Scraping sound after valve adjustment.

[crappycoco]

Last week I've adjusted the valves, and the engine is running much smoother now. But I've noticed a noise, like a metallic tapping or scraping .. Only when the engine heats up. When cold in the morning she runs super smooth.

When I drive to work and not even at operating temp. Just the coolant heats up (its about 2mi) I can hear the noise.

It changes frequency with revs, but not pitch or loudness.

I've already double checked the valves, yesterday I've double checked the sparkplugs and they're all properly seated and torqued to spec. The cables are tidy and in order.

I'm kind of in the dark here, any suggestions?

[squidmaster]

what did you adjust to? if it's tapping: welcome to having an e30, but scraping is more concerning.

[crappycoco]

0.010 inch or 0.254mm (stone cold engine)

I'm familiar with tapping =D, but this is not the usual sewing machine kind of takatakatakataka.
Its more like a "zung zung zung" and only when the engine heats up a bit. I've suspected the fan
blades hitting the plastic on the radiator, but that wasn't it.

I probably should mention I'm an idiot. I was turning over the engine while adjusting the valves
and after finishing everything up - I forgot the key on the crank. Needless to say I shat my pants
when I tried to turn on the car.

The key hit the nut of the fan clutch and fell off - stalling the engine. And loosening the crank bolt.
I've tightened it back and fired up the engine. Works fine.

So the only thing im worried about is the above mentioned noise.
I can record a video if that would help diagnose it.

[101]

I'm a bit unclear about what hit what ...

My recommendation would be:

Remove the timing covers and make sure that the timing belt has not jumped time after the engine came to a halt. How recently has the timing belt been replaced? A sudden shock like that can weaken the timing belt. Consider replacing the belt if only for cheap insurance.

If the fan clutch / water pump took a direct hit with that much force I would replace both of those. No questions asked.

Good luck!

[crappycoco]

The key hit the nut (that one that faces the engine) of the fan clutch. That's it. Engine runs smooth, no idle problems or any other obvious signs the belt has jumped. Was replaced cca 20k mi ago.

[dnguyen1963]

What kind of oil do you put in your engine? Anything less than 15W40 will make a lot of metal on metal noise.

[crappycoco]

Just did oil 400mi ago. Oil is 15W50 Mobil 1.

Video of the noise:

[crappycoco]

I've taken off the cover again and adjusted all the valves again. Sounds much better now.
Thanks ya'll for the help =)