grip grip

I recently purchased the car knowing it had oil leaks and the pre-purchase OBD scan showed the missfire codes. Anyway, I'd like to get it running right, so I'm looking for some advice. The car seems to have the smokey valves if I idle it for over 5 minutes, and the missfires seems to be limited to cold starts. The exhaust is very clean under regular driving.

I think I might have VCG leaks, based on the oily undercarriage. I recently rebuilt the vacuum pump and the oil pressure sensor/switch in an effort to stop the bleeding, but it's still there. Based on experience, do you guys/gals think I should order all the coils, plugs, as well as the VCG's and do it all at once based on the missfire codes and oil seepage?

seanjordan20

What is the year and mileage of the car? These cars leak from many places. I would suggest cleaning if possible and seeing how much it leaks and where. I would not spend unnecessary money if you don't have to because these cars always have something going on. It's used so when you get a used car that has not had the maintenance done right do the fluid change, plugs and troubleshoot the problems. Maybe it's the plugs and just 2 coils and 2 injectors. Start with a good fuel system clean and plugs to see what change you get then find what coils if any are bad.

I hope this made since I'm sure you will get some good recommendations here in addition to what I have said

grip grip

It's an '06 with 155k miles. I power washed it thoroughly the other day and I'm keeping an eye underneath. It seems like the leaks are going away by the day if that makes sense. Hopefully the initial leaks after the pump rebuild were from residual oil that was out of reach. I have driven it a half dozen short trips over the past two days, and the oil leaks have slowed dramatically.

I swapped the passenger side plugs today and it still misfired on startup. It didn't throw a code though and only misfired briefly. Eventually it will code and I'll be able to see if the misfire has cleared up on the one side.

And to add insult to injury, I let the battery drop very low the other day and I think the cars now in Transport Mode. Damn AC Panel has no power, so I have no AC. Way too hot to drive this tank with no AC, so it's going to be lounging until I clear that up. I have Inpa and I'm hopeful I'll find a easy tutorial on erasing it.

seanjordan20

Plug it up to a trickle charger. When I know I'm going to do work on the car I make sure it's fully charged. It's good you have INPA. It makes working on these cars a lot easier. Did you pull the codes yet or are you winging it for now. I would clear the codes and see what codes appear afterwards then go from there. It should give you the target cylinder/s. It might also be an air leak so keep that in mind.

grip grip

I pulled the codes and it intermittently gets misfire codes for all cylinders and I can hear a hissing coming from the engine. I'm also getting a lean code, so I suspect a vacuum leak also. I've searched for the leak with no luck. I've even sprayed the hoses with starting fluid while the engine is running and there was no affect.

I might send it to the dealership to remove the Transport Mode and check it for leaks. Of course I'd do the hose replacement myself, but I don't mind spending a little money to find it.

cmyachtie

A lot that has been said I agree with but I should add you may first do a good check for vacuum leaks, as you likely have one that closes up some as Engine warms up, also random misfires are rarely caused by coils as highly unlikely all coils are to be bad. I have been chasing random misfires in cold winter days myself and none of them are coil related. There is actually an SIB on returned and tested coils where all coils replaced by dealers were deemed to be not the cause of misfires.
Never let your battery go down as it will convolute the diagnosis with additional random faults.
On oil leaks... if you park car for lengthy period all oil eventually gets to lowest gravity points and sits where it normally doesn't, I have no oil leaks, however when I got surgery done two yrs ago car sat in garage for three months and had an oil leak puddles.....never before and never after, not even a drop.

Hope this helps

cmyachtie

Sorry I misquoted in my earlier post was not an SIB. I referred to but a repair manual reference instead.

grip grip

Thanks. I'm have an appointment to have a local BMW shop locate/repair the vacuum leak next week as well as remove the transport mode. Most of the residual oil from the original leak is now gone, and there is barely any dripping now. I still see a little coolant underneath, which I think is one of the o-rings. Hopefully the shop can sort that out also.

As for the misfire, I believe the reason it clears up once the car is warmer is due to being in closed loop. When I start it in open loop, the car ignores the cold o2 sensors, and therefore can't properly adjust for the vacuum leak. Once the o2 sensors are up to temp and the car is in closed loop, it adjusts just fine and purrs. I don't think it's a matter of the leak sealing up as the car warms up.

Gee_115

Did you ever get this fixed, where was the leak?

grip grip

The vacuum leaks were located and repaired (camshaft adjuster seals) but the cold start misfire is still intermittent. Maybe it's leaking from the VC gasket now, who knows. I just automatically rev the car to 1,200 RPM's for a good 30 seconds on every cold start, which seems to have eliminated the misfires.