Follow Up on Blown Engine...Likely Spun Hub

[blockdoc]

Hey guys,
This is a short follow up on my M4 blown engine. There was a lot of chatter on a previous thread regarding my catastrophic engine failure. I told ya'll I would follow up once we pulled the engine and tore down.
As a refresh, car is/was 2015 DCT M4, HiFlo Pure Turbos, Vargas fix with V1 crank bolt capture and Spline lock. Custom BM3 PJT Tune, E50/Methanol. Running high 600s WHP. Regular acceleration felt slight shudder, got "Powertrain failure", intense smoking with gas/oil smell. Stopped vehicle and found spattered oil on rear of vehicle. Threw a rod through block in two places.

Lots of shit thrown (as usual) about tune. Wanted to follow up with some pictures now that I have them. BTW....BMW quoted me 40K!!!! for engine replacement lolol.

Maybe others can chime in, but looks to me like a spun hub likely caused the catastrophic failure. You can clearly see the pink marks placed by the installer when the crank hub was done. You can also see that the timing chain sprocket was broken off. My suspicion is that the hub spun and caused catastrophic timing failure, detonation, fractured rod, then engine grenade. I do not believe this is tune related.

Any thoughts on the damage? We were hoping to just replace the short block.......

Cheers

[E92inSG]

I’m very sorry to hear that. That engine does not look rebuildable at all.

All the best

[TooHighPSI]

From your list it shows you had the CBC on it? Those pink marks on your crank bolt are likely from when it was torqued, plus 270 degrees, my guess anyways. I've seen the intake vanos bolt snap due to intake cam seizing, but might be a secondary failure in your situation due to the lower end coming apart and beating up the valves on cyl #4? I'd be curious what the bearing surfaces look like on your intake cam if you pull those bearing caps off.

[nickl630]

Pics of the pistons? This doesn't seem like a crank hub failure to me... More of a catastrophic internal failure..

Are the valves bent as well?

[G35POPPEDMYCHERRY]

this engine looks fucked. are those last pics of the crankshaft. yikes

[icegrill]

Something doesn't look right.....

[TopJimmy]

Blocdoc,
Sorry to hear and see your loss. What makes you think it was a hub slip? Was the VTT hub pulled and spline contact area showed damage? You didn't say it was a hard pull, and none of the valves look banged. Just wondering if maybe it was a meth problem instead, or rod failure (previous stress/crack)? Need pix of the rod and piston, even if in pieces.
-TopJimmy

[hC1001]

Sry to hear about the engine failure.

Somethings not right if you had a CBC installed. Can you post a pic of it? The mark wouldnt be able to move to the next hole. Did it tear apart?

You wouldnt be the first to have the spun crank hub with V1 of vargas spline lock and CBC tho... bracer/blackey spun his hub with these items installed. https://f80.bimmerpost.com/forums/sh....php?t=1679594

[MisterF80M3]

Subbed

[Chris@VargasTurboTech]

Wow that carnage is significant! Let us know what you think happened once you have time to diagnose.

Shoot me an email with your info, let's get you a V2 spline lock for your next build.

Chris

[TopJimmy]

I see better now in your hub pic that the pink marks are off a whole a whole bolt. Maybe the hub bolt broke?

[behindthen0thing]

There's no way a broken hub would cause that. That's most likely collateral damage

[ckendri]

Sorry for your loss!

I'm with the guys saying it wasn't a hub slip. The damage makes it look like the problem was elsewhere. The pink marks definitely don't make sense for marking the bolt after torquing if a CBC was used. The CBC locks those two pieces together. Unless the 8 bolts holding on the CBC were sheared or the hex was stripped, then I do not see a way the pink marks can indicate anything other than marking before turning the extra 270 degrees (as already stated). It'll be interesting to see what you are able to determine though.

[mark5092]

WOW, another CA car. All the recent threads for SCH and blown engines are CA cars.

[Twistm4]

Originally Posted by mark5092

WOW, another CA car. All the recent threads for SCH and blown engines are CA cars.

The only pattern with CA cars is California gas is utter garbage. Some of the worst in the world.

OP it's really hard to diagnose based off your pictures. The bolt does look f*cked but it's hard to know what happened first.

The damage to your crankshaft is what is out of line with other CH slippage failures. Something really bad happened in that cylinder.

The reason the marks are off could be because it snapped. Again, my condolences.

[hC1001]

Originally Posted by mark5092

WOW, another CA car. All the recent threads for SCH and blown engines are CA cars.

There was matt720s in NY, the damage looks very similar. Cylinder 4 was fu*ked. He believed his tune or his gas mixture might have caused the issue.

https://f80.bimmerpost.com/forums/sh....php?t=1723037

[Chris@VargasTurboTech]

Yeah, doesn't look like a hub slip, just a fully grenaded engine, which is a bummer. Some detonation signs, if I had to guess would be hot tune or fuel system malfunction (be it wrong octane, injector clogged/etc.). I'm sure you have your hands full, but shoot me an email once you're sorted and we'll make sure you have a V2 for your next build.

Chris

[mark5092]

Originally Posted by Chris@VargasTurboTech

Yeah, doesn't look like a hub slip, just a fully grenaded engine, which is a bummer. Some detonation signs, if I had to guess would be hot tune or fuel system malfunction (be it wrong octane, injector clogged/etc.). I'm sure you have your hands full, but shoot me an email once you're sorted and we'll make sure you have a V2 for your next build.

Chris

Another Paul tune!!

[Lostmfound]

Originally Posted by mark5092

Another Paul tune?!!

I think with the tremendous amount of people running PJT or Cary we are bound to see things like this happen with the ongoing demand. Not too sure the exact amount of people running upgraded turbos tuned by either but im sure the amount of blown engines is negligible (although deep down it never should be) compared to the amount of successful ones. To be honest though I am becoming worried with Paul's minions making revisions to tunes

[blockdoc]

Originally Posted by Chris@VargasTurboTech

Wow that carnage is significant! Let us know what you think happened once you have time to diagnose.

Shoot me an email with your info, let's get you a V2 spline lock for your next build.

Chris

Thanks Chris I appreciate that a ton and will in fact do that. Cheers

[papasmurf_m3]

Jeez. Sorry to see this.

Looks like you bent a rod and it snapped and caused all that damage. Doubttful a spun crank hub will do this kind of damage tbh.

[blockdoc]

Guys. I am up in the mountains in a much needed vacation. I’ll gather up some more pictures when I return home