So I recently installed an RR crank pulley in my car
followed the instructions car drove fine for the first few miles then i did a 3rd gear pull to see how it felt .

It was then I notice a weird sound which sounded like the serpentine belt to me . I was close to home and so i let the car idle and took a look at the crank pulley and it wobbles a little bit at idle .

Now the weird part is the car idles and sounds good but when I drive it and give it a bit of throttle it feels like is on LIMP MODE . I sure hope I didn't damage the engine .

Maybe the key in the crank didnt seat correctly on the pulley ? I dont know what could of went wrong here .

Im going to take it off tomorrow and put the stock one back and hopefully everything is good . What do you guys think ?

I would hope for the price that RR crank pulley isn't defective. Do you have a CEL or any stored codes? Maybe the pulley wobbled and damaged the crank sensor but that's a guess. Pulley isn't going to damage the engine, well unless the woodruff key is somehow damaged.

nope no codes at all . What happens if the Woodruff key is damage ?

You can replace the keyway but don't drive it with a wobbling harmonic balancer, if you damage the crank its game over, there was a batch of bad RR racing harmonics but that was a while ago, take it off and put the standard one back double check the crank and key way, let us know how it goes.

Then if you're lucky it can be replaced, or as stated if the crank is damaged the engine is basically done. But it's not easy to damage a crankshaft.

No, not even close. A damaged keyway can be repaired by any competent machinist. See this post in this thread for a keyway repair after the timing chain sprocket wasn't tightened enough.

https://www.clublexus.com/forums/is-...l#post10770568

Also, IME, the harmonic damper on my IS F did not require any puller to remove. It just slid right off the end of the crank like nothing. I had prepared to pull it and to have to use an installer to put it back on, but this was not the case at all. It is absolutely critical that the crank bolt is tightened to the full factory spec. I bought a special tool specifically for this task, so if you are in the Atlanta area (or want to come here) and are concerned about this, DM me and we can figure out how to make sure your bolt is properly tightened.

How did you torque the crank bolt to 240lb/ft when you installed the new pulley?

Indeed. FWIW, before you remove the bolt, make an easy to read mark from the bolt to the damper with an appropriate Sharpie (silver works well) or equivalent. That way you can at least be sure the bolt is as tight as it was when it was removed by checking the marks and making sure they are aligned. Not perfect, but better than pure guessing.

Do you have more details you can share? I bought one from them a few years back, have yet to install it... Do you know where I can get more info to check if mines was part of the bad batch?

When I got mine the front allen bolts that hold your crank removal puller tool were red threadlocked and snapped when I tried removing them. I had no way of pulling the balancer off the crank.
Then the next one I received the rear bolts didn't have any threadlocker so they backed out and cut a hole in the front timing cover.

The front black allen cap bolts should have no threadlock or blue. The rear short silver allens can have red or blue.

Two important things that should be checked.