How much noise should the valvetrain make?? Should i get worried?

Hey guys,

Ive just been buttoning stuff up under the hood after an engine rebuild and im still a little bugged by the valvetrain noise.

It runs a Comp cam and hydraulic flat tappet set, with comp roller rockers and stock pushrods.

It clicks/taps as it runs and when you rev up the engine, it clicks faster with it.

I popped the valvecovers and wiggled the rockers up and down to test for play and there wasnt any. I changed the oil and found a little metal(maybe enough to make a penny with.) but nothing serious. I also have 64lbs of pressure at hot idle.

Im maily worried because during break-in, two of the rockers came loose and slipped off the pushrods. it was like that until like 5 minutes later i checked the rockers and discovered this. i resecured them and finished the break in. Ever since then it has been in the back of my mind.

Pretty much, I am trying to figure out how much noise it should make. Currently it makes more noise than im comfortable with...perhaps im just paranoid...

What do you all think??

I would be very concerned about the rockers coming off the push rods. Do you have adjustable rockers? Did the nuts come loose on the rocker studs? Or did they.just fall off?

To check the rocker preloading or to see if they're loose you have to rotate the engine so each valve is fully open and check one at a time or in groups.

It's possible you have one or more collapsed lifters. Some of the metal you found may have found its way into the lifters or oil galleys.

Another possibility is that some of the valve guides are too tight, preventing the valves from closing properly.

In any case, I would find the reason for the noise, should be fairly quiet.

Sometimes exhaust leaks can sound very much like valve train noise.

Have you used a stethoscope to help isolate where the noise is coming from?

I would have thought that a penny's worth of metal shavings would be enough to worry me stupid.

You might be lucky if the lifters are hydraulic.

I would have thought that a penny's worth of metal shavings would be enough to worry me stupid.

You might be lucky if the lifters are hydraulic.

Click to expand...

I agree, metal like that would concern me as well.

A hydraulic valvetrain should not make any noise except maybe at start-up after an oil change or an extended shut-down period. If it does something is not right. If you had a professionally built engine, don't let the rebuilder hustle you on this point.

Mine rattles like a tin can but I have Rhodes lifters. It's actually quiet until the oil warms up some. I love the lifters... hate the noise.

i have hydraulic flat tappet it sounds like a sewing machine as it goes. if you have all the noise off in the cabin you can hear it ticking away. its louder on start up when the engine warms it gets a bit quieter.

i've got like 4-5000 miles on the engine in the last 4 years.

the first oil change i did have one chunk in the pan. it broke off something i figured if it would blow up it would blow up i paid extra for the moron that rebuilt it to dyno it before he gave it to me turn key. every oil change after was fine no flakes in the oil and i went out of my way to check the oil constantly for the signs of engine death that never came.

but every car i've seen with hydraulic tappets sounds like a sewing machine chok, chok,chok, etc...

the quite cars that i have seen converted to roller.... but anyway... i mean flakes in the oil is concerning, and you had the rockers come off that is not good.

did you check to make sure the valve train isn't hitting the valve covers?

i had that happen,, and i had to switch to a very thick valve cover gasket and beat the hell out of the oil deflectors to make room. then when my engine builder had to take responsibility for defective valve stem seals on a new engine he changed them and didn't set the tension on the rockers the same as before so they bashed the valve covers again and he had to tighten them a turn or two to make clearance again.