Several Misfire 4.8i
 

Hello all.

Got an X5 4.8i and when I start it cold, I get misfire on several cylinders 4,5 and 8, if I drive about 400-500meters turn ignition off and on again, than the problem is gone and the engine acts normally.

New spark plugs and injector in cyl. 8. Swapped the coils and the error does not follow the coil so the coils seem to be ok. Is there any known malfunction that you know that could be causing it?

How cold is it when you start up. There is a known intermediate lever issue that can cause exactly this.

Valve cover oil leaks letting oil settle into the spark plug wells.... Goes away after burning off.

Just a wag....

It doesn´t matter how cold it is, 3°c or 15°c, always the same. The eccentric shaft and everything related to that have been changed.

Definitely check for oil in the spark plug wells as stated earlier. Also, you replaced one spark plug but if they all haven’t been replaced recently that could be your issue as well. You might have plugs that are in bad shape and don’t like the low rpms causing the multiple misfires that disappear at higher rpms. I had this issue on my 4.8i and 8 new plugs solved the issue.


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Less than a year since they were all changed, did check for oil on cyl 5-8 and no oil visible and spark plugs looked perfect.

I would check for vacuum leaks.


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Vacuum leaks
 

I second the possible vacuum leaks. Use the carburetor cleaner spray test method to help rule in or out.

Sounds like you have and issue with rich/lean... it can throw random misfire codes, but not linked to any one cylinder (the reason for this has to do wth how the DME detests misfires, CU calibrations, etc) The DME will declare a cylinder, but these are not NECESSARILY linked to one cylinder. (note: another give-away is a code of 'misfires- multiple cylinders'...this means the DME is seeing a lot of jiggle in the crankshaft accel and cannot decide which cylinder(s) to blame.)


Is this a cold start issue only?
Does disconnecting the MAF change this at all?
How old are your pre-cat O2 sensors?
What are your short and liong term fuel trims?
When you run a VANOS function test, results?

So I looked back at my pictures from the misfire issue I had last year. I was driving back from vacation trip to Disney. 6 hour trip. Probably 3 hours in. Began to run rough. Ran fine for three hours of highway driving but when I got to lower rpms on a side road it began to run rough. I scanned it on the spot and got codes for “combustion misfires several cylinders, misfire on 4, 5, & 8, and a catalytic converter conversion” code. Was all solved by new spark plugs. I was able to get home at highway speeds and slower acceleration on slower roads. Sound like your status? This was 20,000 miles ago.


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Im gonna say he replaced the plugs...


:cool:

I thought he may only have replaced the plug on cylinder 8 even though plugs was plural. Oh well.


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Yeah, I guess we will find out....

Well here we go again. Mine started doing the exact same thing(but its a 3.0si). I just fixed some rough running issues and hesitation from a dead stop. The main culprit was my DISA valve, I pulled it out and the entire flap was just gone. I tried look in the intake manifold to see if the flap was still in there. But my guess is someone removed it on purpose thinking it would add power, just like deleting IM flapper in a Honda. When doing my VCG, I found that the spark plugs were very worn out, so I replaced all of them and the coils too.

The DISA really had it running smooth for a bit, then suddenly it started running VERY rough on cold starts. And now that the temperature is dipping below zero at night, the vehicle will barely run in the morning on first start. But once it runs for about 30 seconds the idle smooths out and it runs fine. However it still have dead stop hesitation......again.

I didn't change the intake manifold gasket when I had the intake manifold off for vacuum line replacement awhile back, so that could be a significant cause of vaccum leak now. But it is still weird that the vehicle smooths out so quickly, and doesn't seem to have issues on a warm start.

Going to unplug the MAF just to see how she starts. That might give some indication to what is going on. Probably going to replace the IM gasket just for good measure, it's very cheap anyway. Might as well throw some Pre-cat O2's at it as well since they are surely as old as the vehicle.

How crappy are the intake tubes on these X5's?? On the E46's they were garbage, they develop micro cracks and cause misfire issues due to vaccum leaks.

Yeah I changed all spark plugs less than a year ago, but might as well check them to see if there are any problems with it.

The n62 does not have DISA valve so we can rule that out.

Oxygen sensors have been changed but I had the same errors that another member had, misfire on 4,5 and 8. So I´m gonna re-check spark plugs and make sure that tey are fine.

How many miles on this vehicle? It doesn't appear you've done coils yet. That's another thing that will make you chase your tail troubleshooting. You can swap coils all day long and watch the same misfires continue to appear. Replace the coils and suddenly problem is solved. At 20$ a pop it's a worthwhile venture if you can't locate a vacuum leak to repair.

About 103k miles. But if it were coils, the car would have misfire all the time.........maybe I´ll just change coils and spark plugs again and see what happens.

*edit* ignition coil on cyl 8 has already been changed.

Oh I don't think coils are your main issue. At 103k miles, they are definitely due though.

Also, worth mentioning. Again, not your main issue, but what plugs did you use? BMW's hate those 4 prong plugs or anything fancy like that. You want standard replacement, Bosch or NGK plugs.

I just unplugged my MAF the other day for a cold start, and it fired right up no issue. Small surge in the RPM and then settled right out like normal. No misfires and stalling. That basically confirmed for me I have a vacuum leak. A bit ironic that we are both having the exact same issue, but one is 4.8 and one is 3.0.

I just hate those Nxx engine from BMW lol. I used NGK 3199, if I unplug the MAF it runs like hell, so the MAF is ok and no vacuum leak.

Already spent over $9.000 in reapirs on it, and just about geting fed up with that piece of metal.

*edit* I just found out that NGK 3199 are not the right spark plugs, I was looking at another car when I took them out of the shelf. Will replace them with the right ones and hopefully the car will be fine :rofl:

Use NGK 4294


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I hear you. My X5 is just a work beater anyway. I am strongly considering just getting a Honda CR-V.

Let us know how the correct plugs go for you.

The spark plugs were the right ones, no oil or anything, everything looks clean as it should be.

Swapped ignition coils and will plug it to a computer tomorrow morning to see if the misfire is still isolated to cyl. 8.

I’m pretty sure the NGK3199 are not the correct plugs. They aren’t even listed on NGKs site as compatible. I once installed the wrong plugs. Ended up with multiple misfires before I installed NGK 4294 to solve the issue.


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Wtf is wrong with the quote button?

Unicorn is correct, the 4294 is the OE Laser Iridium Plug. 6441 is the Iridium IX. 3271 is the Double Platinum. 7100 is the G-Power Platinum. 4291 is the V-Power Copper.

Where did you get the 3199 from? Did some shop recommend it?

Only use the OE 4294. Some of the ones on the NGK site fit but are not compatible.


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All of those listed should work, their lifespans will vary though. But yes I would also recommend only using the 4294 which I mentioned is the OE replacement.

That’s just it. They don’t all work but they do fit. I used one of the listed ones on my 4.8i. Threw misfires everywhere. I contacted NGK and the shop I bought them from damaged them out in the return and I bought the OE 4294. Fixed it all.


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LOL...75% of the time the quote doesnt work on this website. Annoying.


1. Manufacturers, as in PLUG manufacturers, may say it is the right' plug, but that is only their opinon. The fancy, advanced designs are not OE....and while NGK may say they work, they may not. Subtle differneces in temp, cooling, flame-wavefront, etc, can happen in some BMW engines


2. FI (turbo) motors are MUCH more susceptible to these plug issues. I think timing is tighter AND thermal effects at the combustion point become more critical.


FWIW

When I say the right ones I meant that I did not use NGK 3199 like I tought. I used bosch 0 242 235 776. So spark plugs are not the issue.

Iridium IK20TT 4702 Denso Spark Plugs from eBay worked out fine for me.They were $38 for 8 spark plugs...

I think you must have a bad sensor. Or a computer having issues using info to provide the right fuel to air mixture.


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