Lubed

Your engine is port injection, the intake valves remain clean by the fuel wash from the injectors. One less job for you.

It pays to double check TDC on No1 cylinder using a screw driver down the injector hole. Are the three lines on the cam sprockets facing each other? Its normal for an engine that's been standing for a long time to have low compression,  compression soon ramps up again after the engine has run for a short period if all engine components are damage free.

Good work.....broken the N46 Voodoo. Even little 4 bangers can be rewarding to fix and bring back from the edge.

Check that you have power and earth at the high stop plug connection, if that's all good then it must be a light fault.

6 hours ago, Palazzo said:

Thinking of changing a car, maybe to a 1 or 3 series diesel. 
But, it will only do short trips, like 2km each way.

Plan is that it gets a scheduled motorway or longer run every two weeks.

Am I asking for trouble? 

Short trips of only a couple kms is torture for any ICE, condensation never has a chance to evaporate and the oil gets contaminated very quickly with fuel, moisture etc.

"MAKE THE N42 GREAT AGAIN" you have my vote. Making these little 4 pots sweet again is not as hard as some make it out to be.

Once oil/coolant leaks, chains/guides, valvetronic motor, stem seals have been been sorted it will be a sweet little engine again for another 100000 + kms. These engines have their flaws yes, but once looked after are underrated.

No, there is a specific service function that needs to be carried out with a diagnostic tester.

Did you teach in the valvetronic end stops after replacing the valvetronic motor ?

The N43 does not have valvetronic, so one less system to fail, that's a positive

1 hour ago, M3AN said:

Oft, that sucks but glad you've identified the culprit, hopefully you can find a cheap-enough replacement. I'm frequently disappointed when related DIY's don't mention re-centring the clockspring, it's both easy and essential.

Despite what others may think the dealership failed you (and themselves) here, they should have insisted that their duty of care couldn't let you drive away in an unwarrantable (read: unroadworthy) car because of a SRS fault. That they'd just completed work on related parts draws them awfully close to legal jeopardy on two fronts; professional liability and consumer rights. Not a space I'd be comfortable playing with my reputation in, and shame on anyone who thinks otherwise. How they didn't diagnose this as a routine part of the work they were completing is mind-boggling (to me).

If you find a new clockspring and need the codes reset (they probably won't clear automatically) feel free to hit me up, can do. 👍

Edit: just in case the pedants come out - I am assuming you have a persistent, or permanently extinguished, SRS light here, before, during, and after your visit to the shop. I can't imagine why you'd be concerned about failing a WoF otherwise, they don't pull codes for a warrant.

Reading back, the Dealership offered to diagnose the issue on the day. That offer was turned down by the owner of the car due to other commitments. What do you propose? the dealership doesn't give the keys back like you would a drunk at a party?  

That's a big accusation, every story has two sides. What's yours?

I would hazard a guess that rings don't fail overnight. Sometimes on engine shutdown the crank can spin backwards a few degrees due to a piston not quite reaching tdc on the compressor stroke. The compression then pushes the engine backwards, if the timing chain is worn then the chain jumps a couple of teeth.

I'm struggling to understand how a engine running perfectly at shut down one night, then come the following  morning the piston rings have failed causing major compression loss and the engine not to fire. Is it worth getting a second opinion from a different workshop or doing a little more investigation yourself? It does not seem like the root cause of your problem has been identified.

A competent mechanic should be able to have the rocker cover off and check the cam timing in 2hrs. With the N47 having a track record of chain issues, it would be high on my list of things to check.

Has the camshaft timing been checked?

Are your injectors activating while cranking? The DDE will not pulse injectors until a specific fuel rail pressure is reached and you  mentioned  a fuel leak in an earlier post. Is it possible you have a air in the fuel system preventing the target pressure being achieved? 

Have you had any oil pressure issues? The vacuum pump and the oil pump are a combined unit and there are rare reported cases of the pump drive failing, maybe worth inspecting.

5 minutes ago, E30 325i Rag-Top said:

Removal of any “emissions system” covers it I believe.

I have had a read through the VIRM but cant see that text, maybe I'm half blind. Where  is that info?

There appears to be no mention of Adblue or SCR systems in the VIRM for WOF. Deleting cats or DPF's is a failure though.

2 hours ago, Jacko said:

Yeah seems to be the biggest issue with it, my 130 lives inside and only comes out when the sun shines now, so shouldn't really be too much of a problem. 

I'm surprised how controversial deleting the cowl is, peoples reviews are all over the place as well - Water drips on engine cover/water doesnt drip on engine cover/makes a huge difference to cabin noise/makes no difference to cabin noise.... One thing is for certain is it weighs a ton and gets in the way for maintenance.

One way to find out  Worst case Ill put it back in. 

Next thing you know your  cars suffering anorexia and fat shaming problems, throwing away your wiper/washer system saving a few kgs and driving around with only 10L of petrol on board.

On 9/24/2021 at 3:04 PM, Jacko said:

Just ordered this setup, fingers crossed it fits E87. Ditch the heavy ass cowl panel without having the engine loom dangling over rocker cover.

https://www.turnermotorsport.com/p-1809115-turner-e9x-cowl-delete-kit/

Something to consider when doing the cowl delete. The cowl panel serves the purpose of diverting the water that runs off the windscreen to the corners of the engine bay then onto the ground. Without the cowl the water runs onto the back of the engine which can then seize the engine cover bolts. If you run without the engine cover the water goes into the valley of the cylinder head damaging spark plugs, coil, injectors.

On 9/8/2021 at 6:17 PM, balancerider said:

@Eagle N series petrols for sure 

N47/57 seem pretty sound. 

Agreed, the diesels of that generation seem pretty tough by comparison to the petrol's. Maybe due to the lower operating temps/greater thermal efficiency of a diesel engine that help to not cook gaskets and seals etc.

These little 4 bangers seem to get a bad rap around the place, but are they really that bad by comparison to the 6 and 8 cylinders of the same era? Sure they suffer oil/coolant leaks, valve stem seal leaks, timing chains and guides failure etc  but what N series engines of the same generation don't have issues? Is it due to the lack of power output compared their big brothers that the 4s receive their bad reputation? Maybe they are just the engine we love to hate?

Keep in mind that if you increase the oil hole diameter in the rail it will reduce lubrication to other engine components.