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Valvetrain noise?

shawn3091

shawn3091

New member
I have a tapping sound coming from the top end in the valvetrain, it is what sounds like a bad lifter or loose rocker arm. The valvetrain is all original nothing in it was replaced when i rebuilt the engine that had 116,000 miles on it except for the 1.9 modded rockers i put in, the cam looked fine when it all went together and the car ran great and was quiet, now that i got about 5,000 miles on it, its making this noise. first thing i did is put a new set of lifters in and it was still there just like before. then i checked over the valve springs for cracks and couldnt find any, but i found one i could just spin around with my hand, so i figured it was weak and put comp 105 springs in along with the right retainers and locks and also new comp push rods. this is where things get strange, it was completely quiet again, i drove it about 15 miles to work sounded good, and on the way home it started again and is now just as loud as it was, and whats weird about it is sometimes as i drive it it goes away for a few miles then comes back, and when its tapping it reads it as knock and pulls about 14 degrees timing out, im lost and have no idea what it could be other than maybe a cam lobe worn even though rollers on original lifters were fine? or i got a new lifter thats defective but i doubt it because the sound is in the same spot. Used a friends scope and put it down near the middle of the v on the drivers side and thats where you can really hear something like the lifter just slapping on the cam. Oil pressure is 70 pounds at 1800 and compression is good and even on all cylinders, and i did change the oil and it doesnt appear to have anything in it. If anyone has any ideas for me or have ever heard of a cam in these being bad, anything would be appreciated.
 


A buddy had a similiar issue when a cam bearing spun. It's not common and what happens is oil is cut off to those lifters and they can't pump up.

How did the oiling look? Any dryness or oddness about it?
 
oil is coming out all the pushrods, doesnt shoot out and make a mess like i would think it would but just kinda runs out a little
 
that's about all it should be. OR rods or regular rods?

tough to think you got another set of bad lifters. Odd about that spring being weak/loose.
 


tore it down and the cam bearings are wore on the bottoms of all of them and the cam has some up and down play in it, guess i should have put new in when i did the rest, im thinking its keeping pressure to some of the lifters down, So now i have new bearings and a xp cam on the way from zzp :)
 


well, i just got the engine back in the car with new cam bearings and my new xp cam and wow same noise in the same spot and just as loud as it was and that is also with the known good lifters put in the back, so im at a loss and going to get a adjustable pushrod and move it around until i get the noise out of it and then get one different length one, I have no idea what else to try to do?
 
Measured and figured out that i have .100 of preload, i was told there should not be over .060 of preload, does this sound like it could be my problem? Thinking of trying 7.000 pushrods instead of the 7.050 ones i have now
 
Sounds to me like you have a valve that has mushroomed and is not the same length as the rest.
take all rockers off and put a straight edge across as many of the tops of the valves as you can and see if the one making the noise is longer than the rest.

that is why the measurement you had is out of specs.
 


yeah you should be able to. Once the rockers are out of the way you can probably just visibly see if the valve stem appears to be slightly higher than the rest of them.

Probably can get away with just only removing the valve cover to check it.
and if you feel you need to remove the spring you can do that with minimal work as well.
 
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