No start, possibly no compression

[Mark8235]

Sorry this is my first post here guys but headed here to see if there is any advice from the wealth of knowledge that will be in here. 
 

Long story short, wife’s 2018 Q3 1.4tsi with 65000 miles on click had been running up until Tuesday morning. She drove it home from work on Monday evening and parked it up, no inkling that there was anything afoot.

Tuesday morning we left house at same time, wife comes to my window and said cars not starting. This particular morning was -4degrees so my initial thought was battery issue. Dropped lid of at school and wife at work then back home to have a look. 
 

Jumped in, ignition on and all that should light up appeared to light up so gave it a burl. When ignition turned all I got was a whirring noise, noise you’d expect to hear if there was a starter motor issue, not engaging with flywheel. It was cranking healthy enough so I then discounted battery issue and focussed on it being a starter motor issue. Gave it the usual customary chap with a crowbar incase it was starter solenoid not working. No change, still just a whirring noise. This next bit should have raised suspicion. When you turn ignition against spring and release once whirring starts, let the key back of the spring, the whirring continues until ignition turned off.

 

I was still convinced this was a starter motor issue so called a mobile mechanic, explained above in my words and he agreed, sounds like a starter issue so he came Thursday with a new starter and changed said starter. Before changing starter he listened to engine and thought starter solenoid issue. 
 

Once starter changed, engine still not starting. Making the same fast whirring noise but mobile mechanic now noted auxiliary belt spinning. Took cambelt cover off and cambelt is still intact and spinning but engine not even attempting to fire. Spark plugs out and smell of fuel, so guess not a fuel issue. No faults showing other than clock spring fault that I know about and is in hand. (New clock spring was fitted Sept 23 and has failed again so waiting to get into Audi so they can start a warranty part repair.) . The thing that worries mechanic is that engine turning over freely, he thinks no compression and also on his diagnostic tool the crankshaft speed sensor is showing no data when engine cranked.

Vehicle last serviced in May this year, cambelt replaced Sept 23. 

No obvious loss of oil or coolant, no symptoms prior to Tuesday morning. Anyone experienced similar previously? Is my/wifes engine goosed or is there a sensor that could cause this issue? 
 

Any help much appreciated folks,

 

thanks in advance, Mark

[cliffcoggin]

Mark.

It certainly sounds like there is no compression. Given that the camshaft is turning, the crankshaft must also be turning. My guess is the belt has jumped a few teeth so that the camshaft is out of phase with the crankshaft. If that is so there is the possibility of damage to the valves so it would be unwise to turn the engine again. I suggest you get the car towed or lifted to a garage for a deeper investigation.

Do you have any form of guarantee on the cambelt?

[Mark8235]

It was a reputable independent Audi workshop that carried out the timing belt change, I think possibly only 12month warranty. I appreciate the reply and when I put it all together your hypothesis of timing issue makes sense. Would pistons v valves not have some kind of tragic noises coming from engine? 
Thanks for your reply 🙏

[cliffcoggin]

19 minutes ago, Mark8235 said:

Would pistons v valves not have some kind of tragic noises coming from engine? 

Perhaps, but never having had it happen to me I don't know.

[Magnet]

Hello Mark,

I’m really sorry to hear of your issue. 
If it were mine, I would attack this from the logical stance of getting the compressions tested as the first task. 
If the belt has slipped (and let’s hope it hasn’t) then carrying out a compression test on each cylinder is not going to cause any more damage than has already been done. 
If the belt hasn’t slipped then carrying out the compression test will give essential information before moving on to other non starting possibilities. 
Perhaps you can keep us up to date on what occurs.

Kind regards,

Gareth. 

[Stevey Y]

4 hours ago, Mark8235 said:

It was a reputable independent Audi workshop that carried out the timing belt change, I think possibly only 12month warranty. I appreciate the reply and when I put it all together your hypothesis of timing issue makes sense. Would pistons v valves not have some kind of tragic noises coming from engine? 
Thanks for your reply 🙏

Hi no noises as the cam lobes are designed to throw the cam followers out to prevent valves from annihilating the pistons I reckon it could well be the crank position sensor.

Steve.

[Mark8235]

Thanks for replies guys. So compression test is key I’m guessing. Crank speed sensor is my glimmer of hope in this !Removed! storm. Been losing sleep over this since last week. I’m not the most mechanically minded, paramedic to trade 😂. I will keep the thread updated as I go, let’s hope I have a positive update soon 🤦‍♂️😂. Thanks again 🙏

[Mark8235]

Update. So no compression, zero across all 4 cylinders. Quick bore scope, cylinders look ok but limited view obviously. Some carbon on inlet valves but they don’t think excessive or to a level they think it would cause zero compression. Fault code showing for low fuel pressure now. The garage it’s at are going to retime the engine and if it’s still the same then they would condemn at that point and recommend uneconomical repair on the engine.

[cliffcoggin]

Well if retiming the cambelt does not give decent compression on all cylinders it's likely the valves are damaged.

A new head will be very expensive, but a secondhand head might be a viable option if you can find somebody to overhaul it.

[Mark8235]

See below and attached for garage update 

Hi Mark, We have checked the timing and it was out, We set it back up but we can feel the top end of the engine is tight, Once we re-set the timing there is still no compression so there is internal engine damage, Its going to need either an engine strip down or a new engine.

Vehicle Inspection PC08544.pdf