noob needs help diagnosing engine tick

[mhiggi02]

I just bought this e30 yesterday. I hear these M20 engines are "sewing machines" but does this sound "normal" or do I have something I need to address? I'm only beginning to learn to work on this car myself. Thanks.

http://www.youtube.com/watch?v=PkUDcx2UdLQ

[naplesE30]

thats not normal.

[mhiggi02]

any ideas what it is?

thats not normal.

[Cabriolet]

sounds like you need a valve adjustment.

[spdracrm3]

definately not normal

sounds like a rod knock or bad wrist pin ,either way needs serious engine work, ouch

[Ramgoat]

sounds like u need oil

[mhiggi02]

oil is full

sounds like u need oil

[shiftbmw]

Certainly not normal. It's hard to pinpoint exactly what's going on with the video, but check the easy/free things first. I've heard exhaust leaks at the header/head interface sound an aweful lot like that. I'd start there.

In addition, I'd check all the rotating assemblies on the front of your motor. I've heard some obscene knocks out of pulleys, fans, waterpumps, etc. Things hang in the way or rattle loose.

Short of those things, you are looking at something internal. It has a slight hint of bottom end noise, with the likely cause being rod bearings. I can't recall ever seeing a bad wrist pin on an E30(not to say it's not possible, just uncommon).

Lastly, if it is internal to your motor, not only do you need to figure out the source of the noise, but you also need to figure out the cause of failure for the part making it. The point is that you can replace your rod bearings but if poor oil circulation caused them to fail in the first place, without fixing the oil issue you're going to have bad rod bearings again real soon.

[shiftbmw]

Also, some questions that may help you solve your riddle.

Did you buy the car like this? If not, what were you doing when you first heard the noise? Was it sudden onset or did it gradually get louder? Do you have any noise when starting your car and in the first second after startup? A rod bearing will often be VERY chattery right after startup before you build oil pressure(takes about a second).

When were the valves last adjusted and were they adjusted by someone competent? Have you popped your valve cover off and had a look underneath?

[BrownBeanE30]

it might be ur fan is hitting ur radiator or one of ur fuel injector is going out or else it could be ur valves are sticking