[Drop the hammer]

So at my first autocross event on weekend, on 4th run I heard a very loud pop under the hood. Pulled off track and checked under hood. Belt fuzz everywhere. But about 20 percent of the belt was still intact and would work on the pully’s. so a partial blow? Anyways, some of the cords must have either hit something or wrapped on main pulley and took out crankcase seal on front of engine. As I now have an engine oil leak. I can’t see where it’s coming from but it’s hitting the main pulley and getting nicely distributed everywhere. It only leaks when running and is very minor at this point, but probably could get worse or if belt fragments get sucked into timing chain, which could alter timing or the fragments could block the oil pan suction intake, then the engine could grenade.
I have an appt at my local tuner shop next week for diagnosis. yes I’ll be putting it on a truck to get there as it’s not worth the risk of more damage.

28,000 kms on it. I won’t take it the dealer as there’s a bunch of mods on it, and I don’t really feel like pushing on warranty (in my world you have to pay to play, and I’m fine with that).
Anyone have any similar experience with this happening?

[Drop the hammer]

Or any n55 guys know if I’m on the right track? Engine can fire right up, and idles fine. Codes that were thrown were lean condition and extreme lean condition. Was running Fabspeed sport cat, eventuri, and bm3 stage 2 on 91. I think the code is unrelated to the tune, belt blowing and oil leak, I think it was caused by lots of wide open to off throttle to on throttle on the track and the eventuri intake. I’ve cleared codes, and retuned back to stock tune at this point. Car booked into shop for Tuesday.

[Drop the hammer]

Leak is very small as well, I did the oil level test and during the test it leaked a 2 inch diameter spot on the ground. Oil still shows full. And leak looks like I haven’t lost much oil at all. Sitting for the last 3 days it hasn’t dripped any oil either.

[boostspoon]

Originally Posted by Drop the hammer

So at my first autocross event on weekend, on 4th run I heard a very loud pop under the hood. Pulled off track and checked under hood. Belt fuzz everywhere. But about 20 percent of the belt was still intact and would work on the pully’s. so a partial blow? Anyways, some of the cords must have either hit something or wrapped on main pulley and took out crankcase seal on front of engine. As I now have an engine oil leak. I can’t see where it’s coming from but it’s hitting the main pulley and getting nicely distributed everywhere. It only leaks when running and is very minor at this point, but probably could get worse or if belt fragments get sucked into timing chain, which could alter timing or the fragments could block the oil pan suction intake, then the engine could grenade.
I have an appt at my local tuner shop next week for diagnosis. yes I’ll be putting it on a truck to get there as it’s not worth the risk of more damage.

28,000 kms on it. I won’t take it the dealer as there’s a bunch of mods on it, and I don’t really feel like pushing on warranty (in my world you have to pay to play, and I’m fine with that).
Anyone have any similar experience with this happening?

Belt fragments can’t get sucked into your timing chain unless it’s blasted through your timing belt cover...likelihood = 0.00% chance.

Fragments blocking the oil pan suction intake? Dont know what part you’re referring to, but if you’re asking if it would get picked up by your oil pump/related components, that’s also nearly a 0.00% chance.

The minor oil leak you have is most likely due to the belt pulling a small oil-related hose from where it was attached.

Should be a simple belt replacement and reattachment/replacement of a hose.

[Drop the hammer]

I really hope so. The crankcase seal is directly behind the crank pulley and wrapping belt cords around it can push the seal into the engine, which can then cause seal to contact the timing chain, that grinds up the the seal into fragments and they get washed into the oil sump and can block the suction. That’s what I was meaning. I agree that Slim to no chance of actual pieces of belt could make it past the seal area unless the seal was completely pushed into engine. Also I suppose it could be dct oil as there’s lines running down there too that could have been hit. Wish I had a lift to look from under and remove pan.

[Drop the hammer]

I’ve got A floor jack and jack stands, so I may have a look this weekend. But it’s an oily mess down there.

[swifty]

Keep us posted on what the shop says. Hope it's nothing serious.

[cookiesowns]

Pictures would be nice. This is the first time i've heard of a belt failure on the M2 N55. Hopefully it's not the crank hub... though very unlikely.

Looking forward to updates.

[David1]

Originally Posted by Drop the hammer

I really hope so. The crankcase seal is directly behind the crank pulley and wrapping belt cords around it can push the seal into the engine, which can then cause seal to contact the timing chain, that grinds up the the seal into fragments and they get washed into the oil sump and can block the suction. That’s what I was meaning. I agree that Slim to no chance of actual pieces of belt could make it past the seal area unless the seal was completely pushed into engine. Also I suppose it could be dct oil as there’s lines running down there too that could have been hit. Wish I had a lift to look from under and remove pan.

The belt making its way into the motor along with pieces of the front seal is not uncommon and is very possible.

[Drop the hammer]

I have a few hours tomorrow to inspect it and get it onto jack stands. I’ll take some pics. The belt looks hilarious as only a thin strip remains intact. Looks like the belt only runs the ac and alternator. Anyone know what the dct oil smells like? Is it similar to the typical red atf fluid?

[cookiesowns]

Originally Posted by Drop the hammer

I have a few hours tomorrow to inspect it and get it onto jack stands. I’ll take some pics. The belt looks hilarious as only a thin strip remains intact. Looks like the belt only runs the ac and alternator. Anyone know what the dct oil smells like? Is it similar to the typical red atf fluid?

I don't believe it's similar to typical red ATF fluid. No idea what it smells like. Pictures, pictures!

[Drop the hammer]

Some pics from top

[Drop the hammer]

I tried to get other photos buts it’s tight for the phone to squeeze in there from the top. Most of the oil seems to have come from the crank pulley and radiated outwards.

[Drop the hammer]

Definitely engine oil

[Drop the hammer]

Dropped the pan off bottom and found the remnants of the rest of the belt and underside is soaked in oil. Few more pics. I think I’ll take her in to dealer as I can’t see where it’s coming from. Fingers crossed that it’s a minor repair.

[ZM2]

Damn, hope it’s an easy fix.

A buddy of mine that races PWC TC in a M235ir had a serpentine belt failure at a recent race.

Anyone else heard of this happening with the N55?

[Drop the hammer]

It’s a big mess with oil film everywhere. I can’t handle anything leaking on my floor. Why I was hesitant to pull the bottom pad.

[cookiesowns]

Jesus christ, that doesn't look fun. Hopefully this is a fluke incident and not anything serious.

If it's leaking oil you definitely have a crank seal issue. Not too bad of a fix as long as the crankhub didn't slip.

[amrazM]

If you can’t find the rest of the belt it’s probably inside the engine, I’d suggest not starting it until you have the front crank seal inspected

[Drop the hammer]

Truck is on its way over to pick it up now. Fingers crossed that it’s just the crankseal and belt to repair. Another autocross event this weekend, hopefully she’s up and running by then!!
New to autocross, but wow what a rush, I’ll be a regular in the future.

[Dan@AutoTalent]

I think you'll be fine! Let us know what happens!

[F87_LCI]

What a mess! Looks sort of like a bird getting sucked into a jet engine...POOF!
Hopefully nothing too major and just looks worse than it is. Interesting to see what the shop says. GL