Intake port cleaning for 135i

[TheRuss]

Hi folks,

After some mailing around I managed to find out that my local dealer has just bought a kit for cleaning the intake ports of our gunky 135is, however, as you might expect, it's not cheap.

My car has somewhere between 37k - 38k miles on the clock, so plenty to get gunked up, but I was wondering if it's worth hanging on, or if I should do it then somehow try to control it with seafoam or something?

I know Seafoam has proven to be pretty useless at cleaning a build-up of gunk, but I wondered if anybody had cleaned their intake ports and then tried to keep them clean with a regular application of Seafoam or something?

Otherwise, I've just installed a BMS OCC to try to reduce it, though OCC's don't seem to be a resolution to this problem from what I've seen.

FYI, my car is an N54 and I'm running Cobb Stage 1 at the moment. Also, I'm the guinea pig car for this garage, so I've managed to get a bit of a discount, which is why I'm thinking of doing it now.

Thanks
Russ

[SteveAZ]

I cleaned my valves at 30K, they were kind of nasty but not as bad as some pics I've seen. My OCC captures about 2-3 teaspoons every 1K now....other than that I see no oil loss. When I did my FMIC after getting the car with approx. 26K on it, everything was coated in oil and I installed an OCC a short time later. When I did my valves no oil residue was noticed...so I do think the OCC does do a pretty good job although I'm sure there are still some oil particles suspended that make it in to the intake.

I'm in the process of designing my meth kit so I'm not too worried about future build up and will just check it for myself. As for the seafoam...if sprayed in through the intake ie...removing a divertor valve hose or something it may be effective if done every once in a while....would I do it to my car....probably not.

[1speedbike]

FWIW, I'm at 66K and I haven't clean my valves yet, but I can sorta feel that the engine needs it.

I've been seafoaming with every oil change since like 30K miles, and I've had an OCC on for the past two years or so, but the OCC has barely caught any extra oil. It seems that I've had a lot less luck with mine than Steve has had with his. I'm pretty sure it's not doing much at all. I don't know how much the seafoam is doing either, because whenever I see the oil, it doesn't look any dirtier than usual, and when I don't do the oil myself, I ask and they say nothing unusual was in the oil. I'd at least hope for some more carbon gunk, but that doesn't seem to be the case.

There might be a few DIY's out there, especially on the e90post parts of the forums about cleaning the intake manifold and ports yourself. You can soak the entire damn thing in a bath of cleanser overnight and then just go to town with a hard bristle brush scrubbing everything out.

Also, a shop local to me that specializes in Audis (but I go to because they're awesome), does the carbon cleaning for $550, which is a couple hundred less than what I've been quoted by BMW.

[awns729]

Originally Posted by 1speedbike

FWIW, I'm at 66K and I haven't clean my valves yet, but I can sorta feel that the engine needs it.

I've been seafoaming with every oil change since like 30K miles, and I've had an OCC on for the past two years or so, but the OCC has barely caught any extra oil. It seems that I've had a lot less luck with mine than Steve has had with his. I'm pretty sure it's not doing much at all. I don't know how much the seafoam is doing either, because whenever I see the oil, it doesn't look any dirtier than usual, and when I don't do the oil myself, I ask and they say nothing unusual was in the oil. I'd at least hope for some more carbon gunk, but that doesn't seem to be the case.

There might be a few DIY's out there, especially on the e90post parts of the forums about cleaning the intake manifold and ports yourself. You can soak the entire damn thing in a bath of cleanser overnight and then just go to town with a hard bristle brush scrubbing everything out.

Also, a shop local to me that specializes in Audis (but I go to because they're awesome), does the carbon cleaning for $550, which is a couple hundred less than what I've been quoted by BMW.

Might be a noob question, but why would seafoam have anything to do with the oil? Wouldn't seafoam go through your intake and exhaust track?

[SteveAZ]

I think it really has to do with how hard you push the car and I obviously have no idea how you drive yours (or he drives his)...other than I know you have meth...When I first installed my OCC, the first time I checked it (after about 2K miles) it only had a residue. At that time I was having a lot of issues getting the car dialed and consequently wasn't pushing much boost, and definitely not for extended periods. That changed about 2500 miles ago. So YMMV...as I'm sure there are a few variables that affect this. The way I see it...cheap insurance...when you sell the car...sell it. It may also be helping to break the vacuum created by the intake/pressure in the crankcase and while you aren't collecting oil you are minimizing the transfer of oil. In my opinion the more obvious results weren't so much the collection of oil in my OCC but the lack of it in my CP when I removed it for my valve cleaning.

If you can DIY and enjoy working on the car...I'd do it and perform your own study.

[1speedbike]

Originally Posted by awns729

Might be a noob question, but why would seafoam have anything to do with the oil? Wouldn't seafoam go through your intake and exhaust track?

Haha that's a good question, actually. In all the seafoam DIY's and posts, they always say to do it right before you change the oil so that all the gunk can come out in the oil. When I seafoam I suck it up through one of the little vacuum lines that goes into the intake manifold, so yea, theoretically you're right it should get burnt up and go out the exhaust. My guess is that since the oil in our cars loves to go everywhere that it shouldn't be going, there's lots of little leaky areas, and the seafoam itself can seep into the oil through the piston rings and whatever other areas and into the crank case, and it might bring some of the gunk along with it. Huh.. I've really never even thought about it. Kudos to you for making me think! lol.

I would change the oil after a seafoam treatment anyway, just to be safe, but also because it's such a regular ritual to do the oil, so you might as well seafoam at around the same time to keep a consistent schedule.

[1911A145]

Originally Posted by awns729

Might be a noob question, but why would seafoam have anything to do with the oil? Wouldn't seafoam go through your intake and exhaust track?

seafoam instructs people to use there product in three different ways. some in the oil itself right before an oil change, some in the gas tank to help reduce the water and clean out the fuel lines and injectors, and then some through the vacuum port to clean the intake ports and valves, along with the pistons and related parts.

Because we have direct injection, the injectors bypass the valves. So if put through the vacuum lines, and gas tank, the best thing you will MAYBE do is help clean the injectors, and maybe the top of the pistons and MAYBE the bottoms of the valves. all the gunk and crap is on the valve stems though, so the only REAL way of cleaning them is... well... taking off the intake manifold and doing it manually.

OP: I did mine at exactly 50k miles and it was...well... BAD! I think I will do it again aat 90k miles. Then again, I would still recommend you get it done if you can get it for under $600. I paid $300 for mine and it is WELL worth it. I also changed my plugs at the same time and the car drives SO MUCH better than before.

If i were to use ANYTHING to clean the injectors, and treat the fuel system along with the pumps and seals, etc, it would ONLY be Chevrons "up to" 20 gallon fuel system cleaner with a full tank (a little over 14 gallons) every 3k miles. If it is REALLY bad, maybe BG 44k if you can get your hands on some for cheap. But I would trust the Chevron product regularly just fine over sea foaming a car that wont benefit from it. I would DEFINITELY STAY AWAY FROM ADDING IT TO YOUR OIL.

I hope i was somewhat helpful.

[PA135i]

My intake needed cleaning around 43K. They dealer did it and it was covered.
Now I use an indy shop and they recommend it every 30K.

[1speedbike]

Originally Posted by PA135i

My intake needed cleaning around 43K. They dealer did it and it was covered.
Now I use an indy shop and they recommend it every 30K.

How did you get the dealer to cover it!? I am extremely interested.

My RPMs have been hopping on startup for a long time now. It may be related to the gunk problem. But I also notice a definite drop in MPG for no reason at all, and my car just slowly stops "feeling" as fast. I know that I'm going to need it eventually, and my car is covered until 100K miles, so I'd really like to know what the dealership actually said, if you can please tell us

[awns729]

Originally Posted by 1speedbike

Haha that's a good question, actually. In all the seafoam DIY's and posts, they always say to do it right before you change the oil so that all the gunk can come out in the oil. When I seafoam I suck it up through one of the little vacuum lines that goes into the intake manifold, so yea, theoretically you're right it should get burnt up and go out the exhaust. My guess is that since the oil in our cars loves to go everywhere that it shouldn't be going, there's lots of little leaky areas, and the seafoam itself can seep into the oil through the piston rings and whatever other areas and into the crank case, and it might bring some of the gunk along with it. Huh.. I've really never even thought about it. Kudos to you for making me think! lol.

I would change the oil after a seafoam treatment anyway, just to be safe, but also because it's such a regular ritual to do the oil, so you might as well seafoam at around the same time to keep a consistent schedule.

Yea contamination through our low friction piston rings is plausible. Especially on a cold start I'd think. So if I was seafoaming, I might change the oil to be safe too. Especially since I have no idea how seafoam + oil changes the oils lubrication properties.

Originally Posted by 1911A145

seafoam instructs people to use there product in three different ways. some in the oil itself right before an oil change, some in the gas tank to help reduce the water and clean out the fuel lines and injectors, and then some through the vacuum port to clean the intake ports and valves, along with the pistons and related parts.

Because we have direct injection, the injectors bypass the valves. So if put through the vacuum lines, and gas tank, the best thing you will MAYBE do is help clean the injectors, and maybe the top of the pistons and MAYBE the bottoms of the valves. all the gunk and crap is on the valve stems though, so the only REAL way of cleaning them is... well... taking off the intake manifold and doing it manually.

OP: I did mine at exactly 50k miles and it was...well... BAD! I think I will do it again aat 90k miles. Then again, I would still recommend you get it done if you can get it for under $600. I paid $300 for mine and it is WELL worth it. I also changed my plugs at the same time and the car drives SO MUCH better than before.

If i were to use ANYTHING to clean the injectors, and treat the fuel system along with the pumps and seals, etc, it would ONLY be Chevrons "up to" 20 gallon fuel system cleaner with a full tank (a little over 14 gallons) every 3k miles. If it is REALLY bad, maybe BG 44k if you can get your hands on some for cheap. But I would trust the Chevron product regularly just fine over sea foaming a car that wont benefit from it. I would DEFINITELY STAY AWAY FROM ADDING IT TO YOUR OIL.

I hope i was somewhat helpful.

Thanks for the response. I'm a bit confused - can you explain where the vacuum port connects and where the vacuum lines connect? Running seafoam through these will also bypass the intake valves? Is that what you're saying?

[makrop]

Originally Posted by awns729

Might be a noob question, but why would seafoam have anything to do with the oil? Wouldn't seafoam go through your intake and exhaust track?

I will out-noob you...

Can someone explain to me what this is all about? I've heard the term OCC and stuff floating around but haven't looked into it yet. What needs to be cleaned and why? If someone has a good link to all this, that would be cool. Dont go searching though, I can do that myself if need be haha.

[MuNkY6913]

Originally Posted by PA135i

My intake needed cleaning around 43K. They dealer did it and it was covered.
Now I use an indy shop and they recommend it every 30K.

yes i would like to know where this was at? i'm in PA and i would drive to either side of the state. my warranty is about to run out so if you could let us know how that is covered that would be great.

[awns729]

Originally Posted by krop135i

I will out-noob you...

Can someone explain to me what this is all about? I've heard the term OCC and stuff floating around but haven't looked into it yet. What needs to be cleaned and why? If someone has a good link to all this, that would be cool. Dont go searching though, I can do that myself if need be haha.

haha, okay, so I've been reading about this a bit. We have our crankcase where we have lots of oil. And under extreme pressure (caused by high RPM and lots of combustion), some fuel can get into the oil because we have low friction piston rings that allow a little bit of blowby often times. This changes the chemical composition of the oil (lower viscosity and other stuff) and can possibly cause oil to vaporize a bit more than it normally does. When oil vapors exit the crankcase, they come around to the intake track (how? good question! i don't know, but probably through the PCV hose), which eventually means they'll get to the intake valves and that will be where the carbon build up comes from.

An OCC (oil catch can) will be installed between the crankcase and the intake path and "catch" the oil before it gets into the intake side of our engine, thus reducing build up.

Also, oil in the intake means oil will mix in with the fuel in the combustion chamber and lower the octane, which can potentially lead to knocking, so an OCC prevents this too (Edit: this part about preventing knock may not be accurate; not sure). Mostly, an OCC keeps your intake system clean and free of oil, and becuase that means less carbon build up, you won't need walnut shell blasting done as frequently in theory. In practice, I've seen mixed things about how much OCCs help. But lots of people have them, so they must make a difference I'd think.

This is my understanding of it as a n00b. Before you believe what I've written, I hope someone with more experience chimes in and confirms and elaborates.

[makrop]

Awesome. I can follow and wrap my head around all of that. I'm assuming this cleaning isn't something that is very DIY friendly? What about the installation of OCC? And are there any negative aspects of an OCC? Sounds like it is a necessary part and should have been there in the beginning, or something similiar to its function.

[awns729]

Originally Posted by krop135i

Awesome. I can follow and wrap my head around all of that. I'm assuming this cleaning isn't something that is very DIY friendly? What about the installation of OCC? And are there any negative aspects of an OCC? Sounds like it is a necessary part and should have been there in the beginning, or something similiar to its function.

I don't have the balls to DIY this. I don't think it's that hard though, but the idea of it scares me. I think if you're pretty handy you could do it yourself, so don't let my response scare you. Really depends where you are on the DIY scale. I'm just starting off.

http://forums.n54tech.com/showthread.php?t=16734 (pdf in first post is great)
http://www.e90post.com/forums/showthread.php?t=682116

Installation of an OCC is probably much easier than walnut shell blasting, but i've never done it.
http://burgertuning.com/instructions/occ_install.pdf

I don't know if there's anything bad about an OCC besides it being another potential place for oil to leak and that you have to remember to empty it out about once a month or every few months.

Hope this helped

PS sorry for hijacking thread OP

[makrop]

You are the man.

But I am not... and will not be doing THAT anytime soon... ha. Terrifying.

[SteveAZ]

Originally Posted by awns729

haha, okay, so I've been reading about this a bit. We have our crankcase where we have lots of oil. And under extreme pressure (caused by high RPM and lots of combustion), some fuel can get into the oil because we have low friction piston rings that allow a little bit of blowby often times. This changes the chemical composition of the oil (lower viscosity and other stuff) and can possibly cause oil to vaporize a bit more than it normally does. When oil vapors exit the crankcase, they come around to the intake track (how? good question! i don't know, but probably through the PCV hose), which eventually means they'll get to the intake valves and that will be where the carbon build up comes from.

An OCC (oil catch can) will be installed between the crankcase and the intake path and "catch" the oil before it gets into the intake side of our engine, thus reducing build up.

Also, oil in the intake means oil will mix in with the fuel in the combustion chamber and lower the octane, which can potentially lead to knocking, so an OCC prevents this too. Mostly, an OCC keeps your intake system clean and free of oil, and becuase that means less carbon build up, you won't need walnut shell blasting done as frequently in theory. In practice, I've seen mixed things about how much OCCs help. But lots of people have them, so they must make a difference I'd think.

This is my understanding of it as a n00b. Before you believe what I've written, I hope someone with more experience chimes in and confirms and elaborates.

Good response, you had me until here...

"Also, oil in the intake means oil will mix in with the fuel in the combustion chamber and lower the octane, which can potentially lead to knocking, so an OCC prevents this too."

Care to explain your perspective here?

[awns729]

Originally Posted by SteveAZ

Good response, you had me until here...

"Also, oil in the intake means oil will mix in with the fuel in the combustion chamber and lower the octane, which can potentially lead to knocking, so an OCC prevents this too."

Care to explain your perspective here?

Basically, when we talk about fuel, a higher octane means the fuel is more resistant to combustion. When oil gets mixed in with fuel, it lowers the octane (oil is more easily combustible than 93 octane gas, I believe). And that means that the fuel + oil mixture can ignite before the spark plug ignites it, thus causing knock. So if an OCC can prevent oil from getting into the intake track and then into the cylinder, it can reduce the chance of knock. Although, the oil that would get in would be so little that perhaps this is not a real world concern. Is that what you're trying to say?

This is a claim the BMS OCC makes: http://www.burgertuning.com/BMW_335_oil_catch_can.html
Edit: They don't actually say it prevents knock, but they say oil mixing in reduces octane. I inferred the knock part, possibly incorrectly.

I've been reading on bob is the oil guy's webiste, on here, and looking up various products like OCC and trying to put that information together. So if I'm wrong somewhere, please let me know, but this is to the best of my understanding.

[1speedbike]

Originally Posted by SteveAZ

Good response, you had me until here...

"Also, oil in the intake means oil will mix in with the fuel in the combustion chamber and lower the octane, which can potentially lead to knocking, so an OCC prevents this too."

Care to explain your perspective here?

I agree with everything except the lowering the octane part. I think you'd need a LOT of oil continually getting into the combustion chamber to really have an effect like that on the probability of knocking. However, I will say that when installing my meth elbow (and when a lot of people install aftermarket charge pipes) I/they notice that the stock charge pipe tends to have oil splattered all over inside of it. That's no good, and an OCC supposedly prevents that from happening if it works. So far mine has collected almost nothing...

[SteveAZ]

Originally Posted by awns729

Basically, when we talk about fuel, a higher octane means the fuel is more resistant to combustion. When oil gets mixed in with fuel, it lowers the octane (oil is more easily combustible than 93 octane gas, I believe). And that means that the fuel + oil mixture can ignite before the spark plug ignites it, thus causing knock. So if an OCC can prevent oil from getting into the intake track and then into the cylinder, it can reduce the chance of knock. Although, the oil that would get in would be so little that perhaps this is not a real world concern. Is that what you're trying to say?

This is a claim the BMS OCC makes: http://www.burgertuning.com/BMW_335_oil_catch_can.html
Edit: They don't actually say it prevents knock, but they say oil mixing in reduces octane. I inferred the knock part, possibly incorrectly.

I've been reading on bob is the oil guy's webiste, on here, and looking up various products like OCC and trying to put that information together. So if I'm wrong somewhere, please let me know, but this is to the best of my understanding.

Interesting....I'm fully aware of what octane does but would have thought oil would be higher, not lower, although I've never tried to light oil on fire or compress it

I was thinking of when I had 2 stroke bikes and how oil collected in the exhaust if you mixed it too rich.

Isn't diesel a form of less refined fuel that has a higher percentage of oil? Aren't it's combustion pressures pretty high?

Hmmm, I'll have to look that up...I don't trust marketing statements...

[awns729]

Originally Posted by SteveAZ

Interesting....I'm fully aware of what octane does but would have thought oil would be higher, not lower, although I've never tried to light oil on fire

I was thinking of when I had 2 stroke bikes and how oil collected in the exhaust if you mixed it too rich.

Isn't diesel a form of less refined fuel that has a higher percentage of oil? Aren't it's combustion pressures pretty high?

Hmmm, I'll have to look that up...I don't trust marketing statements...

Well I'm not sure myself. For 2 stroke bikes, I'd guess that they don't run super hot, so they might not run anywhere near the point where fuel will ignite itself before the spark plug ignites it /So octane may not matter at all since we're not near it's limits. Whereas in our 300hp engines with advanced timing, knock becomes a real issue and therefore octane matters.

Diesel fuel is ~40 octane and those engines don't have spark plugs because it's designed in a way that as the air+fuel compresses, the fuel is Supposed to ignite byitself without a spark, just by the heat of compression.

So even if diesel has a higher percentage of oil and therefore a lower octane, this still works. Also, not sure what you meant by combustion pressures. As far as the compression of the air+fuel in diesel engines, that may be high. But the point is to ignite the air+fuel without a spark, and the only other way to do that is compress the hell out of, which will make it hot and then make it ignite.

Having said that, even if a little oil mixes into the fuel in the combustion chamber, who knows if an OCC makes a difference or prevents knock. Who knows if there's any knock in the first place without an OCC.

Edit: Also to not completely highjack this thread. OP, it seems most people do a walnut shell blasting and don't think the seafoam does much. If you feel like you've had a power loss, then do the blasting. Otherwise don't worry about it I suppose I'm at 60k and I don't think it's ever been done. I don't have any plans for the foreseeable future to get it done.

[SteveAZ]

^thanks for the reply...makes sense...I'll have to read up more on that aspect of it. I tend to spend more time researching the liquids we actually want to inject...water, meth, ethanol, petrol....

On topic...I be really suspect of how much good Seafoam would do....that carbon build up is some resilient stuff and gets very sticky as it breaks down...I did a combination carb cleaner and walnut blasting and also cleaned the valve seats.

I know a lot of people are afraid of getting shells in the cylinder. When I finished my cleaning...I taped off the intake to all the cylinders. One by one, I removed the tape from the intake, removed the coil pack (I had already removed all the spark plugs to make it easy to rotate the crank but put the coil packs in place to prevent anything from getting in there) and blew out each cylinder with compressed air when I was done to make sure there weren't any bits of carbon or residual shells in the cylinder.

It's not really that hard or that technical of a job...more of a methodical one that you need to think about what you're doing and use care.