Basically it randomly started happening to my friend today in his 91 Eagle Talon TSI AWD. When it's idling it's not too noticeable, but when it's rev'd it's this noise, like you know when you used to put cards in your bike spokes to make that noise, that's the noise it sounds like.

Any ideas?

Is the check engine light on?

Bad lifter tick or rod knock perhaps.

mazda 13b swap?

Could be an exhaust leak...
In the area of the manifold it may tick just like noisy lifters.

Timing belt tensioner.

No kidding... If it only happens at 3000rpm or so, he better park it 'til he fixes it!

after listening to it again, it happens when it's at idle it's just not as noticeable.

Check engine light is not on

His girlfriend said that it made a clank noise then started doing it, the car, he says also is running lean

Oh it will make some noise at idle, and a whole lot at 3000.
You could see the timing belt flapping up & down if you remove the top cover and hold the revs at 3000.

Exhaust leaks before the O2 housing can register lean on the O2 sensor feedback, and you end up actually running a touch rich.

it doesn't sound like it's coming from the exhaust, he failed the e-text the toxins were 6x the legal limit or something, note the car was sitting for about a year before he bought it

That is definetely rod knock the early stages, it will get worse. Time for rebuild or engine swap.

Ouch, he spent 300 on it, then spent a bunch of other money on the new clutch it needed, break lines, caliper, and exhaust leak fixes, now this, that's too bad.

Spun Rod Bearing

Drain the oil into a clean pan and search the pan with a magnet, If you pull out metal debris, Time to rebuild or buy a new engine.

Also try to get the magnet into the oil pan and search around at the bottom the best you can.

Front Balance Shaft Belt busted, that is my bet.

Take the Upper and Lower Timing Belt Covers off and take a boo!!!

Ghislain.

+1 for me!

You could pull the pan off and check the rod side/side play. While you're down there, pull the end caps off and check to see if you have spun a bearing.

I'd do what Ghislain said first. I bet its timing related, I've heard rod knock, what you describe sounds like its a more rapid sound, which I would associate with a timing component rubbing or flapping around.

Rod knock to me sounds like someone knocking on a solid piece of metal with a hammer.

Possibly a flywheel bolt backed out after the clutch was done. I've seen it happen to a member here in the past. Sounded like it could've been rod knock and was hard to pin-point until the tranny came back off.

I think you guys all got it wrong. I still say its the timing belt tensioner.
The classic sound of a card going through bicycle spokes, is exactly what the tensioner arm makes when its bottoming out on the tensioner.
Every heard what rod knock sounds like ? It increses with rpm, and isn't quite fast as the way he is describing it.

Pull the upper t-belt cover off, and watch the belt with the engine on.

How would his car still be running if the timing belt was flapping around?

Its possible to be loose but still go round and round without falling off or skipping but its risky business.

The tensioner is the same part that I was telling/warning you about yesterday.

On second thought, just let it go...
It is a right of passage for every DSMer to pop their timing belt cherry

ya that's why when people are suggesting that, I was like how is possible to still be running, but I guess stranger things have happened

Ain't that the truth. I now know how much it hurts for a woman.

And you usually utter the same cry... "AHHH F***"

It sure does sound like a timing belt issue.

Just pull off the top cover and see how much play you have between the cam pulleys, as well check how much play you have before the exhaust pulley, and after the intake pulley.

If you have more then a couple of millimetres then it's time for a change.

If you want a hand doing it, let me know. I can do a 1g timing belt in like an hour and a half! lol.

I've done way too many of them.

Well I know if the guy brings it up here while Kevin is here at my house, then I know Kevin can rip them apart in no time at all. And also you driving from a kitchener is like 2 hours of driving for and hour of work
Thanks for the offer though!

I wouldn't judge a timing belt's quality by testing deflection between cam gears. You'd be changing timing belts every couple weeks.

Yup, it's normal for the timing belt to have some slack b/w the cam gears sometimes, when the engine is not running though. As soon as you crank it, the tensioner does its job and takes up that little slack.
It has to do with what position the stroke is in, and the intake cam.

Looks like it is a timing belt issue, the hydrolic tensioner I guess died

^^^
Did it take out the engine yet?
Most likely it will if he doesn't fix it.