S52 engine noise

[jasapp]

So, after finally getting my clutch issue taken care of, I've been enjoying my S52 swap for nearly 5k miles without issue.

Yesterday, I was getting on an on ramp, and ran the engine up to about 7500 before shifting into 3rd. Now I've got a lovely new noise coming from my engine. The noise sounds like it's coming from the lower part of the engine. It's much louder laying on the ground close to the oil pan.

This is out of my league. What is this? Help.

[jasapp]

I dunno why the video isn't showing up. This is the link:

http://www.youtube.com/watch?v=qxvJyxhL3Rk

[samiam3356]

I would follow Jon's advice at Treehouse racing.

[jasapp]

For the record, Jon said:

Yikes. no good. You need to not start the car anymore and pull the oil pan. "engine gone" damage may have already occurred, but there's a slim chance that it's just the timing chain guide rail or the oil pump gear- but don't get your hopes up. Pull the pan and there should be something obvious. Save the oil you drain into a super clean pan so you can look closely at it.

[BMW_TUNER]

My vote is rod bearing and it is slapping away like crazy.

Just a swag.

Do not drive it .

[greyis89]

Second vote on bearing gone. Hope it's not a goner best of luck.

[328ijunkie]

7500's a bit much....

[e30rapidic]

wondering if you stretched or broke a rod bolt there and its barely hanging on...

[jasapp]

It's been awhile since I said anything about this. Mostly because it was depressing. I finally started working on it again. I pulled the oil pan and found all the bearings in good shape, but there were bits of plastic presumably from the timing chain guide.

I wasn't really looking forward to replacing it because it required removal of the bolt on the front of the crankshaft. I managed to remove it, but not quite the way I was hoping. Contrary to what I've read everywhere my bolt was *not* reverse threaded, and I managed to snap the bolt in half by tightening it too much. Doh.

On the positive side of things, I did realize that my engine didn't come with a vibration damper. Maybe that's why I'm eating clutches.

[Adrian_Visser]

Define "didn't come with" what is driving your serp belt on the front of the crank? If you really don't have anything there what is the crank pulley bolted to?

Harmonic vibrations can and will take out rod bearings fast so I would suspect that as the culprit and the 7000 rpm point seems to be when harmonics are the greatest on the s52 crank.

[328ijunkie]

Ive never heard of it being reverse threaded... :dunno

[jasapp]

Two pulleys, but no big black donut with teeth like I see here:



Presumably I need one?

[Adrian_Visser]

Edited original post

[jasapp]

The crank pulley was bolted directly to thing with a flange and six holes that slides on the crankshaft.

[328ijunkie]

there wernt 6 bolts holding it on?