[omadab]

Hello, on my way home from a 2 hour drive, me and my friend are jamming to music and my idiot a$$ decides to downshift to fourth at about 120-160 kph. Unfortunately for me, I must have ended up in second gear since the car jerked us forward as if I stood on the brakes (8000 rpm). Right after this, I put the car in neutral (check engine light comes on) and tried to get off the highway but the car was giving 0 power. I pulled over in an incredibly unsafe spot and waited a minute before starting the car. On the third try the car started so we headed home. Very weak power but just enough to get us going. Finally got home (with no check engine light) parked the car and called it a night while i cried in bed XD. Next morning comes around, I buy an OBDII scanner and plug it in. I get the following codes:

P054B , P13B4, P0016, P13B6 (8 faults in total)

Online mostly talks about camshafts and such for these codes. Are the internals completely caca?

The engine starts, sounds normal, I haven't driven it again because I'm too scared haha. It moves around a little oddly but maybe I'm just seeing things.
edit: the start up takes atleast 10 seconds of cranks.

[E92William]

Theres a very good chance your valves floated at such high rpm and didnt close soon enough and one bent a bit from hitting a piston or so or that you stretched the timing chain somewhere. It'd be worthwhile to take it to a reputable bmw mechanic not the dealer though and have him look at it and diagnose it. Hopefully it's good.

Before anything I'd try clearing all the codes and giving it a go.

[omadab]

Originally Posted by E92William

Theres a very good chance your valves floated at such high rpm and didnt close soon enough and one bent a bit from hitting a piston or so or that you stretched the timing chain somewhere. It'd be worthwhile to take it to a reputable bmw mechanic not the dealer though and have him look at it and diagnose it. Hopefully it's good.

Before anything I'd try clearing all the codes and giving it a go.

That's a good idea but if there was reduced power on the drive back, would that be because of a possible limp mode? I feel like it would be because of a damaged internals

[Wolf 335]

First pot hole, now this. What's going on man.

[Joebie]

I did the exact same thing at 77mph (124kph) about a year ago.

Valves hit the pistons (confirmed with borescope), timing jumped (speculating this, never proved it), I didn't have faith in the engine anymore so I just replaced the engine. It sucked but in hindsight honestly wasn't that terrible with a couple friends' help. Cost me about $2200 for a used engine and everything related to it, new gaskets and all that good stuff included.

Luckily I own 2 cars so I just drove my winter beater while the BMW was getting its swap.

Read about my experience here: https://www.e90post.com/forums/showthread.php?t=1567315

Good luck!

You may be able to get by with just resetting the timing, but even doing that requires special tools and knowledge. Probably easier than an engine swap though. The reason I swapped was because even if I got the engine running again, I would never have confidence in it knowing that every exhaust valve had smacked the pistons and that it had hit 9200+rpm.

[iqraceworks]

I'm surprised the transmission will even let you get it into 2nd gear at that speed ...you must have really had to pull on the shifter and force it in.

I've never heard of anyone doing this in my entire life ....and this is the second time I've heard about here on the e90 forums in the last couple of months.....

[Joebie]

Originally Posted by iqraceworks

I'm surprised the transmission will even let you get it into 2nd gear at that speed ...you must have really had to pull on the shifter and force it in.

I've never heard of anyone doing this in my entire life ....and this is the second time I've heard about here on the e90 forums in the last couple of months.....

When I did it it was easy as pie to get into 2nd at 75+mph. I've been driving stick for over 12 years (my entire driving life)... never thought I'd make this type of mistake but here I am.

Oh and its really common. That's why there's a name for it "money shift" because it costs a lot of money.

Usually a money shift goes 1st-2nd-3rd-2nd instead of 6th-2nd but either way, same principle.

[omadab]

Thanks for the input everyone. Looks like my 2020 is gonna be a long one :'(
The BMW gods really don't want me to keep driving this car XD
I also have a beater so I'll probably drive that for a little while.
I had to force it in, but even going into fourth needed a decent amount of force. Things we're happening fast and I guess I was not paying attention. I am 95% sure I went into fourth but considering the RPMs went all the way to 8, it's very likely I went into second.

The car runs and drives (very poorly) so if there is any internal damage, it is probably not so bad to be worth an engine swap.

Originally Posted by Joester

I did the exact same thing at 77mph (124kph) about a year ago.

Valves hit the pistons (confirmed with borescope), timing jumped (speculating this, never proved it), I didn't have faith in the engine anymore so I just replaced the engine. It sucked but in hindsight honestly wasn't that terrible with a couple friends' help. Cost me about $2200 for a used engine and everything related to it, new gaskets and all that good stuff included.

Luckily I own 2 cars so I just drove my winter beater while the BMW was getting its swap.

Read about my experience here: https://www.e90post.com/forums/showthread.php?t=1567315

Good luck!

You may be able to get by with just resetting the timing, but even doing that requires special tools and knowledge. Probably easier than an engine swap though. The reason I swapped was because even if I got the engine running again, I would never have confidence in it knowing that every exhaust valve had smacked the pistons and that it had hit 9200+rpm.

Looks like I'll get the borescope and check my pistons also. I have codes for bank 1 and misfires so most likely the timing is off. If I could get away with replacing the head of the engine, I'll probably do that. I appreciate the input. I am a 21 year old uni student so swapping the engine myself is probably not possible. Worst case scenario I grind for a year or so and save up enough to have a mechanic swap the engine :/

[iqraceworks]

Originally Posted by Joester

When I did it it was easy as pie to get into 2nd at 75+mph. I've been driving stick for over 12 years (my entire driving life)... never thought I'd make this type of mistake but here I am.

Oh and its really common. That's why there's a name for it "money shift" because it costs a lot of money.

Usually a money shift goes 1st-2nd-3rd-2nd instead of 6th-2nd but either way, same principle.

2nd gear is like 4 inches to the left of 6th...how in the hell can someone do that and not notice it feels off?? 🙄

[omadab]

Originally Posted by iqraceworks

2nd gear is like 4 inches to the left of 6th...how in the hell can someone do that and not notice it feels off?? 🙄

Happened quick and Im still certain I went into fourth, the force needed + the angle of the shift knob tells me it was fourth :/

[omadab]

I completed the compression test on all 6 cylinders and they all gave back around 190psi with 5 cranks. So the engine isn't completely ruined. However there is still incredibly reduced power after clearing codes and trying to drive. After clearing there is 2 permanent codes P054B and P13B4.
Next step is to borescope the pistons and see if there's any signs of the pistons hitting the valves.
What do you guys recommend after that? Maybe get the timing fixed?
Thanks

[ragingpanda]

Leakdown test

[omadab]

Originally Posted by ragingpanda

Leakdown test

Interesting. Is that gonna help diagnose the valves being screwed?

[iqraceworks]

Originally Posted by omadab

Interesting. Is that gonna help diagnose the valves being screwed?

Yes....it will tell you if the valves are sealing.

[omadab]

Hey guys I am back.
I looked into the leak down test. The problem that concerns me is that if lets say the timing is off, how would I know that the valves are closed properly?

The borescope came in and we looked in all pistons. They look pretty good. Some are perfectly clean, some have carbon build up. It was pretty tedious but we scratched into the carbon buildup just to make sure it was not damage to the piston. Here are some shots for anyone interested.

[Joebie]

Wow, those are some really clean pistons! Mine had much more carbon buildup making the valve-piston contact very obvious. Hard to tell if yours contacted.

I think a leakdown test and pulling the valve cover to confirm timing is probably the next step.

I've never done it but i think you have to get the flywheel to TDC and then see if the flats on the cams are position vertically.

I would expect the timing to be off, but I've been wrong many times before. Either the chain skips or the crank timing chain pulley spins (the crank timing pulley is held in position purely by friction, so an extreme over-rev like we did here could shift it out of position and throw off your timing.... I think the high power N54 guys actually weld their chain pulley in place to avoid this happening.)

Good luck!

[omadab]

So the valve cover is off. Here are some pictures. The intake camshaft does not have any damage on it really, just normal wear.
I am going to put the first cylinder at top dead center and see if the camshaft qr codes are facing upwards. Is it worth changing the chain right away, if the timing is off? Maybe I can put it back together to check if that was my issue and then replace it a couple months later? There is basically no play with the chain but I don't think that's really a way to check if it's stretched XD.
Next step is to check the exhaust camshaft. However I don't really know what to inspect for on the bearing ledges and so on XD.

[omadab]

Originally Posted by Joester

Wow, those are some really clean pistons! Mine had much more carbon buildup making the valve-piston contact very obvious. Hard to tell if yours contacted.

I think a leakdown test and pulling the valve cover to confirm timing is probably the next step.

I've never done it but i think you have to get the flywheel to TDC and then see if the flats on the cams are position vertically.

I would expect the timing to be off, but I've been wrong many times before. Either the chain skips or the crank timing chain pulley spins (the crank timing pulley is held in position purely by friction, so an extreme over-rev like we did here could shift it out of position and throw off your timing.... I think the high power N54 guys actually weld their chain pulley in place to avoid this happening.)

Good luck!

Thanks for your two cents! Do you know of any other ways to check the condition of the valves?

[Joebie]

Originally Posted by omadab

Thanks for your two cents! Do you know of any other ways to check the condition of the valves?

leakdown test is really the go-to test to see if your valves are sealing properly.

IM GUESSING that the process to check your timing is to put the flywheel at TDC (there's probably a mark on the flywheel you look at through a peep-hole in the transmission bellhousing)

Then once the flywheel is at TDC on the correct stroke, you check to make sure that the cams are in the correct position, I'm pretty sure there are flats on the cam somewhere that are supposed to be perpendicular to the valve cover deck when the crank is at TDC.

VANOS complicates things, I don't know how the vanos adjustment modules on the front of each camshaft factor into the equation. I'm guessing that the vanos modules are installed and toqued down at the "full retard" position, then oil pressure advances the valve timing from there.

I've never done this on the N52, i'm just taking educated guesses based on timing ive done on other engines so i could very well be wrong.

My best guess is that since your engine still runs and there doesnt look like there is piston-valve contact, your timing probably just shifted a little bit and needs to be reset. Figuring out how or where it slipped is probably impossible so just redoing the entire timing process is probably your best bet. Basically if youve never done it before, to summarize the process in 1 sentence, you just have to position the crank and both cams at the proper position relative to each other, then lock it down in that position with the various bolts that secure the timing chain sprockets.

You could buy a timing chain if you felt like it for peace of mind, I'm not so sure its damaged though. I'm not sure what the factor of safety on a timing chain is, lol. So I'm not sure if theyre easily damaged by a sudden change in engine RPM.

[Joebie]

oh and based on the second picture, it looks like your eccentric shaft sensor has a bit of oil ingress, meaning now's a good time to replace it if you get the engine running. Usually oil in that muli-prong plug coming out of the top of the valve cover means that sensor is bad or very close to failure.

[CTinline-six]

I would check that all the timing marks line up, that will tell you if there is an issue a long with the leak down test. Is the car throwing any codes?

[omadab]

Hey so I put the first cylinder at tdc and it's pretty clear that the timing is off. The barcodes ontop of the camshafts don't lign up with the vanos. I'm gonna have to do the timing first I guess then check if the valves are bent with the leakdown test :/

I'll post pics when I can