[MalcolmV8]

Hi Everyone. I've been a member of another BMW forum for a bit but after a while found it was not very technical which is fine but not what I was looking for. I did some googling and found this forum which seemed a lot more hands on so I joined

Quick background on car. It's an 07 335XI with 117k miles. I'm the second owner and purchased it a little over 2 years go at 90k miles. Love the car!!

Quick background on me. Love working on cars, rebuilding engines etc. Most my experience has been on Fords and Hondas although I've worked on quite a lot over the years. So I know about cars, just not about BMWs... not yet anyways.

So here's what my post was from 4/3 (10 days ago).

Hey Guys,

Today on lunch break my car suddenly started missing real bad and wouldn't hardly drive with barely any power. Check engine light was on and car was very jerky and barely going. After a mile or so it just suddenly went away and car was crisp and full of power again. Like someone just flipped a switch.

After work I went to leave and first 1/8th mile or so it ran normal. Stopped at a stop sign and the issue returned real bad. Check engine light on as before. I couldn't get over 25ish mph and the car was shuddering and missing real bad. Came to a traffic light and the car just died. After several attempts to start it did and was barely running.

I noticed when I stopped at stop signs the nasty exhaust and unburnt fuel smell was really strong. I managed to get home (just a few miles away) and parked it. The entire garage stunk of unburnt fuel and exhaust smell. I had to open up the garage and air it out.

Pulled the spark plugs and they were all pitch black and fouled. The car was dumping a ton of fuel for some reason. To the point plug #2 completely quit firing and that plug was just dripping wet with fuel. I had just put brand new plugs in 3k miles ago so it's not like they were old.

I checked for codes and had these

P0302 - cylinder 2 misfire
P0139 - O2 sensor CKT slow response bank 1 sensor 2
P112C - manufacture control fuel air metering
P0159 - O2 sensor CKT slow response bank 2 sensor 2
P2298 - O2 bank 2 sensor 1 out of range durning deceleration

The P112C code catches my attention. What is the fuel air metering device on these cars? It would make sense that part has failed and caused the ECU to dump excess fuel completely fouling out my plugs and causing that massive raw fuel smell.

Thanks for any feedback and help guys
Malcolm

When asked about service history I posted this.

Coils replaced by BMW around 40k miles I think it was (forget exact mileage), plugs replaced 3k miles ago. High pressure pump has not been replaced but when those fail don't they reduce fuel flow? My car seems to be getting an excessive amount of fuel. I don't think the injectors have been replaced but it seems odd that all 6 would fail simultaneously. O2 sensors I don't know. I'm the second owner of the car and have some history but not all.

Update: called local BMW dealer and they show my high pressure pump and injectors have been replaced. Ignition coils were replaced at 39k miles.

Then another post:

The more I think about this I now recall where the car did this shudder and miss type thing briefly back in December but it only happened for about a minute and then cleared up and went away. It never happened again and I chalked it up to bad gas or low battery or something along those lines. In fact that's why I replaced the plugs in December thinking it was them but they looked perfect but replaced them anyways. So now that I think about it this has been something going out for a while that has now just suddenly completely failed. Humm

Then a couple days later:
OK so I was googling my error codes and specifically looking for hints on P112C. From what I've found it means "Intake air temp below threshold" or voltage to low. So if the car thinks it's sub 0F temps outside (very cold dense air) it would enrich the fuel mixture greatly to compensate right? However it was about 55 ~ 60F out so instead it was just an overly rich mixture flooding out the car causing my plugs to foul beyond belief and the car to drive like total crap because the A/F was completely off. Sound plausible? I need to hunt down the IAT (intake air temp) sensor and do some testing on it.

Then a question I had but nobody knows?

"Does BMW have the IAT sensor integrated into the MAF sensor like the newer Fords or is it a separate sensor?"

Then a few more days later I posted this:

Well I've been pulling things off the car left and right trying to find what's wrong. I found this sensor over on the intake manifold closest to the firewall. Notice there's also another small two wire sensor in what appears to be a vent tube from the valve cover to the intake tube.



I found another sensor just like it on the intake tube right before the throttle body.



Here's what those sensors look like. This is the one from the intake manifold. Looks rather oily and dirty. Looking at it closely it looks like a combination MAP sensor and temp sensor.



The two sensors. It doesn't show up in the pic but the one closest to the camera is from the intake tube and is rather clean. The one from the manifold is kinda gunky and dirty.
It looks like the exact same sensor but oddly the one on the manifold only has a three wire harness going to it but the one on the intake tube has a four wire harness so they're not used identically apparently.



I also noticed the intake tubing has a lot of oily mess in it. Not sure if this is normal on these cars or not. Sure seems like a lot to me.



Anyone know what those sensors are?

End post.

So at this point I was getting nothing but dead ends. I had picked up the BMW TIS from ebay but wasn't really finding what I wanted. So now I've ordered the Bentley workshop manual I found online which seems like the best I could find for the 335xi. Fingers crossed, it hasn't arrived yet.

I've also switched from believing it's a failed IAT sensor to a failed MAP causing the car to think it's in boost all the time and dumping tons of fuel. Once I get my Bentley manual I'm hoping it has the test procedures in there to test the MAP sensors.

So in the mean time I read a lot about the oily carbon build up on the intake valves and intake runner on the cylinder head due to the direct injection design. Problem with DI is no fuel is spraying over the intake runner and valves to keep them clean like a traditional setup with the fuel injector in the intake runner. So I pulled the intake off and lone behold it's unreal. I couldn't believe the build up. It's pretty horrendous. I'll need to scrape large chunks off the valves and head before even starting the media blast.

I think I'll pick up this media kit and blaster. Only $50 so not to bad.

http://www.eastwood.com/eastwood-sma...g-systems.html

Here's one pic I snapped. Not the best pic but you get the idea.



And that's where I'm at guys. Looking forward to been part of the online community here.

Malcolm

Just make sure you only use walnut shells, 335i has no MAF but dual MAP sensors, oil in the intake system is normal for a turbo car (blow by)

[e92_enthusiast_1]

Sounds like you're on the right track. Subbing to see when you find out more about the P112C code.

[MalcolmV8]

Originally Posted by index1489

Just make sure you only use walnut shells, 335i has no MAF but dual MAP sensors, oil in the intake system is normal for a turbo car (blow by)

OK will do on the walnut shells. I'll give them a call before ordering. Any idea on quantity? I see they have 10 lb bags and 50 lb bags etc. Not really sure how far say a 10 lb bag goes on a job like this.

Now that I've torn down the intake I see no MAF sensor. Just the two MAP sensors I found before and after the throttle body. Pretty much what Ford calls Speed Density system.

Yeah oil blow by from the PCV system sucks. Not much you can do about it though. I've tried catch cans that vent to atmosphere before but they stink horribly. On a turbo Honda I built a few years ago I run a hose from the catch can all the way to the back of the car near the tail pipe and you'd still occasionally smell it depending how the air was swirling around the car.
I may install a catch can on the BMW but it'll be plumbed to the intake so no stink. I know it'll only slow down the inevitable, the valves will still get all nasty as long as the catch can is plumbed back to the intake.

Originally Posted by e92_enthusiast_1

Sounds like you're on the right track. Subbing to see when you find out more about the P112C code.

Well if replacement MAP sensors end up fixing the problem then I'd say the P112C was it We'll see.

[purp_le28]

This same issue occurred with me 6 months ago. My vehicle finally just completely died after all the symtoms you have. I got it towed to my local BMW and they issued that it was "misfiring cylinders"..

[MalcolmV8]

Originally Posted by purp_le28

This same issue occurred with me 6 months ago. My vehicle finally just completely died after all the symtoms you have. I got it towed to my local BMW and they issued that it was "misfiring cylinders"..

They didn't give you specifics did they? like what sensor when bad or anything like that?

I was doing some searching on the media blasting stuff and found some Harbor Freight specials lol. There's a Harbor Freight store not to far from me so I may see if they have this stuff in stock.

http://www.harborfreight.com/portabl...kit-37025.html
http://www.harborfreight.com/25-lbs-...dia-92155.html
http://www.harborfreight.com/25-lbs-...dia-92150.html

[steel609]

I had the exact same symptoms as you have. Took it to my indy and he replaced #6 ignition coil and all fixed!


I have a 2010 328i xdrive and have had the #1 & 6 ignition coils replaced. #1 by the dealer under warranty at 45,000 miles, #6 by my indy at $135 with 53,000 miles.

Now that I know what to look for and how to fix, I need to keep a set at home just in case.

[MalcolmV8]

Originally Posted by steel609

I had the exact same symptoms as you have. Took it to my indy and he replaced #6 ignition coil and all fixed!


I have a 2010 328i xdrive and have had the #1 & 6 ignition coils replaced. #1 by the dealer under warranty at 45,000 miles, #6 by my indy at $135 with 53,000 miles.

Now that I know what to look for and how to fix, I need to keep a set at home just in case.

When you say exact same symptoms, all 6 of your spark plugs where completely fouled out and wet with fuel? or do you mean it only happened to your #6 plug as only that ignition coil was out?

[steel609]

Originally Posted by MalcolmV8

When you say exact same symptoms, all 6 of your spark plugs where completely fouled out and wet with fuel? or do you mean it only happened to your #6 plug as only that ignition coil was out?

Today on lunch break my car suddenly started missing real bad and wouldn't hardly drive with barely any power. Check engine light was on and car was very jerky and barely going. After a mile or so it just suddenly went away and car was crisp and full of power again. Like someone just flipped a switch.

After work I went to leave and first 1/8th mile or so it ran normal. Stopped at a stop sign and the issue returned real bad. Check engine light on as before. I couldn't get over 25ish mph and the car was shuddering and missing real bad. Came to a traffic light and the car just died. After several attempts to start it did and was barely running.

I guess stating exact same symptoms would be too much, as it didn't involve the rest of your scenario just the part in quotes.

Sorry if I seemed to answer incorrectly. Hope you find the cause and get yours running soon.

[MalcolmV8]

Cool just making sure

[purp_le28]

Originally Posted by MalcolmV8

They didn't give you specifics did they? like what sensor when bad or anything like that?

I was doing some searching on the media blasting stuff and found some Harbor Freight specials lol. There's a Harbor Freight store not to far from me so I may see if they have this stuff in stock.

http://www.harborfreight.com/portabl...kit-37025.html
http://www.harborfreight.com/25-lbs-...dia-92155.html
http://www.harborfreight.com/25-lbs-...dia-92150.html

When I am home tomorrow I will grab my service ticket and see exactly what they said. I'm sorry lol, this was awhile back.

[MalcolmV8]

Very cool, just curious. Might have some hints

[Hidden]

Very curious. It will be interesting to see what you find out the issue is. Also I would change the oil to be on the safe side with it dumping fuel like that.

[blegroswro]

Cool just making sure

[MalcolmV8]

Originally Posted by BPWFlorida

Very curious. It will be interesting to see what you find out the issue is. Also I would change the oil to be on the safe side with it dumping fuel like that.

I agree. Once it's running correctly I'll get the oil changed right away.

[///Mposter]

Well I am wondering if it is a DME issue . There is the thread about the injector mosfets going bad . The OP said there was some cut wiring on the harness below the engine cover. What I could not find out was whether he had no fuel or excessive fuel when he had misfires.
I am going to take an educated guess here and recommend you pull the DME cover off and search for water intrusion. If no water I present then search for the green connector than is next to the 50amp fuse. Make sure that the wire is not shorted, loose or disconnected. My guess is that the connector houses the power for ignition coils . If it is loose or shorted , it could cause you to have a lot of fuel that is not ignited by spark but instead by temperature or compression.
If someone that has a manual could confirm the ignition coil's power source, that might help.

Also I would check to see if any of your ground straps are broken or loose. Also check for rusty grounds. A lot of electronics work off of those grounds. The engine is floating by rubber mounts so if any of those ground straps break, sensors will not work. I use to make a kill switch for Hondas /acuras from one ground wire on their engine harness . If that one ground was lifted, there was no ignition/spark, but it would crank and crank. A lot of friends use to call and ask me about an engine swap not starting and they seemed to have overlooked that one ground .

[LuxAngelEyes]

I haven't read through the whole post, however i know that he Eccentric valve sensor is a fairly common issue. I had this with my car and it felt like a misfire and didnt happen all the time

[///Mposter]

After reading back through it again. You mentioned 117k miles on the car and the coils replaced at 40k. That's 77k miles on coils . You may just have some old coils. Maybe someone could lend you one of them for your cylinder 2 misfire. I would clean the fouled plugs first. Then if it misfires again, immediately pull the plugs to see which cylinder is fouled. It seems so weird that all plugs were fouled.

[MalcolmV8]

Originally Posted by ///Mposter

Well I am wondering if it is a DME issue . There is the thread about the injector mosfets going bad . The OP said there was some cut wiring on the harness below the engine cover. What I could not find out was whether he had no fuel or excessive fuel when he had misfires.
I am going to take an educated guess here and recommend you pull the DME cover off and search for water intrusion. If no water I present then search for the green connector than is next to the 50amp fuse. Make sure that the wire is not shorted, loose or disconnected. My guess is that the connector houses the power for ignition coils . If it is loose or shorted , it could cause you to have a lot of fuel that is not ignited by spark but instead by temperature or compression.
If someone that has a manual could confirm the ignition coil's power source, that might help.

Also I would check to see if any of your ground straps are broken or loose. Also check for rusty grounds. A lot of electronics work off of those grounds. The engine is floating by rubber mounts so if any of those ground straps break, sensors will not work. I use to make a kill switch for Hondas /acuras from one ground wire on their engine harness . If that one ground was lifted, there was no ignition/spark, but it would crank and crank. A lot of friends use to call and ask me about an engine swap not starting and they seemed to have overlooked that one ground .

Thanks for the info there. Sorry for the delayed response, I never received the usual email of an update and just happened to be manually searching and saw the replies. I assume the DME is in the passenger's back corner of the engine bay, under that cover with all the wiring? I found a unit that looked much like an ECU that could be the DME.

Originally Posted by ///Mposter

After reading back through it again. You mentioned 117k miles on the car and the coils replaced at 40k. That's 77k miles on coils . You may just have some old coils. Maybe someone could lend you one of them for your cylinder 2 misfire. I would clean the fouled plugs first. Then if it misfires again, immediately pull the plugs to see which cylinder is fouled. It seems so weird that all plugs were fouled.

I can see a coil or two been bad but all 6 failing at the exact same time seems unlikely. The other odd thing is how initially the car did this and then it instantly went away like a sensor or short as you mentioned above was turning it on and off. Then it was just happening constantly.
Is 77k miles really a lot for these ignition coils? Are they known for not lasting much? Typically ignition coils last a heck of a lot longer than that.

Well on another note my new Bentley manual arrived. Pretty sweet manual, lots of good info in the little I've read so far.



I was however pretty disappointed in that it has no test procedure at all in there for the MAP sensors. Simply shows where they are and how to swap them out and that's it. Doesn't touch on anything else with them. It's going to run around $200 to replace both of them from discount online stores. Not exactly cheap when guessing on failed parts. I'll probably hold on that till I can do more digging, like the wires you mentioned above.

Also picked up this blaster and a 25 lb box of fine walnut shells from a local Harbor Freight store for the intake valve cleaning I'll be doing here soon.

[MalcolmV8]

Had some free time this Saturday and figured I'd get the intake valves clean before pulling off the valve cover or any other parts where the messy process could get in.

Pushed the car out in the driveway and taped off a few things.



What an absolutely ridiculously messy process. Talk about walnut shell mess from hell. I was trying to use the shop vac to help but it wasn't much help.



The stuff got absolutely everywhere





You can only imagine how much of this stuff was EVERYWHERE. I do mean in every crack, crevice and hole.





To turn the motor over when doing the next set of valves I've seen people remove the cooling fan and use a socket in the center of the crank and turn it over. A much easier way is the starter motor right there. Simply remove the wire from the solenoid and just take a pair of pliers and touch positive power to it from the bolt above and you can pulse the motor over real easily and quickly.



I tell you what all that mess took hours to clean up. I had some 25 lbs of walnut shells in there. We had to take the shovel and scoop up piles after blowing under the hood with the air compressor. I do mean hours and hours. I took a break over night and started back up the next day. Pulling panels etc. It seemed the more air I blew the more walnut shells I'd find. I even got the car up on jack stands eventually and was clearing out all the under pieces, suspension etc.

I then degreased the whole side of the motor and underside where the oil filter housing has been leaking and then power washed it all nice and clean.



The valve cleaning process was quite the job too. I thought just blast it with some walnut shells and I'll be good but it wasn't quite that easy. I had to scrape a lot with a screw driver, tons of carb cleaner soaking and to get the tough stuff down on the valves I had to use carb cleaner with 120 PSI compressed air coming out of a long spout nozzle directly on the back of the valve to lift it. Then finish it off with more walnut blasting. I probably spent 4 or 5 hours of blasting and working on those intake runners. Made a huge difference though.

From this



This was almost done, doesn't look like I took a final pic doh! But you get the idea, this was almost done.



The really dirty gasket surface there is just from the carb cleaner splashing out all over while cleaning. Once the job was done a wipe down with some paper towels soaked in carb cleaner and they looked brand new.

OK now I'll probably pull the valve cover, inspected, resealed and also pull the oil filter housing and get a new seal in there. Then it'll be back to the original problem of the car not running

Making progress at least.

[mad1stgen]

Note to self. Bag the whole car with the exception of intake ports when doing walnut blasting. What a MESS !!!

Was the actual intake as gunked up as the head intake passages ? This is nuts. Lol.

[MalcolmV8]

Originally Posted by mad1stgen

Note to self. Bag the whole car with the exception of intake ports when doing walnut blasting. What a MESS !!!

Was the actual intake as gunked up as the head intake passages ? This is nuts. Lol.

Yes the intake has a coating inside of it too. It's not as bad as the cylinder head but it's got a rough feeling coating. I wasn't about to blast it since it's plastic but I'm going to have to remove the throttle body to ensure no damage to it and then figure out a way to try and clean it. I'm thinking some carb cleaner and a spiral brush like what you use to clean a baby's bottle.

I tell you what this issue is crazy. I did a little searching on it and I see some have tried water/meth injection but it doesn't keep it clean, it delays the build up is about it from what I've seen.
I got to thinking. Why not just tap off the fuel supply to the engine before the high pressure pump and inject regular gasoline instead of water/meth into the intake? I'm thinking a single smaller injector just continuously misting just enough to keep things sparkling clean in there.
Not sure if it would require a retune or if the BMW computer would be able to self adjust to that and reduce the fuel from the regular injectors to off set it.