No crank, dead engine?

[b3n4]

Hey all, just looking on any input before I start sourcing a new motor. My 3.0T died suddenly when pulling off the highway, trying to start it resulted in a single click. It's a standard and moves in neutral but didn't want to move while in gear. I let it sit for the week until today when I could have a better look at it. After pulling the spark plugs it started turning over and when everything was put back together it started right up. All the fluid levels are fine and consistent. I made it about 60 feet down the road and it died again. Now it doesn't want to spin with the plugs out its stuck pump starting doesn't work. Starting to look like maybe the crank seized up? Anything else to check?

Thanks

[A4Qwattro]

Do you have a scanner to check for ECU codes? Start with that.

Also what is the status of the fuel system? Is there any chance either of the pumps could have failed? You have a lot of troubleshooting steps to take before jumping to a conclusion that the crank seized. Lucky for you, that is uncommon for this motor.

[b3n4]

It only showed a starter jammed fault nothing further to that. I'll double check the fuel pump is working. Both times the car died instantly, didn't seem to be similar to a fuel cut where it sputters and then dies.

[LowKeyLoki]

It only showed a starter jammed fault nothing further to that. I'll double check the fuel pump is working. Both times the car died instantly, didn't seem to be similar to a fuel cut where it sputters and then dies.

Seems like something to do with the starter locking up the flywheel some how? I'd get under the car and take of the inspection cover for the fly wheel see if any teeth are damaged.

[SwankPeRFection]

Any other issues with it? Losing coolant lately any other wacky driving characteristics? What happened before you pulled off the highway? Were you driving normal or did you do a pull? List your mods.

Motor shouldn’t die out if there was a starter issue to begin with. Engine seized would however result in a code for jammed starter as it won’t crank it.

Your issue is the motor isn’t staying running even as you drive, so it’s going to be (if there no physical lockup) fuel, spark, or intake/exhaust breathability. That means either something’s up with the engine’s ability to take in air or to expel exhaust gasses (ie CATs clogged).

Lastly, there have been instances where a seized motor can blow out the starter motor too, so if you end up having to get another motor, you need to make sure your starter is working if you are having to swap it over before you put it all back together, just so you don’t do the job twice.

[b3n4]

It's a 2012 s4 at 208k km, single pulley and APR stage 2 6mt. I replaced the waterpump, thermostate, and pcv at around 200k. First time it died I was doing a pull off the light turning from the exit ramp. Shifting gears the tac just went to zero. It was able to move with either the clutch in or in neutral. I pushed to the work parking lot and it sat there all week until I had time to look at it. I pulled all the spark plugs from it to see if it would turn over and got the single click and again the starter jammed fault nothing else. I took the battery home gave it a full charge yesterday. We gave the motor a push start with the plugs out and it turned over a few times. This seemed to let the starter run as well. Buttoning everything back together it started up no problem and idled the same as before. I started driving it down the street and it felt fine until again I went to shift gears and it just locked up. Tach went to zero again and nothing would move. Motor doesn't want to spin in either direction now while pushing and pulling it in gear. The flywheel doesn't want to spin with a bar either. I think I'll tow it home and pull the starter out. Most likely I'll just keep going and yank the motor.

[A4Qwattro]

I think you might want to inspect your Catalytic converters for blockage. 208k km and Stage 2 is an important detail to leave out of the first post

[RoseJ22]

Could it be electrical? Did your lights/dash and everything go off when it died? I helped a guy one time who said it just died on him and his groundwire from the battery was broke. He thought it was the engine but I vise-gripped it back together for him when I found the broke wire and got him on his way

[b3n4]

All power stayed on the engine just died. Now it's mechanically locked up so hoping to start having it apart next weekend.

[RoseJ22]

To me I wouldnt think a clogged cat would lock up the engine. I would find it odd too if it locked up then ran again then locked up again without really fixing anything.If you cant turn it over with a pry bar or by dragging it in gear though IDK

[A4Qwattro]

To me I wouldnt think a clogged cat would lock up the engine. I would find it odd too if it locked up then ran again then locked up again without really fixing anything.If you cant turn it over with a pry bar or by dragging it in gear though IDK

I can't wrap my head around the car firing up and idling okay the second time either.

Maybe a stuck open injector?

[SwankPeRFection]

Absolutely no other codes outside of just the jammed starter? Hard to believe. If there truly are no other codes, then I’d pull the tranny and inspect the clutch and flywheel and also the starter head while in there. Maybe something is up mechanically with the flywheel or clutch and essentially what you experienced is a stall out due to some mechanical interference there.

[b3n4]

Just the jammed starter fault, but I got the steering defective/term 15 faults when jacking it up in the parking lot. Charging the battery cleared those faults and the car started. Given how it doesn't want to turn over I don't think there's anything in the immobilizer that could hold it. It's almost as if there's a parking pin in it. I'll update once I'm able to start pulling it all apart.

[SwankPeRFection]

Did you happen to scan it before you pulled the battery, like right after the first time it died on you? That would have been ideal as when you pulled the battery, everything would have cleared and with it, any shred of help in finding out what happened initially.

[b3n4]

I should have the initial scan saved. I'll double check and upload it this evening.

[b3n4]

A bit of a late update here, but I ended up dropping a new motor in the car this past spring. I just finished tearing down the failed motor and it had seized a rod to the crank and spun the bearing. Everything else was fine.