt see anything difinative. Chain seemed tight, tensioners looked to be in place. Did a cold compression test and got 180,175,170,175Tried to run it with the cover off, but oil was flying everywhere off the cam lobes.Tried the screwdriver to the ear trick with NO luck isolating the noise.
Sounds like a mechanical scraping noise, metal to metal, that only is audible over 2k rpm.
I would think if a piston ring is broken I would have gotten a low reading on at least one compression reading.
Tonight I while pull the alternator belt off and see if the noise is still there.
I dont think it is a vacuum leak but will get some carb cleaner and spray around the intake joints and hoses.
I would think if a piston ring is broken I would have gotten a low reading on at least one compression reading.
Tonight I while pull the alternator belt off and see if the noise is still there.
I dont think it is a vacuum leak but will get some carb cleaner and spray around the intake joints and hoses.
Re: (Lowco)
Honestly some times I feel thats what I am doing here. I try stickies telling people to search before they post. Or I repetitivly have to tell someone to do something for testing and they try to bypass it instead of just doing it. Or I make recommendations for things in general and it doesnt seem to be heard. so I fell I am.......Lowco wrote:Why are you beating a dead horse?
Lowco wrote: beating a dead horse?
Sorry for your frustration!And thanks for your help!I took it to a reputable local mechanic to listen to it. He brought out the Dr. stethescope and poked and proded, thinking the same as I, that it was coming from the head or timing cover. Then he noticed the pulleys the power steering belt rides on were all shiny. He sprayed some belt dressing on it and the sound went away!
Go Figure?
He too thought it was a mechanical scraping sound!
Thanks again for your time.Randy
Modified by Lowco at 1:32 PM 10/12/2005
Go Figure?
He too thought it was a mechanical scraping sound!
Thanks again for your time.Randy
Modified by Lowco at 1:32 PM 10/12/2005