E30 BMW 318is Engine Noise

[amit_b82]

So, for the past 2-3k miles, the engine has been making a noise. The car is a 1991 BMW 318is. It's hard to describe, but I have posted a video. Here is a short clip:

http://youtu.be/GVn11H97HaE

Any idea what it could be and what it would take to fix it? Noise hasn't affected the way the car drives at all.

[jntar]

Timing clain tensioner and/or rails would be my guess.

[DER E30]

Timing clain tensioner and/or rails would be my guess.

Yup, mine did that 'till I put in a new tensioner...

[amit_b82]

Tensioner was replaced 5k miles ago. If it was the tensioner and/or rails, wouldn't the noise be coming from the front? It is loudest at the top (where I have the camera pointed).

[kwill22]

sounds like your timing is off.

[amit_b82]

If that is the case, is it because the timing chain skipped a tooth at some point? The sprockets seemed fine when I replaced the manifold gasket about 10k miles ago. Also, is this something that can be fixed at this point or is it too late?

[kwill22]

not really. the only way your timing would really mess somthing up is if your valves are hitting your pistons. timing can mess up other things but youd notice somthing was wrong. which they arent because it would sound like a someone put marbles in your cylinders. it is very loud. it sound to me like its off within a couple teeth and the intake vales are opening before the exhaust vales close.
are you having any backfire or noise through your intake?

take your valve cover off and put cylinder 1 at TDC. verify that it matches with the crank timing mark. if youre not sure how to do it take a pic and post it or search here for a pic of how the cams look at TDC.

[amit_b82]

I'll take a look under the valve cover when I get a chance... Hopefully this weekend. Thanks for the suggestion. I'll let u know.

[///M42 sport]

happened to me once, turned out one of the ignition coils was toast.

[jntar]

On that note, did you replace the spark plugs lately? One may have backed out some.

[amit_b82]

Turns out it was my spark plugs. I had replaced them 8-10 months ago, but they had somehow backed out. Thanks a lot for the suggestion. I would've never thought of it.