CEL NIGHTMARE HELP! p0491 code

skrewyluie, go to this link and scroll down. http://www.turnermotorsport.com/BMW-...2005-cars.aspx Do you know what engine number was in the e39 m5 model years 2000-2003? Could it have been the M62?

If a successful software supplier is found with a product that works this should be a sticky in the DIY section. Its only a matter of time before this happens to other owners.

Guys, I would also like to add my observations regarding this problem. I have an 04 745 that I purchased in October. The car has 120K miles. I also am having the P0491 code on a generic scannel and also have codes 2760 and 2768 on my peake scanner. On long idle 15-20 minutes will start to emit the smoke. Car runs fine with no other performance issues. So far I have replaced the secondary air pump, the y pipe and both diverter valves to no avail. I only get the P0491 and no other codes on the generic scanner. What is odd is that the peake scanner first detects the 2768 code (which BTW is not in the peake manual) when the 2768 code appears, it does not trigger the SES light. Later on when the 2760 code comes it eventually does trigger the SES.

Another interesting thing I noted (and I believe this to be significant) is that there is a high amount of suction from my dipstick tube and from the oil filler cap id I open up either when the car is idling. I also noticed when I was repalcing the y pipe and both valves I had removed the throttle body and could see there was significant amount of oil inside the intake manifold. This is very similar to when the E38 M62 motor has the ruptured OSV valve (PCV valve) on the back of the manifold plate on that engine. I have also replaced both the CCV valves and that has not changed the symptoms.

My guess is that the suction pressure present in the intake is causing oil to be blown into the intake valves and the "burned oil" going inot the exhaust it was is causing the clogging or "coking" that roadfrog refers to.

So, IMHO, I think if I can find the culprit as to why there is high suction in the intake that is sucking crankcase oil vapors into the heads then perhaps I can resolve my issue. Not sure if everyone is seeing this same suction thing. I know some have said they replace their valve guide seals and it was fixed. i can't help but think that perhaps in those cases they fixed whatever was making the crankcase not vent properly while having the engine apart doing the valve stem seals.

Couls it possibly be some type of intake manifold air leak? Not sure.. How about this.. Can all those that have similar issue right now check to see if they have high suction at their dipsticks and or oil filler caps while the motor is idling? In some cases when I remove the oil cap completely while idling, the engine has stalled. i do not think this is normal. At least on the E38 is is not.

regards, LarryD

Larry,

The suction is normal and in fact, if the suction is not there, other issues may be at play. It has something to do with how the CCV system works in our cars.

So why is there oil in my intake manifold? This is obviously a problem, and what I believe to be why the exhaust manifold is getting clogged up. Have you looked inside your intake manifold? It is failry easy to remove the throttle body and look insiide with a flashlight.

Originally Posted by Larryd745i

So why is there oil in my intake manifold? This is obviously a problem, and what I believe to be why the exhaust manifold is getting clogged up. Have you looked inside your intake manifold? It is failry easy to remove the throttle body and look insiide with a flashlight.

You have oil in there just bc either baf ccv valves or bad valve stem caps... So relax)
Usually 99% it's valve stem caps.
And yes air sec errors mean your air passages are clogged with burned oil again bc of stem caps. So your diagnosis is "worn stem caps, probably bc smbdy didn't change oil for 15-20k miles for 100 miles."

Like I mentioned. I have replaced both CCVs. I also have the service records for this car that shows it had regular oil changes at 10-12k miles at a bmw dealer. looking into the oil filler cap, inside the engine looks very clean.

Are the stems your referring to the ones on each valve stem? the ones that are inside each valve spring on the top side of the head? Anyone who has done the replacement have any pics?

Originally Posted by Larryd745i

Like I mentioned. I have replaced both CCVs. I also have the service records for this car that shows it had regular oil changes at 10-12k miles at a bmw dealer. looking into the oil filler cap, inside the engine looks very clean.

Are the stems your referring to the ones on each valve stem? the ones that are inside each valve spring on the top side of the head? Anyone who has done the replacement have any pics?

10-12k is way too much. Every 5k miles max or every 3-4 months.
Yep those valve stem caps... Very expensive
There is DIY by keif but it's not diy for everyone though

Originally Posted by adboles

skrewyluie, go to this link and scroll down. http://www.turnermotorsport.com/BMW-...2005-cars.aspx Do you know what engine number was in the e39 m5 model years 2000-2003? Could it have been the M62?

that is a 4.9 litre s62 engine. that wont do. anyone else outside of british columbia figure out where to download, buy source ecu modification for secondary air modification?

10-12k is way too much. Every 5k miles max or every 3-4 months.

And that is the info that I got from several Indy and dealer mechanics. Consensus is that, if the oil changes were done more frequently, we wouldn't be having these issues. That said, I will do an 8k mile change next and send in a sample to Blackstone Labs for analysis and see what they say.

Quick question. Is it only us over here in north America having the secondary air pump problems? I read that euro BMW's only check to see if pumps turns on and not its function. And that us BMW's check to see if the pump and all is actually performing correctly. If this us true why don't we just change our cars over to euro? Last year when I changed my car to euro I noticed the orange bar in the morning was shorter and my pump was on for a shorter period also.

Quick question. Is it only us over here in north America having the secondary air pump problems? I read that euro BMW's only check to see if pumps turns on and not its function. And that us BMW's check to see if the pump and all is actually performing correctly. If this us true why don't we just change our cars over to euro?

Hmmmm......VERY interesting hypothesis! I do know that the shop here that does the reprogramming, said they deveoped their program through someone in Germany.

I just went back through all the threads and no one from euro has been chiming in on secondary air pump problems. I just got p0491 for the past month so I know that I have that problem now and I have physically checked all my connections. Instead of me trying to fix this problem I will return my car to euro this evening after work and then I will wait and see if I get a p0491 back. If not, I think we may have our problem solved.

Goooood newsssss. Instead of being lazy this morning I went ahead and change over to euro before work. Just like I previously remembered. Shorter orange bar and cat warmed up quicker. Its 20 degrees colder this morning than yesterday also. My cel normally would be back by now but isn't. Ill reserve judgement until later though. Ill keep y'all updated!

Here an update as promised, no p0491 has come back! Its almost safe to say its gone for good. Just wrote fa in the cas. Then the lma module to change my vo to its Euro counterpart which is gl61 for an 02 745i

Keeping fingers crossed! I'd wait a bit to be sure it's gone for good. Mine would take up to a week for the code to return after a reset.

Mine always came back same day on second trip. Nothing yet.

roadfrog which gas station in washington state sells ethanol free gas

Breckenridge Dairy in Sumas WA. It's right on the main drag (Cherry St). There should be some in Blaine too. I know of three in Mt Vernon and six or so in Bellingham. Of course, all Shells and Chevrons in BC sell it.

Turner motor sports don't have a program for the e65. Has anyone found a program for the e65?
Thanks,

Originally Posted by MakaveliFaison

Goooood newsssss. Instead of being lazy this morning I went ahead and change over to euro before work. Just like I previously remembered. Shorter orange bar and cat warmed up quicker. Its 20 degrees colder this morning than yesterday also. My cel normally would be back by now but isn't. Ill reserve judgement until later though. Ill keep y'all updated!

How did you change over to euro?

Ncs expert. Modified fa. Changed car from gl63 to gl61.

I've been running for about a year with my sec air pump unplugged..Do not get any CEL do get the codes when i run a scan but car has been fine.
One of the valves in the manifold it broken so i disconnected the pump until i got around to fixing it..Probably won't bother now..
My car is Euro spec tho, maybe thats why i don't get a CEL up???
No noticeable difference without it connected

Originally Posted by MakaveliFaison

Ncs expert. Modified fa. Changed car from gl63 to gl61.

If you don't want to post about this, please send me a PM @ larryditizio55@aol.com

Thanks, Larryd745i

There is no secret too it. There is a DIY posted in bimmerforums on how to convert over to euro step by step.