E92 N43 Issues

[b34thomas]

Hi everyone,

I've got a 2010 3 Series E92 320I SE with a N43 engine (106,000 on the clock). I've had the car for about 18 months and in the past few months (seemingly randomly) on some cold starts the engine light will come on and the engine rattles a bit. I normally pull over, wait a few minutes and restart and it's fine. However, in the last 2/3 weeks the issue has been getting more frequent (nearly every morning now). Still went after restarting every time. Also seems to be burning oil very slowly (indicator was halfway in September, and now in Feb it's just above the minimum).

Took the car into the garage today and they've read various fault codes (I'm not sure which ones however) and have come up with the below plan of action;

Replace Oil Pressure Relief Valve
New Timing Chain
Replace Exhaust Vanos Unit
Replace Denox Sensor

The bill for all the above is coming up around £2k which I don't really want to spend as the car is pretty old anyway. I was just wondering if anyone has had similar issues and if so what was the culprit? I don't want to risk the timing chain going but it feels like if that was the issue the loud rattling on cold starts would be there more/all of the time?

Any help/guidance would be really appreciated!

[helix402]

Standard faults for an N43. It does sound like it needs a timing chain. It will also need a timing chain tensioner and guides. NOx sensors are usually fine.

Just wait till it needs 4 injectors and a low rail pressure sensor too!

[b34thomas]

Thanks!!! Already had the 4 injectors...that was a shock!
Do you think it's worth just replacing the timing chain, tensioner and guides for now to see if that fixes the issue and leaving the other bits for a while?
Only want to keep the car going for another 6 months-ish, so trying to avoid anything thats not necessary. Also not sure if a faulty/stretched timing chain could cause error codes in the Denox and Oil Pressure Relief valve?
Cheers!

[Elliot2000]

Do you know what fault codes were listed when it was checked?

[b34thomas]

Have asked the garage, will let you know what they come back with. Thanks!

[b34thomas]

UPDATE. Here's the codes;

8 Faults
2EF7 Map thermostat, activation
30E9 Nitrogen-oxide catalytic converter, ageing
30C1 Engine oil pressure control, static
2A99 Crankshaft - exhaust camshaft, reference
30EA DeNox catalytic converter, sulphurous
2AF4 Nitrogen-oxide sensor, electric
2AF2 Nitrogen-oxide sensor, lambda linear
2AF6 Nitrogen-oxide sensor, lambda binary

[iSore]

Part exing it PDQ sounds a better plan! Chain and guides to start with but on these I would drop the sump and inspect the pick up pipe as there may/will be bits of plastic stuck in. The oil pressure solenoid can cause low oil pressure issues, £100 for the part and a couple of hours to change it - alternator off, and if you're lucky it will come out in once piece without breaking.

On the NoX sensor, buy a BMW one as the NGK ones are crap.

Vanos units don't tend to fail so much on these - cleaning the solenoids out should restore it to working order.

[Sardonicus]

Your fault code "2A99 Crankshaft - exhaust camshaft, reference" are almost sensor correlation issues (timing chain woes) agree with whats been said already , and to add not one of BMW's best engines , already witnessed a couple that have broken inj hold down straps

[b34thomas]

Thanks all! Just found out that sometimes they'll swap the timing chain when doing the brake vacuum recall, which is still outstanding on mine - so going to book that in and ask them to look at the timing chain/vanos at the same time. Really appreciate the advice.