what did BMW do, and how do I do it? valve train noises.

[Tree18is]

MY first bmw was an 87is.. m20 of course but it always had a loud valve train, NO MATTER WHAT! my friend goes and gets an 89.. absolutely silent valve train, now Im back into a 325is and its loud as fuck again....

even my friends cars the early cars are loud, the late cars are quite and thats just how it works, dont tell me other wise I WANT TO KNOW WHY!

its not mileage, its not anything, they did something.

BTW, that car with the silent valve train motor blew shortly after, and my current m20 was silent when I bought it, then blew the head, now im on another head and this one is loud... valves adjusted so many times I wore out the bran new Valve cover gasket.

thanks for listening but hopefully TIA for an answer.

[Adrian_Visser]

some noise is normal. If your valves are adjusted too tight the engine will run like shit when cold and idle like crap. However the oil you are running makes a difference too. 5w30 is just too thin for these engines and it WILL exentuate a loose valvetrain. Unless it's very cold (like 0*F) I wouldn't use it.

15w40 in the winter and 20w50 in the summer is good for an average climate, I run it up here in Canada eh.

Don't forget that you should re-adjust your valves again soon after a head swap. And for the most accurate adjustment it should be done bone cold to the cold spec's.

[Liam]

Good rockers and shafts, good eccentrics (no flat spot) and the perfect adjustment .25mm cold.

After the 1st 50 times you do an m20 valve adjustment you get the hang of it.

[Tree18is]

.25mm right on the money.

we all know what im talking about dont try to ignore it.

[jlevie]

I've heard properly adjusted early M20B25's with quiet valves and late production with noisy valves. It isn't that BMW dis something special to later heads, but rather how much wear there is in the components of the head.

[Liam]

Good rockers and shafts, good eccentrics (no flat spot) and the perfect adjustment .25mm cold.

After the 1st 50 times you do an m20 valve adjustment you get the hang of it.

Just to re-iterate.

[Tree18is]

Just to re-iterate.

im gonna do it again tomorrow then! maybe three times in a row.

[jlevie]

If the cams, eccentrics, rockers, valve stems, or valve guides are worn, there will be valve noise no matter how perfectly the valves are adjusted.

[Spinning Tires]

I've always noticed. A car (no matter what it is) always runs its best right before it blows up

[Liam]

I've always noticed. A car (no matter what it is) always runs its best right before it blows up

That is one of the many "Absolute Laws" that governs all machinery.

[Tree18is]

I guess someone sold me a "REBUILT" head and not a Rebuilt head.

FML

[nando]

I switched to adjusting mine hot - there's a different spec for it in the bentley. it's trickier and I wouldn't do it that way until you get the hang of it, but my valvetrain is much quieter.

[Liam]

I guess someone sold me a "REBUILT" head and not a Rebuilt head.

FML

Well, to truly rebuild a head costs a whole handful of money, case in point,

I am a tech and get parts wholesale. Just the parts for one I did for myself cost a little over $700 not including the cam (top of the line OE stuff... I didn't want to do it twice).

The biggest cause of excess noise I have found is caused by worn rockers, rocker shafts and eccentrics, but I would suppose guides etc could as well.

[Tree18is]

I might swap over eccentrics from the Quiet head and see what happens.