Is my S50 seized? Where do I begin to figure this out?

[bimmerboy318]

On track today with student riding along. All was well for first 15min, then no power coming out of corner. Realized maybe a cylinder was missing, maybe a bad coil pack. Limped back to pit lane under power. When I slowed down for the turn into the paddock. Engine stalled during the downshift to 1st. Tried to restart but got nothing, was towed back to pit.

Turning the key it tries to cranks and then stops, dash lights go dim/dead. Battery checked at 11V. Maybe alternator died and I didn’t notice the dummy light?

Got it home, charged with ctek charger. Same deal, will crank but never actually turns over. Did I seize it? Oil level is just a bit full. Oil is clean. Although my last blackstone report had me 6 times more aluminum and iron then normal. A bit of glitter in the drain pan as well.

Where do I start the diagnostics? Remove spark plugs and see if it spins? Drop the underpan and try to turn crank with 22mm wrench?

But if it seized, wouldn’t it have done so while on track at high rpm and not at idle?

[Greenday694]

Did you happen to notice if the oil light came on? I was thinking maybe the oil pump nut came off?

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[Auto Parts Guy]

will crank but never actually turns over.

what do you mean by that? I think you just have a bad battery, and something else coincidental.

[bluptgm3]

At higher rpm there may have been enough oil volume to keep things separated, once at idle, rods or mains may have smeared and seized.

So it cranks and does not fire or it does not crank but starter engages?


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[bimmerboy318]

Starter tries but the crank never rolls over. I can’t see the alternator or oil light because the I lowered the steering wheel. Guess I’m saying the starter seems fine.

Also, oil pump nut was red loctited and safety wired this winter.

[Auto Parts Guy]

battery

[bluptgm3]

battery

+1. Battery, due to bad alternator. Voltage on track dropped too low for E36 electronics.

Check electrolyte level, add distilled water, and charge at low amperage for a couple of days.


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[pbonsalb]

If it rotates it is not seized. Could be as simple as bad battery or alternator. If still an issue after that maybe bad cam or crank sensors or bad engine ground.

[das borgen]

Do you know how to push start a car off the clutch? Or do you have one of those jump packs that can act as a battery for a little bit? kinda like this

My guess is bad battery. Take it out, take it to Autozone (or Advance Auto or O Reilly or whatnot) and ask them to test it. It's free. As bluptgm3 said, your alternator dying is probably the reason your battery is now completely FUBAR

[bimmerboy318]

Well, I don’t think it’s the battery. Charged battery with Ctek and nothing. Then tried a jump pack directly to the jump terminal under the hood, nothing. And by nothing I mean the starter gets juice and I hear it try to move but the crank doesn’t turn.

Next step is remove the accessory belt (in case something there is seized, alternator, idler, or something) and also remove the spark plugs, Then, try to turn it with a wrench on the crank bolt. I did the head gasket before and turned it by hand in this configuration with a ratchet. Wasn’t that hard. Turning by hand also eliminates the starter itself. Hoping it spins and then I’ll have to figure out which accessory is seized up.

If it spins, I’ll put back together and push start to narrow it down to starter. I’m really hoping the alternator bearing seized. Power steering pump I rebuilt over the winter. Idler bearing and tensioner are new over winter. AC deleted.

[Auto Parts Guy]

if the battery has a bad cell, then charging and jumping may not be enough. my second guess is your starter. Still banking on the battery being bad though.

[scooper]

did you fully charge the battery? What reading does the charger give? I think bad battery, bad voltage regulator/alternator.

[bimmerboy318]

So I got good news and bad news...

Good news is the battery and alternator are fine!

Bad news is, #1 cylinder spark plug was stuck and when I forced it out, the tip was missing! Motor turns freely one way then stops, then turn the other way and stops.

Question is, why did this happen? I had the keepers and retainers replaced to the newer ones when I had the head refreshed this past winter. won't know if valve dropped until I pull the head. Stock motor, stock tune, dedicated track car. I did have an ugly blackstone report last oil change that prompted me to get a spare motor to freshen up. But I wasn't expecting catastrophic failure like this.

357D64D0-8B18-4D62-8AFB-CDEDC915AA10 by D S, on Flickr

[pbonsalb]

Could a retainer have failed, causing a valve to drop, get hit and bend? 95 were known to have retainer issues. You would see evidence of this if you pulled the cams and lifters. Do you have a scope to inspect the chamber?

[bimmerboy318]

Could a retainer have failed, causing a valve to drop, get hit and bend? 95 were known to have retainer issues. You would see evidence of this if you pulled the cams and lifters. Do you have a scope to inspect the chamber?

I plan to finish the HPDE season and just share my wife's track car. We both instruct and have registered for 2 more events. Once that's done, I'll be pulling the motor and further dissect it.

I already had the retainers and keepers replaced with "updated" ones just this past winter when the head was refreshed as the gasket rotted way at cylinder 6. I have read a post where someone cracked their retainer in half and did the same thing. The 95 early retainers were "soft" and the keepers/valve would pull through. Either way, I am curious to see how it failed. Hopefully Supertech will solve my problem going forward.

I also read that the rod bearings could have gotten so loose that the piston made contact with the valve. After time, the valve head fatigues and just snaps off.

[nick325xit 5spd]

I plan to finish the HPDE season and just share my wife's track car. We both instruct and have registered for 2 more events. Once that's done, I'll be pulling the motor and further dissect it.

I'd go ahead and pull the valve cover. It's quick and easy.

I already had the retainers and keepers replaced with "updated" ones just this past winter when the head was refreshed as the gasket rotted way at cylinder 6. I have read a post where someone cracked their retainer in half and did the same thing. The 95 early retainers were "soft" and the keepers/valve would pull through. Either way, I am curious to see how it failed. Hopefully Supertech will solve my problem going forward.

See above. You're at the point where pulling the valve cover off is like 5 minutes of work.

I also read that the rod bearings could have gotten so loose that the piston made contact with the valve. After time, the valve head fatigues and just snaps off.

If the rod bearings are that loose, you'll hang a rod out the side of the block.