4.4 V8 All 8 Misfiring??

[Watfordx5]

Hi all

I'm new to the site, had my 04 bmw x5 4.4 v8 about 3weeks now. After a week of owning the car my engine light came on for a few days then went off. This morning about 30 seconds into my journey the light flickered and came back on along with the car juddering. It was like driving on cobbles and had a loss of power. I drove to a garage where he said it was misfiring and after a diagnostics check he revealed it said ALL 8 CYLINDERS were misfiring. He was a bit baffled so cleared it incase it was from previous work that had been fixed but not cleared. He then started it up again this time it only showed only cylinders 1 and 4 were misfiring, any ideas why anyone? Im not the greatest with cars engine wise. Could it be the coil packs? Or more serious? Help would be great as I don't want to get ripped off so wanna be clued up. Thanks

[Guest Mister Dabsy]

All eight threw codes for a reason so I would suspect MAF, engine ECU but this would depend on the other unmentioned codes that were cleared

[Watfordx5]

I'm taking the car elsewhere for a second opinion as the guy was a bit of a clown. Will the fact that he cleared the problems effect the next person who looks at it? Expensive fix? Thanks for the help

[Greydog]

You really need someone with Autologic or dedicated BMW diagnostic software. The ECU has a memory so someone with the right kit will see the "local history" Many things can cause misfires but all 8, that's unusual. As Dabsy says MAF prime suspect but there are others, I would find a Bosche Auto Centre or BMW Specialist £50 on diagnostics is cheaper than guessing or doing nothing and causing engine damage.

Have you contacted the seller?