Spun the car on-track in gear; seems perfect now, but wouldn't restart at first...

[iPhoneEngineer]

Summary/Question:

This weekend I spun my car on the track and wasn't able to go "both feet in". The car did move backwards, in third gear, for a fairly short period of time--fortunately only after bleeding off significant speed. Due to a cloud of dust from going off-track right at the end of the spin, I was abruptly disoriented almost immediately at the moment of reversal, and am not sure how far or fast the car traveled in reverse while in gear.

I cranked the car three separate times without succeeding in starting it, each time for slightly longer than it takes to start the car when cold (the engine was actually quite warm, probably 230º*oil temp). It finally started on the fourth or so attempt to crank. My concern is why it didn't start the first few times.

Could this have been some kind of electronic mechanism cutting fuel, perhaps for safety reasons? What is the physical nature of damage that can occur to the engine due to the car spinning in gear?




Backstory:

Just got back from two full days of driving this weekend at Thunderhill Raceway. I spent about two full hours of on-track time with DSC enabled, particularly because the track was being run in reverse and severely lacks safety runoffs in that direction.

I was trying a new line on Turn #3, which is a quickening radius turn that has significantly off camber and additionally climbs a small hill. If it weren't for the hill, I definitely would not have spun even on that line and with the same inputs; likewise, the negative camber increased particularly steeply towards the edge of the track at that part of corner exit, which is blind until moments before apex. The intent of the new line was to straighten out sooner to feed in power, which I had discovered to be instrumental on previous laps but had to wait too long to apply.

I felt the spin pretty early on and started to counter-steer; completely instinctive. The rear end was very light from the hill, so I avoided the brake totally and just lifted from the quite light throttle I was applying. I also caught the reactive swerve, but not soon enough. I even caught the third, but was out of ideas and simply didn't know what else to try, and was not able to catch the 4th swerve (which was much more abrupt than the others). Fortunately I kept the swerves on-track and was probably down to 30MPH or so by hitting the dirt (really hard to know!)

The engine runs completely fine now; I completed about an hour of additional track time without issues (DSC still off). The car also got a dyno run up to 7,600RPM, and I ran it into the yellow zone at least once per ~2:23 lap.

My GoPro was being loaned to a friend for only that session, and though following, I had been escaping it for the whole session. However, he caught up shortly after the spin and captured the cloud of dust kicked up as well as the skid marks. I'll post this when I can for those curious.

[mfanatic325]

Ouch. Perhaps in the heat of the moment, you forgot to clutch in and/or had the steering wheel locked and/or didn't turn the ignition all the way off before trying to recrank the car?
Just trying to think of all the possible little details that could've been overlooked whilst you were in a disoriented state of mind.

[iPhoneEngineer]

Originally Posted by mfanatic325

Ouch. Perhaps in the heat of the moment, you forgot to clutch in and/or had the steering wheel locked and/or didn't turn the ignition all the way off before trying to recrank the car?
Just trying to think of all the possible little details that could've been overlooked whilst you were in a disoriented state of mind.

Yes, the car was definitely in gear (sorry the post is so long--I tried to make this clear, but it turned into an essay). I thought I was going to save the car, and at the instant I realized it wasn't going to happen, I was in the dirt and completely unprepared for the blinding dust that was sucked in both windows. I literally didn't clutch in until the car was at a complete halt.

It's possible I didn't completely turn off the key until right before the starting attempt that worked. However, I thought the car simply didn't crank if you try to restart after a stall before turning it off completely. It's certainly a misleading user experience for the engine to audibly turn over but not fire spark / fuel if that is the case.

[Finnegan]

First, you're okay, and that's the important thing.

Did you turn the car completely off before trying to start it? I seem to recall mine doing the same thing as yours when I spun it at an AutoX. Had to turn it all the way off before it would start. I'm bit cloudy though, as I was a bit flustered at the time.

Oh, and don't feel to bad about it. I spend last Sat cleaning the dust and weeds out of my car from my first off and spin in turn 6 (CCW direction)--passed someone on the inside and was carrying too much speed. Yup. But it was a good learning experience. Not one off today and a bunch of good runs! On the other hand, I did see a Corvette pass SeanK and I (Open Group, Sean driving, me in the passenger seat) on the inside into 10--while it was going backwards and 360'ing off into the dust and weeds. Corvettes are nice to look at, but not when a few feet away, backwards, at high speeds....

[iPhoneEngineer]

Originally Posted by Finnegan

First, you're okay, and that's the important thing.

Did you turn the car completely off before trying to start it? I seem to recall mine doing the same thing as yours when I spun it at an AutoX. Had to turn it all the way off before it would start. I'm bit cloudy though, as I was a bit flustered at the time.

Oh, and don't feel to bad about it. I spend last Sat cleaning the dust and weeds out of my car from my first off and spin in turn 6 (CCW direction)--passed someone on the inside and was carrying too much speed. Yup. But it was a good learning experience. Not one off today and a bunch of good runs! On the other hand, I did see a Corvette pass SeanK and I (Open Group, Sean driving, me in the passenger seat) on the inside into 10--while it was going backwards and 360'ing off into the dust and weeds. Corvettes are nice to look at, but not when a few feet away, backwards, at high speeds....

Yes, I'm pretty lucky actually, as some of the other tricky turns have dramatically less forgiving runoff areas (e.g. a deep gulch, walls, etc). No cosmetic damage to the car that I noticed either, aside from needing a deep interior detailing.

Definitely relieving to hear about your own experience going off-track there, heh! 6 was extremely tricky in the other direction too, especially CW, where I was usually at 100MPH into the braking zone!

The most severe incident of our weekend was a guy who spun his beautiful 1980 911 going through the turn 15 -> 14 combo. Lost the rear end, tried to save it but ended up crossing the track into a wall. Front fender bent into contact with the tire, likely frame damage to the front (only visible underneath the car). Driver was medically fine, a huge relief--how about the Corvette driver?

[RobertRO]

I suppose you could try a full "reboot".
Disconnect the battery negative lead and leave it like day for an overnight.
Then reconnect and see if there's any change. It may not fix it, but it costs zero to try it.

[iPhoneEngineer]

Originally Posted by RobertRO

I suppose you could try a full "reboot".
Disconnect the battery negative lead and leave it like day for an overnight.
Then reconnect and see if there's any change. It may not fix it, but it costs zero to try it.

Car runs fine now, just trying to figure out why it wouldn't start immediately. It could be as simple as not turning the key off all the way. Does anyone know for sure if the car will turn over, but not fire, if it stalls with the key on and you try to restart? What physical damage can be caused to the engine if the car spins in gear?

[Finnegan]

'Vette driver is fine. Weeds, on the other hand, weren't so lucky. SeanK and I were rather lucky too, although I'll chalk more of it up to Sean's track awareness and experience (he spotted the spin in his side mirror and moved out of the way).

14->15 is really not a corner you want to try and "save". I've seen 2 cars into the wall there (both Porsches--both Caymans). If you're going to go off, point straight off and brake, and if you start to spin both feet in. Anywhere else on the track if you can't bring it back in you'll probably be okay, but there, nope, never ends well.

And if it's any more consolation, another buddy of mine spun 1 into the inside of the track and the weeds as well. He was fine as well. Do the dust and weeds look familiar--they do to me! Per Sean, best to just run it straight off on 1 as well--easier said than done though.

[XMetal]

Originally Posted by iPhoneEngineer

Car runs fine now, just trying to figure out why it wouldn't start immediately. It could be as simple as not turning the key off all the way. Does anyone know for sure if the car will turn over, but not fire, if it stalls with the key on and you try to restart? What physical damage can be caused to the engine if the car spins in gear?

It won't crank if you don't complete turn it off. Simple experiment...just go out and stall your car and try restarting without completely turning off the ignition.

[iPhoneEngineer]

Great, thanks for the info guys . That's probably what it was. I'm super curious why BMW wants the car to do that though--I would imagine it has created dangerous situations for drivers trying to restart a stalled car to get out of traffic!

[mfanatic325]

Yeah the same kind of behavior as when for instance you don't hold the key in start position long enough on a cold start and the engine doesn't actually fire up; forcing you to turn the key all the way back to zero and start all over. Pretty annoying when it happens - albeit almost never. I wonder too what the idea was behind this feature/characteristic. Maybe it's to protect something?

[Kgolf31]

I actually have a problem where if the car is running hot (aka AutoX hot) oil temps and the car is turned off, it takes a couple turns of the key (to ignition, then completely off back to ignition) for the car to start.

It's weird.

[E82tt6]

I stalled the car once shortly after getting it (accidentally put it into 3rd instead of 1st, boy was my face red), and I recall having to turn the ignition completely off before it would start again.

[DBE]

Its normal for a car to take a few cranks to fire after a spin. Happened regularly in my evo. I think its to do with the engine flooding but its nothing to worry about

[ncnmra]

I noticed this behavior in my M Roadster. If it doesn't start on first crank (ie: if you don't hold it long enough), you have to back the key out all the way to start over. It freaked me out the first time, as I find this car takes just a little bit longer of a "hold" in the cranking position of the key than I'm used to with my other cars, so out of habit, I've let go of the key before it had fired up a few times.

In addition, I noticed that in some cases after quickly getting in, and turning the key, the starter doesn't fire instantly. In some cases, there is like a 1/2 second delay. It could be due to the engine priming or something?

[inTgr8r]

Originally Posted by ncnmra

.....

In addition, I noticed that in some cases after quickly getting in, and turning the key, the starter doesn't fire instantly. In some cases, there is like a 1/2 second delay. It could be due to the engine priming or something?

Normal starting its best to let the fuel pump charge up first (position1), then start position.

I just made it part of my procedure to get in;
- turn the key to postion 1;
- then put on my seatbelt (system is then charged ) ,
- then start it.

[iPhoneEngineer]

Very good info, all. I suspect my issue was due to heat soak vaporizing the gas in the fuel rail at the top of the engine.

As for the delay in cranking if you turn the key immediately; my understanding of this was that the key needs a couple seconds to complete the cryptographic authentication handshake with the DME before the starter is unlocked. I don't think the car will even crank before this. It is possible the delay is DME-imposed for the purpose of the fuel pump. The key authentication is plausible because the key's RF chip is activated inductively by an a coil that surrounds the key tumbler, so it needs to be very physically close before the process can start (unlike the remote lock/unlock).

[The HACK]

Have a mechanic take the oil pan off and inspect the oil pump nut.

http://www.realoem.com/bmw/showparts...79&hg=11&fg=30

Should be part number 3. If the nut is still on, have the mechanic either use red loc-tite on it, or safety wire it. I've been told that this nut often loosens up when car is spun and moved backwards while in a forward gear. Now, whether or not this is an old wive's tale, I dunno. But I've seen the result of this nut coming loose on the track and it ain't pretty.

Again, I was told that if I ever spin on track while in a forward gear and didn't have the wherewithal to clutch in...Inspect this nut. Luckily, the last time I spun was back when I was a "B" student and my instructor had the foresight to pull the hand brakes that stalled the engine before we started to go backwards in gear.

[iPhoneEngineer]

Originally Posted by The HACK

Have a mechanic take the oil pan off and inspect the oil pump nut.

Very interesting--thanks for the info, exactly the sort of thing I'm looking for (any precautions that should be taken after a spin while in gear).

Perhaps luckily, the car is going in for Inspection II next week (covered by my extended maintenance plan). Dealer claims my supercharger kit will not cause a cost to be incurred unless more work is created by it, which shouldn't be the case at least for the valve adjustment. I wonder what they would charge to inspect the oil pump nut, or if I should even admit that the car spun/was tracked?

Off topic, but anyone noticed a change after Inspection II valve adjustment?

[pokeybritches]

To echo on what Hack said, I've read in multiple places that spinning the engine backwards causes the oil pump nut to come off on most any BMW engine. I have no first hand experience, but it may be something to research.