Diesel sound normal for M20?

[BROKINBIMMER]

My M20 sounds like a diesel engine. So far I have adjusted the valves, changed oil with 20/50, changed the exhaust manifold gaskets along with new hardware, and replaced the exhaust from the cat-back. The motor is still very noisy and its driving me nuts.

Suggestions????

[travish325]

Buy a newer car?

[willworkfore30s]

Sounds like you most likely have a perfectly running m20

[Cletonius]

Sounds like you most likely have a perfectly running m20

I dunno man, my car is pretty quiet.

OP: what did you set valves at?

[BROKINBIMMER]

i dunno man, my car is pretty quiet.

Op: What did you set valves at?

.010 with engine cold...

[Cletonius]

.010 with engine cold...

You can go a little tighter if you want, where did you put the feeler gauge? Cam side or valve side?

http://spece30.com/forum/42-engine/36556-valve-adjustment-values#45918

[BROKINBIMMER]

You can go a little tighter if you want, where did you put the feeler gauge? Cam side or valve side?

http://spece30.com/forum/42-engine/3...t-values#45918

Valve side, would you recommend otherwise?

[Cletonius]

Valve side, would you recommend otherwise?

Yes, put the feeler between the cam and rocker. It's possible the end of the valve is cupped, causing inaccurate measurements.

[ZM Blue Devil]

properly running m20 is the most beautiful sound in the world. While there will be "ticking", but more like a smooth sewing machine not a diesel. Maybe you have a 324td?

[BROKINBIMMER]

Yes, put the feeler between the cam and rocker. It's possible the end of the valve is cupped, causing inaccurate measurements.

Well, what is the gap supposed to be between the cam and rocker?

This gap can't be the same as adjusting the gap between the rocker and valve...

[DaButt]

lol I had the same question after I got my valves adjusted. The guy who did them for me noticed the noise, too. so he went back in, re-adjusted all the valves, then tried again. Same noise.

That was over a year ago.

[Cletonius]

Well, what is the gap supposed to be between the cam and rocker?

This gap can't be the same as adjusting the gap between the rocker and valve...

Why can it not be the same?

When you set it at the valve the rocker is in firm contact with the cam, same thing happens if you set it at the cam, the rocker is firmly pressed against the valve.

Science!

[BROKINBIMMER]

Ok, little update. I found a broken stud that secures my exhaust manifold to one of the downpipes....

Would this cause an exhaust leak and make the engine sound like poop?

[nickmcc92]

Yes it would.
My valves are set at .008 on the cam side. My motor isn't too loud once warmed up.

[BROKINBIMMER]

It looks like the stud closest to the cylinder head on the forward manifold is broken. I'm thinking this would be a rather difficult removal. Would finding another manifold with good studs be a better way to fix this compared to trying to remove the broken stud?