Hey just a question before i start digging into things. I just got a z fired up i been fixing up. Its been sitting for a while i know it ran fine before it was parked (minor accident). Fixed the accident damage and now i get the engine running right (o2 sensors and maf were toast). Now it's making a intermittent rattling sound from the front of the motor. I used a stick against the motor to my ear and it doesn't sound like it coming from the guts of the motor. it sounds like it right at the front maybe the timing cover? more to the left side....like by the crank angle sensor area or maybe more down in the front, its really hard to tell where exactly its coming from. its there at idle but its not constant, it stops for half a second then start up again and its like a rattling almost like a loose timing chain kind of sound. it does get louder a bit as u rev it up and then quiets as it hits about 4k and im not revving it that high anymore i just needed to see....

k well just if anyone has any ideas before i crack the case open and take a look what to look for or if its dire i should just scrap the motor and do the v8 swap i planned eventually, lol. by the way my car is a 1990 slicktop NA 5 speed.(made 05/89).
thanks

 

Hey just a question before i start digging into things. I just got a z fired up i been fixing up. Its been sitting for a while i know it ran fine before it was parked (minor accident). Fixed the accident damage and now i get the engine running right (o2 sensors and maf were toast). Now it's making a intermittent rattling sound from the front of the motor. I used a stick against the motor to my ear and it doesn't sound like it coming from the guts of the motor. it sounds like it right at the front maybe the timing cover? more to the left side....like by the crank angle sensor area or maybe more down in the front, its really hard to tell where exactly its coming from.

its there at idle but its not constant, it stops for half a second then start up again and its like a rattling almost like a loose timing chain kind of sound. it does get louder a bit as u rev it up and then quiets as it hits about 4k and im not revving it that high anymore i just needed to see.... my guess is that its something to do with the timing belt, maybe a idler pulley or something?? just seems weird the noise has moments when it goes quiet and sometimes i dont hear it at all for a bit, then it starts again.

k well just if anyone has any ideas before i crack the case open and take a look what to look for or if its dire i should just scrap the motor and do the v8 swap i planned eventually, lol. by the way my car is a 1990 slicktop NA 5 speed.(made 05/89).
thanks

 

Could it be the fan brushing up against something on the left side? Like a coolant hose that's not quite in the right position.

 

How about the Bearings in the Timing Belt Idler, in the Middle of the V..

Mine were falling out with a Rattling Noise.. Hard to locate.. But it was in the Middle of the V .. Drove about 2 Hours till we shut it off and pulled it down.. WHEW.. did not toast the Motor..

Cap

 

Have you tried taking a wooden dowel and pressing against random spots of the motor on one end and up to your ear on the other. Its like a stethoscope (*spelling). Helps pin point knocks, pings, rattles, alot easier than furiously staring at the motor.. Doesn't always work as planned but i've had good luck with it! Even a good solid screw driver will work ok but the wooden dowel is best!