FAQ on Carbon Build-Up Issue (First Attempt) - Page 9

LeatherMan · 26th August 2005, 00:11

Now we are getting somewhere. I asked a couple of questions earlier that nobody answered and so I took it upon myself to do a little research. The first thing that I did was read up on smog pumps. Many of you may know this, but I will post it for those that don't. It appears that a smog pump is basically an air pump that is designed to help control emmissions. How does it do this... well on the M5 is it designed to start pumping outside air into the head right near or at the headers upon any initial cold start up. Supposedly the S62 throws a TON of fuel into the engine upon cold start up and this air helps to ignite and burn off excess fuel that would normally be thrown into the exhaust manifold thus smacking into the Cats. According to my source, a BMW mastertech at my local dealer, this system can become clogged with carbon build up. Specifically the airways to the engine become clogged or constricted and thus the engine senses that the "air flow is to low" in this "secondary air system". He is not sure why this happens but said that BMWNA blames gas. What kind of gas... who knows? His guess was that it was probably a combination of a lot of factors including gas, driving style, oil consumption, climate, and finally the design (shape and size) of the smog pump air passages. According to his research he said that most of the cases reported come from cars on the east coast. FYI, my car came from ffice:smarttags" />Floridatate> and is now in tate>Oklahomatate>. It turns out that he was familiar with the BMW "elaborate repair kit" for fixing this issue. He said he had done it on a few 540is and one M5. The "elaborate repair kit" is nothing more than a set of specifically engineered pipe cleaners. Why does it cost so much then you say? Well, the only way to utilize this repair kit correctly thus accessing the constricted air passages is to remove the heads. This is normally a time consuming job in itself, but he said specifically with the M5 that he was forced to remove the entire engine from the car in order to pull off the heads. Once the system is cleaned out there is still the possibility of it becoming clogged again. From reading this post I have felt nothing but doom and gloom related emotions, but while I was talking to the tech I realized that I really had no specific symptoms or problems that I could blame on this smog system clog. Also, I can't seem to find anyone else that has posted any solid negative symptoms or affects from this carbon build up other than that annoying SES light. I did mention some of the symptoms that I had experience recently with my car and he seemed to think that all of them sounded like a MAF problem. I hope he is right. Carbon build up on the head of a motor is a very common issue and something most people don't even worry about. That is not to say that it should not be addressed, but I am starting to ask myself why I suddenly care so much about this smog system? I definitely cannot say that I fully understand this situation, but my final question was the same as the one Hobbez posted.

What does it all mean man????
The tech basically told me that the clogging of this system should have no affect on the normal operation or performance of the S62. He even said that in his experience the smog pump on most BMW motors runs for less than a minute and only upon initial cold start up. He did mention that over time this system failure might lead to ruining the Cats and thus failures in passing emission tests. At the very end he even asked me if I had headers on the beast. I don't and told him so, but he followed that up with this little tidbit...
Supposedly there are only two header systems out there that are compatible with the factory smog pump system. I don't claim to understand this and he said he was only repeating what a Dinan rep told him in that the only two header kits out there that are compatible with the factory Smog pump system are the Dinan and the ACS setups.
This tech was one of the most knowledgeable people I have ever talked to. That said, he never claimed to fully understand the problem either. I spent almost a half hour with him on the phone and he never baulked at a single question I asked him. At the end I asked him why he was so helpful. He replied simply that he had been in my shoes before and he knows what if feels like. Please don't flame me or my source as we don't claim that any of the information above is the gospel concrete truth. That said, I hope I have added something of use to this discussion/debate. I know that I feel at least a tad better about the situation... knowledge is power. Of course I also firmly believe that ignorance is bliss and so maybe I should just take the little orange bulb behind the SES light out of the dash.
What do you guys think?
Regards,
Eric

mottati · 26th August 2005, 00:31

Quote:

Originally Posted by LeatherMan

Supposedly there are only two header systems out there that are compatible with the factory smog pump system. I don't claim to understand this and he said he was only repeating what a Dinan rep told him in that the only two header kits out there that are compatible with the factory Smog pump system are the Dinan and the ACS setups.

Eric, in a nutshell, i think you described the issue very well. This is what i understand it to be too.

I do think your tech is misinformed about the header issue, possibly some dinan marketing info, but the headers have nothing to do with the smog pump. The ports are in the heads, if they were in the exhaust manifolds or headers, that would solve the problem! And as far as I know ACS does not make headers for the e39 m5, only dinan, supersprint and rd sport. (maybe technik has some short tube 'manifolds' too).

You are right in that the ONLY issue is smog related. Unfortunately, for many of us, a SES light = smog test failure. If you live in a state with no smog testing, don't worry about it. If the rich mixture kills the cats, take them out too!

This was where my comment on tricking the obd2 system came from. I'm sure there is someone out there who can figure out how the obd2 system learns about the smog pump "flow", so if we tap into that circut, we give the dme the signal that the "flow" is ok, and problem solved, or at least hacked.
Mike

LeatherMan · 26th August 2005, 00:36

I asked the tech about tricking the DME also... he said that he thought that it could be done. We could either find a wire and tap it as you mentioned or I would think that PowerChip would be able to fix the SES light problem with a simple line of code... don't you?

Oh, and I think I misunderstood my tech. I think he was saying that only the Dinan and ACS(if they exist) are SMOG approved for street use. Anyways, that was a minor point. As you know of the last post I live in OK and we don't even have vehicle inspections let along emissions testing.

Eric

LeatherMan · 26th August 2005, 00:43

I just had a thought. If seafoam works for cleaning the heads by introducing it into the intake manifold, why could we not tap into the actual SMOG pump and let it suck some of that goo up into the air passages that are supposedly constricted thus cleaning them out? If it sucks outside air then that means we could find access to pouring or misting some kind of cleaning chemical into the actual pump cycle... right?

Eric

DavidS · 26th August 2005, 00:46

You could most likely trick the DME to think the smog pump is unblocked, but that will make the DME put far too much fuel into the engine during really cold starts.

I´d worry about the cats. If those get sprayed with too much unburnt fuel, you will need new cats.

Better then to only use the "Smog Pump Trick" at emissions testing.

Still, carbon buildup inside the combustion chamber is also not good.
Best is to find out what the very root cause is.

David

mottati · 26th August 2005, 00:48

Quote:

Originally Posted by LeatherMan

I just had a thought. If seafoam works for cleaning the heads by introducing it into the intake manifold, why could we not tap into the actual SMOG pump and let it suck some of that goo up into the air passages that are supposedly constricted thus cleaning them out? If it sucks outside air then that means we could find access to pouring or misting some kind of cleaning chemical into the actual pump cycle... right?

Eric

another good thought, maybe forcing something thru with compressed air. You'd think if this worked, bmw would have it listed as a 'fix' rather than the disassembly.

It'd be nice to have a diagram of the smog pump system to see where the air goes.
Mike

ard · 26th August 2005, 01:01

Just FYI- the little check engine light must come ON when the key is in position2 and then extinguish once started.... taking the bulb out will not pass CA smog. Do not ask how I know this...

wilsodh · 26th August 2005, 01:01

Quote:

Originally Posted by LeatherMan

Now we are getting somewhere. ....
What do you guys think?
Regards,
Eric

Now THAT'S informative. Thanks for doing some homework. There have been numerous pointers to the smog pump ports in previous posts, this further reinforces the scenario. Did your source have any comment on BMW's guidance to dealers on how to manage customers with this problem? I could see why BMW would 'blame the gas'... this helps make it ambiguous in terms of warranty coverage.

As we kick around ideas to address the problem less expensively, the bottom line is that the ports would not appear to have been designed in such a way as to assure proper performance over a reasaonble period of time under normal usage (including normal differences in gasoline quality). Here we might define 'reasonable period of time' as minimally the engine warranty period, including extended coverage. This is where BMW SHOULD reasonably assume some liability on cost coverage.ffice

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Since many of us probably couldn't get away with pulling the light bulb on the SES indicator, I still think this is worthy of a good stink. IMHO, if this is a known issue that is associated with the head design, we should make every attempt to put together the strongest case possible to 'encourage' BMW to cover this in good faith for those of us who may find ourselves facing this down the road without a proven alternative to fixing it cheaply.

Cheers,

Dave

LeatherMan · 26th August 2005, 01:05

Not to be a pessimist, but if BMWNA honestly does not know the source of this problem and further cannot even come up with a reasonable and surefire solution I kind of doubt we ever will. There are so many different cases in different areas on different years and even in different trim levels within the E39 5 series family (like the 540i). I personally think it is 60% to 70% design flaw and 30% to 40% other factors. The tech I talked to has only had one M5 ever even come in with this SASFTL carbon build up problem... he said it was extremely uncommon in OK and he doesn't know why it is so prevelent on the east coast. It is my guess that there are a lot less M5s in OK to begin with, but 4 cars sitting at one dealer on the east coast is REDICULOUS.

I can tell you that the tech I talked to was not your average mechanic either... during our last phone call I just found out that he is the President of the OK Bimmer enthusiast club. You can tell that he loves BMWs as well as his job. He seems like the type that is always trying to learn more and considering his admitted lack of first hand experience with this problem I can only believe that he has done some extracurricular reading/research on it. He must have access to all kinds of BMWNA service and warranty reports that we would/could never see. Maybe I should ask him if he could get a break down on the numbers of cars that have reported this problem and where each case has been reported...

Eric

LeatherMan · 26th August 2005, 01:26

Pulling the bulb was really just a joke. I could get away with it here in OK, but just the same I would like for it to serve its purpose. It is hard for it to do that when it is just always on. Maybe I could program it to get brighter when the car is experiencing a "real" problem. Once again... that was a joke.

I did kind of ask my tech about what they told customers with this issue in a round about way. He really did not seem to know what the SAs actually said to customers who might have been turned away. This guy was about as unpolitical as they come... I doubt that I would get the same type of candid, honest, and educated answers from the average Tech or SA. Maybe we should focus on getting a some information as well as a group of owners together and calling BMWNA about the issue. Wilsodh has a valid point but without presenting our side we won't get anywhere. I am just not sure what we can reasonably expect from BMWNA. I know that I am screwed in this situation, but maybe you low mileage guys should look into approaching BMWNA in a more aggressive way. We don't have the resources that BMWNA has and thus at the very least maybe we could motivate them into finding the source of the problem as well as good preventative maintenance schedule for those that don't have this problem yet but soon will.

IMHO, the "elaborate" pipe cleaner $8000 cleaning job every 50k to 100k miles is just unreasonable no matter how much you make. We are not driving Lamborghinis here... I bought this car so that I could have 400HP in a practical daily driver and since most of you did the same we know that many M5s are going to see 6 digit odos.

Eric