Neeed help 2/2006 4.4L misfire, out of time
 

OK, I really, really need help.

2005 BMW X5 4.4L engine.

I purchased it at 146K miles, now has about 163K miles. (Super clean inside, seemed well taken care of).

Prior history that I know was that prior owner hydroplaned and hit yellow barrels. I got super lucky and found and replaced for both doors and front fender (driver;s side) from salvage yard.

Drove it without any real problems for about 11 months. The only thing I ever noticed is that often when I would start it up, after about 2-3 minutes, the rpm would nose dive and it would die or almost die. Other than that, no knocks, or rough idling, or anything.

Week before thanksgiving, I pulled into the car wash, and I was leaking oil badly. I immediately checked the oil topped it off, drove it home and parked it. No stop engine low oil pressure light came on.

First guy replaces (1) Oil pan gasket, (2) alternator bracket gasket, (3) oil filter cap, (4) water pump, (5) thermostat (there was a small leak out of the weep hole, and the thermostat had thrown codes).

After waiting on the parts, it all got installed.

On the drive home, it ran OK at first, but then it started running rough. At some point, the stop engine low oil pressure light came on and I immediately pulled over. I checked the oil, but everything was sealed up, turned it back on, and no warnings came on. Subsequently, the low oil pressure light did not come on again, but it ran rough.

I checked the VANOS solenoids on the Bank 2, they were clean, cleaned them with MAF cleaner put them back in. No change.

Guy number 2 comes to work on it at the house. Very meticulous, checking everything. Bank 2 has all the misfires. He finds that the eccentric shaft sensor on bank 2 is broken. Wait on that part, then he also changes the valve cover gaskets. He also tests a lot of the parts they seem OK.

We fire it up this morning, still misfiring.

He checks the coills, and the one all the way at the back on Bank 2 (8?) shocks the heck out of him. He has an extra coil, he swaps it out, it no longer shocks him. But it still knocks, and backfires on what appears to be Bank 1.

This is kind of expensive to throw parts at, and actually parts are hard to come by.

But the present plan is to change out the coils on Bank 1, that is where the backfires are happening. I have suggested if this does not fix it, should our next step just be the cam sensor and/or crankshaft sensor?

I am really, really stuck. Been without this car for about 3 weeks now. If this helps, when he had the valve cover off, he looked at everything, and everything looked good up top. He had no indications that it had ever run dry, or was damaged in any way.

If you have any suggestions (burial is not a suggestion) please let me know. This is very frustrating and disheartening especially when you hang in there after a week or so, and crank it up and it is no better than when you started.

Thanks.

RTW

You need to read the codes with a real bidirectional scanner and if you are seeing "P" codes those are from a generic scanner and not always showing the real problem.

The Foxwell nt-510 or nt-520 are great and you don't need to be computer savvy....


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Scan
 

Agree with EOD. Really surprised that you didn't mention anyone scanning the car. You can't do anything without doing that first. I second the Foxwell 510. Mine goes with me everywhere. Stop firing the parts cannon at it and slow down with proper diagnoses. I don't see anywhere that you replaced the spark plugs? My 05 had a misfire, I scanned it and saw which cylinder it was. Swapped coils first, no change so obviously plug.

UPDATE
 

My long national nightmare continues. It has now been 4 weeks since it crapped out on me. Just as a recap, and putting things together, when I picked it up after the gasket changes, I drove it about 20 minutes before I started getting a Stop Engine Low Oil pressure signature.

So far, this is what we have thrown at it:

Bank 2 Cam position Sensor (A) (the one with the pig tail),
VANOS solenoid intake Bank 2,
eccentric shaft sensor Bank 2,
4 coils,
3 plugs,

Also cleaned up the wiring on Bank 2 VANOS solenoid, wires were brittle.

It seemed to me that it began running much smoother when VANOS 2 intake was switched out. I still got misfires, 2,3, 5, 8, but it did not backfire hardly at all, and overall less noise.

So here is the kicker, it was running smoother, and we let it run longer than we had previously, about 20 minutes, we were about to go take it for a test drive around the block when we got out Stop Engine Low Oil Pressure light. Before we had never let it run 20 minutes, so that must have been the deal. Up to temperature enough to thin it out?

I am very disheartened, I can't really believe this because it ran like a champ before.

So I still have these problems: misfires, out of time, and now Stop Engine Oil Pressure Low after 20 minutes. We checked the volume and it was at maximum.

There are plenty of threads around about low oil pressure, most say the pump almost never fails. We are changing out the oil sending unit in the morning because its just cheap to do so. But I am wondering about people saying the Vanos seal can leak oil and drop pressure. Are they talking about the O ring that fits between the solenoid and the block, or something else? Could that be the thing that gives me the combo misfire and low oil pressure?

So far we don't think anything is wrong with the bottom end, and he has visibly inspected the top end and says it looks very clean.

he. does have a scanner a very sophisticated one that has over 240 parameters, so we are looking at that.

One thing to note on that, we are not getting any VANOS solenoid codes(we were before we changed it out)but still gettin a A camshaft position sensor Bank 2 code, which we have already changed out.

The rest are misfires.

So, obviously, the big deal is the Low Oil Pressure, but it may not be real if the oil sending unit was bad, but it seems like that would go off at the very beginning, and it seems it has to heat up and get to temperature before it goes off.

Any help or thoughts appreciated.

You have two concurrent problems going on. I feel bad for you, because the technicians' haven't done their job correctly.

The N62B44 has a two-stage oil pump. The first stage is used during start-up and once the oil is warmed up, this is deactivated and then second stage is activated to provide more pressure at low engine speeds. Pressure specs at the pump with room temperature 20*C oil are 1 BAR at idle and 4-8 BAR at full unladen engine speed (6500) . Why didn't your previous technicians thread an adapter with a hose to a gauge. At the oil pressure warning sensor port. This is common sense diagnostics.

Camshaft bank codes can be caused by stretched timing chains, a failed hydraulic tensioner or a damaged guide. Really need to be using INPA in the correct menus to determine what's going on, and to determine if the timing is indeed correct.

Third, all coils should be bench tested, along with plugs inspected.

Because the oil pan and sensor were removed/changed was the oil sensor reset procedure performed ? What about the ram_backup cleared, this has to be done once vanos solenoids are replaced.

https://accuratediagnostic.blogspot....n62b44-v8.html

Mechanical oil pressure gauge is #1 thing to do. STOP "throwing" parts at it(your words). I agree with Aurelias, you have 2 problems. Your misfires are from your timing chains being toast. Trust me, I know it is an "N" 62, not "M". I have an N62 in my shop that came out of an 05 that the guides failed and engine was toast. SO, it does happen. But, you keep throwing parts at it and hope it is an Oring. That engine is done.

The N62B44 has a two-stage oil pump. The first stage is used during start-up and once the oil is warmed up, this is deactivated and then second stage is activated to provide more pressure at low engine speeds. Pressure specs at the pump with room temperature 20*C oil are 1 BAR at idle and 4-8 BAR at full unladen engine speed (6500) . Why didn't your previous technicians thread an adapter with a hose to a gauge. At the oil pressure warning sensor port. This is common sense diagnostics.

Have not done that. I will ask him to, but just understand the Low Oil Pressure. warning did not come on until about 8 pm when he was packing up to leave.

Camshaft bank codes can be caused by stretched timing chains, a failed hydraulic tensioner or a damaged guide. Really need to be using INPA in the correct menus to determine what's going on, and to determine if the timing is indeed correct.

Second time someone has mentioned the timing chains being stretched. Sorry for my ignorance what is the INPA?


Third, all coils should be bench tested, along with plugs inspected.

He did test all the coils, and inspected all the plugs. Bench tested the coils.

Because the oil pan and sensor were removed/changed was the oil sensor reset procedure performed ? What about the ram_backup cleared, this has to be done once vanos solenoids are replaced.

I am pretty sure nothing was done to reset the oil sensor. What does one due, is that through the software, coding machine?

On the ram, I have cleared the codes from the scanner, but I don't know if that is same thing. Again, what would that procedure be?

When you say the engine is toast if the timing chains are stretched, can you not just replace the timing chains? And how would you know if they are stretched?

I appreciate your comments, maybe it will help me towards a resolution.

The bigger question is why aren't your two previous technicians working here in this thread to better learn how to perform diagnostics and the repairs that they made that did nothing to solve the issue or at least keep enough of a record for the next guy. BMW's are complex vehicles, and as they age passed 10 years dealer's no longer have techs that know how to work on them 'old stuff' and multiple compounding problems arise as the previous 5 owners allowed deferred maintenance to mushroom into a giant clusterfck. Did you even read the link to the blog I posted ? That's my work.

Just to make it clear you are going to end up with a few scenarios, so to save your time let's just get right to the point so you can move on with life and get your car on the road working great, and then we can manage expectations of what's realistic.

-check to determine if you had reached the mechanical totaling value of your vehicle, and end up by selling it for a loss, or keep pouring money replacing parts and diagnostic hours until something sticks
-hire a competent workshop to solve problems from beginning to end
-learn on your own, but this takes training, investment, time, tools, experience, and you have to be willing to make mistakes and potentially lose use of your vehicle for awhile while waiting for parts or finding out you don't have the tools needed.

I am pretty sure nothing was done to reset the oil sensor. What does one due, is that through the software, coding machine?
That's a question to call your previous technician and ask if they did it, and write it on work report. BTW, you should upload and post your invoices and technicians' notes performed from the last times it has been worked on.
On the ram, I have cleared the codes from the scanner, but I don't know if that is same thing. Again, what would that procedure be?
Clearing active codes is not the same as deleting the ram_backup

INPA is a special OEM software tool that can show if your timing is off, has a engine rough running menu, and comes with a couple utilities like tool32 which lets you execute special backdoor commands like reset the positions and force learning for the oil sensor, vanos solenoids, camshaft timing learning. THere's been a couple TSB's issued where replacing oil sensors without the correct reset procedure causes all sorts of misfiring and weird problems. That's why I even mentioned it in the first place, again a lot of backround details I'm not even getting into because it would require me to write a scholarly publication. If you want that, go to my blog.

Maybe it's time to take it to the 'car ninja' https://gmwks.com/

Quick Post and will do an update later: But do you need software to reset the Valvetronic actuators? We did the deal where you turn the key to position 2, then pump the pedal 10 times, then wait a minute, then start it and let it run for 5 minutes, but I saw on a YouTube video Nathans workshop where he said the only way to properly reset them was with the proprietary software. Any ideas on that? And no, it is still not working.