M54B30 stalling when hot

[Ahmedsinc 414]

So wifeys 530i has thrown a new curveball. Starts fine, idle is a tiny bit rough when cold (known vacuum leak which I'm still slowly eliminating as time allows) but it has an intermittent stall from standstill when at operating temp. Does not stall when cold. Scanning with INPA showed a misfire fault on cylinder 1 but no other codes. Have replaced the plugs with new Bosch ones (old ones were originals I think, two of the ceramic insulators fractured when removed and all 6 slugs were unbelievably filthy) but no other parts replaced as yet.

Scratching my head a bit over this, am not sure it's a fuel delivery issue as the condition only occurs when hot, but I'm certainly no expert. What are the symptoms of a dodgy coil pack / packs?

Will be placing an order with Pelican shortly for new rocker gasket, fuel filter etc as I'm fairly sure none of the usual service items have ever been replaced.

Have had a go at googling the problem but the threads are annoyingly vague.

Learned suggestions appreciated - thanks

*Edit - spelling

Edited May 4, 2015 by Ahmedsinc

[BM WORLD 1283]

fix the vac leak 1st .

also does it start up straight away??

sticking throttle body ?

fuel pump dieing??

[polley 916]

Does it stumble and then die or just cut out straight away?

[Ahmedsinc 414]

Restarts fine. Feels just the same as stalling a manual. Go to put your foot down when pulling away and it just cuts out. No rough running or anything to indicate it's about to poop itself. No check engine light either, which I find odd.

Vacuum leak proving difficult to isolate. Have done all the usual suspects, about to redo valve cover as I used the gasket from the project engine instead of a brand new one. Fault codes are O2 sensors deviating rich, might yet be the sensors. Have got a new disa gasket coming to be safe, hoping it's not the manifold / secondary air rail / injector gaskets as they're a royal pain to do.

[charles28 136]

I found the biggest issues for mine were the hoses from the oil separator, all of them were split/cracked and leaking.

[hybrid 1043]

Remove the maf and smoke test it.

[_ethrty-Andy_ 2132]

Re vaccum leak, oil seperator issues are pretty common with this engine, I have also been advised by a dealership employee that the lower intake boot is also very common to crack and was later revised, not sure if this was at the change to M54 from M52TU, or later still. about $170 including shipping of parts from pelican and reasonably stright forward. i have just got my stuff arrive.

[Ahmedsinc 414]

Would the vacuum leak be a major contributor to the stall issue?

Am still bemused by the infrequent nature of the stalls, it's not every time the car pulls away from a stop, and it can go a few days running without any problem at all.

Both halves of the intake boot have been replaced with good used items; the two main hoses from the oil separator have been replaced; afm has been replaced, and every rubber bung has been renewed as well.

Rocker gasket weeps a tiny bit of oil straight onto the exhaust manifold shield so will be getting redone soon.

Only intake / vacuum bits that haven't been replaced yet are o-rings / gaskets, the flexi hose that runs from the oil separator, the oil separator itself, and the 'sucking jet pump' & its 2 associated hoses.

Gonna have to come up with a DIY solution for the smoke test, 12 hour shifts & a crazy amount of overtime has been destroying my chances of taking it to a shop!

New fuel filter coming as well, I suspect the original item is still in the car now - 155,000km & 14 years later. Woohoo for jap imports

[polley 916]

A vacuum leak would be there almost all the time. And would have to be huge to make it stall. My first thoughts were failing crank sensor

[Ahmedsinc 414]

A vacuum leak would be there almost all the time. And would have to be huge to make it stall. My first thoughts were failing crank sensor

I have had a couple people say cam and / or crank sensors. Hopefully I'll get enough time on my one day off this week to have another look via INPA and see if there are any new codes.

Wifey has also reported engine stuttering before stalling, but not every time. Apparently this has been happening for a couple weeks now, but didn't remember to tell me when I asked how the car was behaving.

Sigh

[allan 295]

Just a thought have you had a look at the idle control valve and what sort of fuel flow do you have to the fuel rail. When I changed the fuel filter on mine the fuel coming out of it was black.

[Guest MP0wer]

Could you get it scanned. Maybe your cam position sensor if not a bad vac leak.

[Ahmedsinc 414]

Made time to plug in the laptop and see what INPA could find tonight. 65, 227 & 228 were in the memory. 227 & 228 are my deviation rich from the O2 sensors, and 65 tells me the inlet cam sensor is on the fritz. No major surprise as the exhaust sensor went bad a few months back too. Fingers crossed I can make the time to fit the spare used sensor I have on Saturday, will add a new genuine one to the Pelican shopping cart asap.

Still need to come up with a decent DIY smoke test. Fault codes from the vacuum leak annoy me. Would be nice to drive the car without the check engine light as a permanent feature on the dash cluster!

[allan 295]

Would their be EML showing next to the check engine warning light?

[Ahmedsinc 414]

Would their be EML showing next to the check engine warning light?

Nope.

[Ahmedsinc 414]

Minor update - cam sensor replacement appears to have been a success. No reported stalls in + / - 600km driving.

Still need to come up with a decent DIY smoke test to isolate this fecking vacuum leak if anyone can help.

Chur!