m20 ticking...

[16v of E30]

88 325i,

runs good, idles smoothly, just has a loud ticking sound when accellerating.

i had the valves adjusted and such...

whats the common reason for this sound?

[bmwstephen]

is the ticking at certain speeds when accelerating? I think i have the same issue during initial accel. but goes away once I go past 20mph. sounds like its coming from the drivers side

[rThor432]

The injectors make a pretty loud ticking noise. Depends on your definition of "loud". Outside of that, it's pretty hard for me to call it without being there and hearing it. They can be pretty noisy engines with lots of "ticking" noises.

Do you know what spec they adjusted the valves to? While the factory .010" spec should work fine, I've found that adjusting them to a tight* .010" (or even a moderate .009" on my own cars) helps to keep the noise down. I actually think I was running a loose .008" on one of my M20's, but I'm not positive.. Also, the valve adjustment would be skewed if the car was not dead cold when the adjustment was performed. I don't know anything about the shop you went to, so I assume they did everything right. I'm just asking so that you can look a bit deeper into the ticking issue.

*My definition of loose @ given spec- Feeler gauge moves completely freely although there is no free-play between the eccentric adjuster and valve.
Moderate- Some resistance felt when removing/installing feeler gauge.
Tight- Lots of resistance felt when moving the gauge. The clearance is "tight".

[NC325iC]

time bomb? did you look around for any clocks with wires coming out?

but in seriousness could be an exhaust leak

[Leaf]

e30 engines tend to tick, oh well.

[canbedirtye30]

could be a lot of miles and worn eccentrics and or cam...in which case you can never get rid of the tick...ask me how I know....

[george graves]

How do you know? :|

Injectors can make a good amount of noise too.

[Wh33lhop]

Could be a bunch of things, but M20s (and M30s) are just sewing machines in general, even in healthy form.

[bmwstephen]

i still think an m20 in need of a valve adjustment is still a whole hell lot smoother than an m52/m54. those things rattle ike crazy with the vanos and chain issues and not to mention the additional accessories on the engine needed to maintain emissions.

[enigmaticdream]

A m20 with a proper valve adjustment should sound like a sewing machine. If someone says differently, punch them in the face.

[Adrian_Visser]

What oil are you running? 20W50 might help a bit to quiet things down. I've read that worn rocker shafts and rocker bushings can also contribute to more noise.

[llll1l1ll]

N/m. Wrong spec.

[Ceeker]

What oil are you running? 20W50 might help a bit to quiet things down. I've read that worn rocker shafts and rocker bushings can also contribute to more noise.

If the rocker arms are worn and or the shafts then you will get pronounced ticking above and beyond normal and especially under load. Change the shafts and arms and you'll be good to go. Just make sure your cam isn't worn either. In most cases when changing rocker arms you should get the cam reground or replaced to avoid prematurely wearing out the rockers.

[funcrew]

You can hear the ticking on my M20 a block away, even after valve adjustment. I keep constantly revving it to 7K at freeway on-ramps to try to grenade the motor & be forced into a swap, but that has no effect whatever.

[Devil Inc]

My favorite personal quote for when people ask why it sounds the way it does is, "it's supposed to sound like a singer sewing machine".