N62 minimum valve lift - Page 5

cmyachtie · #41 02-20-2016, 06:01 AM

Just signed up here, was googling my E60 N62 real cold starting issues and ended here....interesting thread!
FWIW, for those being concerned about the .8 mm setting being "out of spec", when I hooked up my car to INPA I DISCOVERED THAT I am already running at the .8 mm setting and I can only assume that I arrived at that setting thru the dealer's software update done two yrs ago (or has been so since new) and if the E60 N62 engine can safely run this the E53 N62 should be able to do so without any problems as well.
Also should mention I still have the cold start stumble and SES light occasionally with this setting have 105000 Km's on her.

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LVP · #42 02-20-2016, 08:21 AM

When I first looked at mine it was at 0.1mm. INPA shows a range in the green up to 0.8mm. I'm at 0.7mm and have only had one stumble so far, but the temps here are silly warm. I haven't had consistent -15C temps to truly test and find the best setting. I'm not replacing the levers unless BMW does it on warranty for them being part of the bad batch

cmyachtie · #43 02-20-2016, 04:40 PM

My setting has been at the .8 setting for at least the last 4 yrs and get a couple of the misfires every winter not enough to really go crazy fixing it but read on this thread about replacing the o rings on injectors think I'll try that though.
http://www.xoutpost.com/bmw-sav-foru...m-failure.html

Dellpc · #44 12-19-2016, 04:36 AM

Hi,

I have read thorugh this thread and got some good information. Hopefully you can help me with a similar issue to pin point the cause.

I have a 2004 E61 545i (N62 engine) and I started to experience cold start rough idle/misfire issues when temperatures dropped to around 5 degrees Celsius. The severity of the problem depends on how cold it is outside and how much time the car has not been driven. I think it basically means that if it is very cold outside, the car will cool down quicker and at some point the engine is cold enough for the problems to start. With temperatures around 0 degrees, it takes about 12 hours sitting before the problems start, but add in a cold strong wind and the problems might start earlier.

I have INPA and I have been monitoring it a lot lately. I just replaced the MAF sensor (new Bosch) due to air/fuel mixture problems. MAF was reading too much air and the mixture during idle was way off and I had the CEL on because of that. Now this problem is solved, but the cold start issue has still remained just like it was before MAF change.
I have tried different valve lift values. Before changin the MAF, the value was set to 0,0mm, although in idle INPA live data showed around 0,25-0,3mm. After MAF change, I had to change the valve lift to 0,4mm due to the idle was a bit shaky with 0,0mm setting (before MAF change this setting was ideal).

Here comes my main question. What should the valve lift be while starting a cold engine? I have monitored the INPA during the morning cold starts and it is very confusing since sometimes the valvelift is around 6mm right after start and then goes down after a minute or so to the predefined value (like 0,4mm) and sometimes it goes straight to the 0,4mm after start up. If the latter happens, it will usually idle very roughly and misfire errors will quickly pop up. Should the valve lift be 6mm everytime I start it and the engine is completely cooled down?

Dellpc

bcredliner · #45 12-19-2016, 12:34 PM

What do you plan to do if it is not what it should be?

What cylinders are misfiring?

FYI--This is and E53 X5 forum.

Dellpc · #46 12-19-2016, 02:13 PM

This is the closest thread I found from the internet about N62 engines so hopefully you are fine the fact I'm not owning a X5. It seems that X5 owner now a lot more about this engine than others.

What I would like to know is what is the standard behavior of valvetronic ECU during start up in cold weather. If I know the ECU working logic it would bring me closer to finding the caise.

Edit: there are no specific cylinders that misfire, could be any of them. Usually two random cylinders end up with misfire error.

bcredliner · #47 12-19-2016, 02:27 PM

Does the engine sound normal when you cold start it. Do you happen to hear a whining type noise for a couple of minutes?

Dellpc · #48 12-19-2016, 04:02 PM

Here is a short video of the cold start. Unfortunately I accidentally stopped it too early, but it still helps. Also a thing I noticed while looking at the video is the NKP angle value on the bottom left corner. Before starting the value jumps around. I should look into that next time.

https://www.youtube.com/watch?v=eZI6w5k8lxQ

cmyachtie · #49 12-19-2016, 11:49 PM

I also have read about this on many different forums and have played around with valvetronics settings can't say with certainty that it made much or any difference for me, however when the first time it (morning stumble +CE light)happened again about a month ago, I started my research on this again and have been keeping my gas tank at least half full as I read an SIB on this as being the first culprit according to BMW. And this has improved things for me thus far now also I have suspected (this is just me with having worked on my own cars over 50 yrs)vacuum leaks as a potential culprit and after replacing some of the rubber hoses last winter, I suspected the CCV item #1 in the diagram below and before I was going to throw >$100 at this problem decided to wrap the connections ( 3 places) in electrical tape or shrink wrap since I am partial to the first used it and despite having had temps pushing in the -20C range lately have had no more problems with the cold morning starting.
Hasn't cost me a dime and works for me......so I'd suggest to give it a try what have you guys got to lose......?

One of these days am going to rig up my own smoke setup and really prove I had a vacuum leak, but don't hold your breath...LOL

RealOEM.com - Online BMW Parts Catalog

WOULD love to get feedback on this if this works for any of you.

cmyachtie · #50 12-20-2016, 07:20 AM

Quote:

Originally Posted by Dellpc

Hi,

Here comes my main question. What should the valve lift be while starting a cold engine? I have monitored the INPA during the morning cold starts and it is very confusing since sometimes the valvelift is around 6mm right after start and then goes down after a minute or so to the predefined value (like 0,4mm) and sometimes it goes straight to the 0,4mm after start up. If the latter happens, it will usually idle very roughly and misfire errors will quickly pop up. Should the valve lift be 6mm everytime I start it and the engine is completely cooled down?

Dellpc

Mine is now set at .80 currently which I believe to the "default", as I have had a kombi software issue for which I had the car at the dealer recently.
Which also supports my theory that although this setting maybe a factor, there are other issues at play causing or at least contributing to my cold start problem.

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