e65 745i misfire/lumpy idle when starting from cold

[Patrick Bateman]

Noticed the idle when first starting the car from cold can be a bit lumpy for a bit and when engaging reverse to get off the driveway there's quite a lot of vibration, very odd. When starting the car leaving work tonight the EML flashed and I got a warning to drive moderately due to an engine fault.

This message and the EML disappeared again almost as quickly as it had appeared and the car drove completely normal. This only seems to happen when starting the car from cold although even when the idle is steady and the car is up to temperature I'd say I still feel more vibration than I'd expect in such a car.

Whipped out the laptop with DIS and INPA and got the following-









There are also secondary air system faults for banks 1 and 2 although not sure if they'd be connected to this?

[Patrick Bateman]

Thanks for the suggestions, swapping the coil packs sounds like a sensible approach, just hope access to cylinder 8 isn't terrible.

Regarding the fan, e65Ross mentioned he had the same fault when he owned it and it's nothing too important unless you're in a hot environment in traffic. I'll give it a look at some point though.

[Patrick Bateman]

Bloody torx sockets, the one thing my halfords socket set doesn't have.

[Patrick Bateman]

Access looks a bit tight-



Might just give cylinder 7 a go and if the fault moves then worry about 8. Not sure if cold weather makes this worse as it was -6 this morning and the eml didn't disappear, I had to switch off and restart the car. It had been fine all weekend.

[Patrick Bateman]

Bit of a palava tonight. Oil pressure warning came on but has since disappeared, got the car back to the house on a flat bed to be on the safe side though.

Now that it's dry I've noticed the car has been dripping oil all over the drive and there's a recorded misfire on cylinder 3 now as well as 7 and 8.

In the space of an hour since getting home there's a decent number of drops on some cardboard I've put down-




I can see the undertray is damp with oil but it's difficult to see the oil pressure switch without some disassembly. Hopefully that's the source of the leak then it'd also explain the warning that appeared.

Edited by Patrick Bateman on Monday 8th January 20:22

[Patrick Bateman]

Bit of an update, just got this from the car-



Am I safe in saying that since the misfire is now affecting 5 cylinders that's it's highly optimistic to think this is just something to do with the ignition coils? Reading about these symptoms online suggests the valvetronic intermediate levers as being the potential issue.

If the car is misfiring badly and the EML stays on, simply stopping and restarting the car instantly makes it disappear.

[Patrick Bateman]

Thanks for the suggestion.

It's got its MOT in 2 weeks so will get it looked at then.

Would the misfire disappearing after stopping and restarting the car be consistent with a breather issue?

Am I right in assuming you're referring to item 13 here-

http://www.realoem.com/bmw/enUS/showparts?id=GL62-...

Edited by Patrick Bateman on Saturday 3rd February 21:08

[Patrick Bateman]

This sounds so easy I'll hopefully just look myself tomorrow.

Only thing is I'd have thought this issue would cause a misfire all the time, regardless of stopping and restarting the engine.

That being said, even with no misfire the idle is generally fairly lumpy and not what I'd expect- nothing like how the V8 in my M5 idled. I can feel the lumpiness in the cabin myself.

Here's a video of the rev counter at idle-

https://www.youtube.com/watch?v=TRaYRxSdF-E

After a few minutes this was how it was idling-

https://www.youtube.com/watch?v=fM9_Vc6Gu78

Edited by Patrick Bateman on Saturday 3rd February 22:24

[Patrick Bateman]

Both diaphragms look good, I suspect they were replaced when the rocker cover gaskets were changed. Can't see any obvious split in the pipework.

All I can see is this-














The second one is the tubing coming from the MAF sensor. The rest are electrical.

Could that split being after the MAF sensor cause this? Or a frayed cable?

Edited by Patrick Bateman on Sunday 4th February 13:57

[Patrick Bateman]

Physically took them out, looked new.

I have thought the pump that runs when the car starts was a bit noisy but was never sure if that was typical. There are fault codes in the image up the page relating to secondary air mass and the pump.

How to I go about activating it in INPA?

[Patrick Bateman]

Cheers. Tried to run in INPA and DIS but get an error message from both when trying to activate the pump.

Here's a video of how noisy it is when starting from completely cold-

https://youtu.be/i_PAS6S6sbA

Stops at about 45 seconds. How bad does that sound to you?

[Patrick Bateman]

I have googled this extensively and read about the intermediate levers on the valvetronic.

Surely unplugging the valvetronic actuators would be a quick test to determine if it's related? I have read about increasing the minimum lift on them as half a solution.

My main query at the minute is if it is related to an air leak of some sort, would it not be an issue all the time rather than what I'm seeing?

[Patrick Bateman]

It sounds like a jet engine but there's also that harsh, random sound that doesn't seem right to me.

That sounds an easy enough check, that's good if you think it would get worse as it warms up.

As an aside, I can't imagine working on these every day. I'm 6ft and my calves felt properly stretched while leaning over into the engine bay.

[Patrick Bateman]

I've unplugged the sensors so I'll see when I start the car tomorrow how it behaves.

The sound from the pump seems to have stopped altogether now on a cold start.

[Patrick Bateman]

4 out of 4 cold starts since unplugging the sensors and there have been no issues whatsoever.

Looks like i'll be adjusting the minimum valve lift in DIS.

Noisy air pump has definitely stopped being noisy at all too.

Edited by Patrick Bateman on Tuesday 13th February 20:28

[Patrick Bateman]

It seems the minimum lift was actually 0.1mm as the default value and not 0.3mm.

I'll need to see what it does to cold starts but I've set it to 0.8mm just now and it's certainly made the idle far smoother. Only really started to improve at about 0.5/0.6mm.

0.1mm- https://www.youtube.com/watch?v=5fu9dpLezCI

0.8mm- https://www.youtube.com/watch?v=OVMqZxmyoBA&fe...

For anyone looking to do this it's quick and easy in INPA.

After going into the engine DME it's just into 'activate' and then 'VVT'. There it will give you a bar readout in mm which you can adjust up or down and then hit 'prog' to save the setting.

[Patrick Bateman]

Well we'll see how it fairs come the next cold start I suppose. Cheers for the help to you both.

[Patrick Bateman]

Started today and initially seemed ok then a misfire crept back in.

You know I think I'll say now that I regret buying this car, for a mainstream engine, the N62 is a fking disaster and not worth the hassle.

This is before getting to the likes of valve stem seals and the coolant pipe stting itself.

[Patrick Bateman]

iSore said:

Try removing and cleaning all four Vanos solenoids. If they've not been out yet, they will have badly blocked gauze filters.

Yes, they are horrid things.

How can they muck the design up so much after decades of making V8's.

[Patrick Bateman]

Back to the oil leak here. My usual mechanic has confirmed the upper right timing cover is causing it.

Premier Motors in Aberdeen reckon the job would be about £450 per bank to do the valve cover and upper timing cover gaskets.

The left hand side isn't leaking so could it make sense to only do the right hand side? As far as I can see, there's isn't a huge amount of repeat work if you were to do one side only then need to do the other at a later date.

My thinking is the car hasn't done 15k miles since the rocker cover gaskets were done (2.5 years ago), so I'm not worried about them as such. Also things like the spark plug tubes were replaced then, surely ok to re-use?