2011 Q7 3L TDI won’t crank

[Audi2222]

Hi everyone, really hoping someone can point me in the right direction with the issue i’m facing.

 

I got my 2011 Q7 3L TDI last August, after having it a week issues arose which were caused by the ECU, ECU was replaced by the dealership and the car came back and had been driving perfectly since I got it back in December (took the dealership a while to figure out the issue). Last weekend I parked the car and when i came back about 3 hours later it would not start, “stabilisation programme control” came up on the dash and the glow plug light was flashing. Ignition and lights etc turned on but car did not turn over. Car was towed to the garage and mechanic found an issue with the starter (short circuit internally). When a scan was run no major faults stood out just mainly low voltage faults but we presumed that was due to the battery being dead from the starter. Starter was replaced and battery recharged but the car still won’t turn over. Mechanic tried manually turning the engine using a bar at the flywheel but it won’t budge. Any ideas what this could be? Find it hard to believe the engine could be the issue due to the car working perfectly and no noises etc. I’ll add below some of the fault codes which stood out that weren’t low voltage ones. Really hoping someone can point me in the right direction as I had 3 months warranty on the car which was up 3 days prior to this happening and really hoping it’s not an engine replacement i need.

P065100 - sensor reference to B circuit open
01314 - ECM
03041 - Energy management active 
Stabilisation programme control comes up on dash but nothing from scan?

[cliffcoggin]

1 hour ago, Audi2222 said:

Mechanic tried manually turning the engine using a bar at the flywheel but it won’t budge.

Leaving aside all the electrical faults, the inability to turn the engine over with a lever is especially worrying. Can I assume the mechanic removed the injectors to de-compress the engine?

[Audi2222]

He didnt remove the injectors as it was first believed the issue was with the starter which still was an issue, we have ordered an adapter which goes directly into the crankshaft to try turn it as i had seen on other forms that people were having similar issues, if that’s a no go at turning the engine over I will try that next 

[spartacus 68]

Can’t see it being an engine seized situation if it was parked up. Assume oil level was checked recently?

if mechanic pulls injectors, you’ll need new stretch bolts and sealing washers.

Importantly, you said car was towed? Quattros can’t be towed, well they can if all four wheels on the ground, but not with a dolly or better still flatbed, otherwise you risk damaging the diff.

Battery, if it’s older than 6-7 years, replace it. The Q7 is a big old lump and the electrics are fussy with ECU.

Check fuses as a matter of course. I would also run full VCDS scan and post results.

[Audi2222]

Oil level was checked and was perfectly fine so doesn’t seem to make sense that the engine could be seized, car was literally driving perfectly fine until i parked it and went off and came back 3 hours later to a complete no start. Would you recommend going through with getting the injectors pulled? 
 

With the towing i’m not sure what way exactly the company did it, the car was parked on the top floor of a 5 story car park so i have no idea what way it was done. 

With the battery it was draining straight away prior to changing the starter but once the new starter went in it stayed charged, would you recommend changing this out still? I have the ECU out and it’s gone to get tested so I should have the results of that tomorrow 
 

I can get the scan results this evening and post them here, any ideas as to why the engine won’t crank? It’s mainly the engine not cranking that’s baffling the mechanic, there doesn’t seem to be a clear reason as to why

[Kev-P]

I'd personally start with a new battery. God knows what the old starter motor did to it if it was draining it straight away.

[Audi2222]

Would the battery make any difference to the engine not cranking even when mechanic try’s to turn it manually? 

[Kev-P]

I would say so, there's nothing to suggest the engine is seized. Your mechanic is trying to rotate the engine with the injectors still in, it could simply be compression that's stopping it from turning. These V6 engines are a big lump.

[cliffcoggin]

You may be right Kev, but I am not convinced. I would expect any compression in the engine to have leaked away over a few hours, leaving one able to at least turn it a little with a lever on the flywheel.

Richard's mention of possible differential damage, which is not something I was aware of as a possibility, should be investigated first in my view because of the likely cost involved of its repair. No point in buying a £200 battery if the diff needs several thousands spent on it.

[Audi2222]

Spoke with an audi specialist today and he suggested the timing chain may have slipped and locked the engine, he’s going to take a look in another 2 weeks, i have ordered the specific VW adapter to turn at the crankshaft in hopes that it may turn over, really at a loss here at the different things it could be

[cliffcoggin]

I can't imagine how the chain could jump a tooth in a stationary engine, but if that has happened the last thing you should do now is to turn the engine over else it could be damaged further.

[spartacus 68]

5th floor of a multi-storey - I feel for Nicole here, but I doubt this is a flatbed. Most multi-stories are height restricted, and this won’t have been an easy recovery as they are usually tight as a gnat’s chuff.

Quattros don’t even like odd tyre depth front and rear as it can overwind the diff. Let’s assume it was a dolly. To be honest the driver should be aware of this if they are in the business of recovering vehicles.

Let’s also assume it’s not damaged as would probably have been short journey to specialist.

If it’s skipped a tooth that wouldn’t explain no start? If it has skipped a tooth, then I would still expect it to turn over, but no start. There are chain tensioners, plus this is an engine out job to fit, plus guides, etc.

I wouldn’t start pulling injectors quite yet.

[Audi2222]

Pretty sure it was  dollys they used, they waited till the car park was quieter that evening, was such a pain of a place to happen to as we were 2 hours from home 😞

 

Any suggestions what to start with to get to the solution of this engine issue, it’s not leaving my mechanics for another 2 weeks and i’m at a last resort with hoping this tool will turn the engine at the crankshaft, that’s not getting delivered till next week. My mechanic himself is at a loss too it’s not seeming to add up what’s causing the engine to not turn over 

[spartacus 68]

I’m trying to work out the history of the car. What’s the mileage? Why was the ECU changed? For the record, replacing an ECU or even repairing it is unusual to say the least.

What’s the service regime like? If it’s been on long service intervals every 18k miles then wear could have happened before you bought it.

Personally speaking, I would opt for a new battery. In the scale of things it’s a couple of hundred pounds. It will need coded in.

Ask the garage for a full VCDS scan to see what’s going on. You’ll need the ECU fitted again before that can commence. I understand the garage’s reluctance to start the car without understanding what’s going on, hence being able to turn over the engine.

[Audi2222]

there’s 267000km on it, bought the car from a garage last august, had it 4 days and the car went into limp mode, we have an obd11 and plugged it in when this happened and it was showing up as the crankshaft sensor, garage let us take the car to audi to investigate and they couldn’t find a fault with the crankshaft sensor. The garage i got it from changed out the sensor but this wasn’t the underlying issue as the car was still in limp mode,  they found an issue with the ECU and got a reconditioned ECU and also done the timing chain prior to this as they weren’t sure if it was an issue and they had the engine out already to replace the crankshaft sensor. the car was returned to me mid december with no issues. Never went into limp mode again and no noises or hard starts or anything up until i parked it nearly 2 weeks ago now and it wouldn’t start. 

Service wise it had just had a full service prior to me buying it but the garage didn’t have the service book so i can’t say what the regime was like prior to me getting it unfortunately.

The ECU is currently out being tested to ensure it’s not that causing any issues so once that’s back in i’ll get the scan rerun next week and get the results off my mechanic, i do remember him saying when he scanned it first when it came in it was throwing up a lot of low voltage faults as well as the stabilisation programme control on the dash.

He had the new starter in and ready to go and the battery all charged up and went to turn on the car and again it wouldn’t crank which left him baffled because the starter had the short circuit internally and that’s when he tried manually turning the engine but again no luck. He hasn’t taken out the injectors  or looked further into it as he’s not sure where he could even start with it and recommended taking it to an audi specialist to see if they could help further with them being more familiar with the car and its engine.