Topic: Mass Air Flow Sensor Contamination with Supercharged 2.4L

[TecSolOnt]

  Anyone having any experience with their S/C cars as to what is causing the MAF to get contaminated.  I sent Dave a note at DDM as mine seems to be getting worse,  the intervals declining causing me to pull it and clean it more often.  Suspect with Memorial Day he will be a little while getting back to me.  Have had the S/C setup for about 4 yrs now , works great but this MAF contamination sees to be a growing problem.

  I have had issues since getting the S/C installed but it was about once every 1000 miles at first,  now it seems to be occurring in the 100 to 200 mile range.  I have an automatic and it screws up the downshifting (hard downshifts) as well as make the engine run a little rough.  Get codes , "lean on bank 1" occasionally  with it as well as it distorts the set up with the engine.  Each time I clean it with MAF spray , put the MAF back in it runs like a charm at least for awhile. 

  I have checked all the pipes etc. to make sure there is no air leaks. I don't believe it is related to the K&N air filter as it is kept clean and in working order, not over oiling it.  Is there something else I should be looking at?  Is it possible the intercooler, pipes are now having oil residue building up over time and that is adding to the issue?  Scratching my head on this.  Thanks!

[Critterman]

That is a new one.  I would pull your charge pipe and run a rag through it and see if there is any oil in it.  I would venture a guess it is the fact that the 2.4 doesn't have a PVC valve per se.  Check the vent hose for oil as well.

[TecSolOnt]

 Thanks Critterman,  excuse my dumbness I take it the charge pipe the one with the MAF in it? I will pull the vent hose.

 

[Sol Asylum]

Critter do you know how the super charger is lubed?  Does it get engine oil or does it have it's own oil supply? 

It is possible that you could have a seal on the S/C that is leaking a little and that is the source of contamination.

[nighttripper]

I installed a catch can from DDM. Haven't had any problems so far.

[Helios]

I do have MAF sensor contamination as well. I was getting a lot of oil through the charge tubes and in the intercooler, but I think it was resolved when Dave changed out the input and output actuators. Now I'm only getting a little bit. I also installed an OCC to help prevent any oil from getting to the MAF. I do get a random CEL with a misfire in cylinder 3. I was hoping when I upgrade my internals this would be corrected. BTW, Critter, I've been meaning to ask, how is Bix running with the new internals? I might upgrade my rods and pistons next year.

[TecSolOnt]

My engine runs great ,  no codes except related to this MAF issue.

I get the feeling my issue might be similar to Helios.  Could you see the oil in the pipes Helios ,  and what is an OCC?

 Sounds like I will clean out the pipes and vent hose first.  See what happens.

 The S/C has self contained lubrication,  my understanding so not like a turbo.  Wondering why I might want to put a catch can on it then?

 

[Sol Asylum]

OCC is Oil Catch Can

Even with a self contained oil system it can leak and get oil in the intake, have you checked the oil level in the S/C lately?  Also because of the way the crankcase is vented you can get oil from the crankcase in the intake even on NA engines.

[TecSolOnt]

  Yup , checked the oil,  just changed it myself not long ago.  It has never used oil, check it regularly.

  Guess when I have a look at the inside of the pipes it should give me a clue where it's coming from.  Thanks!

[Helios]

My engine runs great ,  no codes except related to this MAF issue.

I get the feeling my issue might be similar to Helios.  Could you see the oil in the pipes Helios ,  and what is an OCC?

 Sounds like I will clean out the pipes and vent hose first.  See what happens.

 The S/C has self contained lubrication,  my understanding so not like a turbo.  Wondering why I might want to put a catch can on it then?

 

Yes, I could see oil in the charge tubes and the intercooler. I took it all (charge tubes and intercooler) apart twice before Dave fixed the problem. I sprayed all of the parts out with brake cleaner and wiped out what I could with shop towels.

[TecSolOnt]

 I just took off the charge tube  that the MAF is mounted in and it looked very clean.  No oil residue or oily smell. Ran a cloth thru it and didn't pick up anything so now I'm wondering what it is.  I suppose the MAF could have some kind of an issue but odd that I use MAF cleaner and it goes away.  The dam sensors are so small no telling if there is actually anything on them.  Hmmmm.....

[Critterman]

Anything in the rubber vent tube?

SA - self contained gear box on the front of the SC.  If it leaked it would seize.

Helios -   Ran great all the way home,  spent the winter covered up, and then 8 weeks up on blocks while my wheels were being refurbished.  I did take it out a couple of times, haven't hit it hard as it only has about 700 miles on it.  I will say that it does have a traction problem as it goes past 3k and continues till I let off of it around 5k (1st and 2nd)  I just put new tires so hopefully that will change.   

Short answer - runs strong

[Sol Asylum]

I wonder if the problem isn't a bad electrical connection.  When you take it off to clean it and then reinstall it, it makes a better connection at least for a little while.

[TecSolOnt]

  Sol I'm starting to think that now as well. Critter  I checked the rubber vent tube off the engine and it was surprisingly clean, very clean, no trace of any oil in it, same as the charge pipes. Because of the work DDM did it does look like there are a lot of new connections made into the harness from the MAF.  Most electrical taped. We all know what happens with electrical tape when it gets hot so maybe there is an issue in one of those connections.

 Thinking back the issue always happens when the engine is running hot,  last time I was at idle for 20 minutes, hot day, A/C on sitting at the border waiting to cross and it came on, gave me a code.  In times past at low speeds , hot humid days usually when I notice it. Although admittedly it shows up to me when the transmissions is downshifting hard  into  1st and 2nd so of course I notice it when I am going slower.  I don't always get a engine light , in fact most times I don't so I know the MAF has had a problem when the TCM module starts acting up and the downshift issue starts.  The mystery of computer code,  clean the MAF the transmission goes back to shifting properly.  I do see the engine codes though for "lean on bank 1" usually when I check with the reader even if the engine light isn't  on.

  So maybe it is a electrical connection giving the ECM a bad reading , then the TCM is affected,   heat being in play,  then I take it out , move it around , cool it down.  There is a wrapped wire coming from a harness that it looks like DDM had to rig into the new MAF set up, guess I may have to start looking at this.  I did take the MAF connection at the top of it and re-seat it.  This may take some time to experiment with.

  Appreciate the input guys, any other thoughts on it would be helpful !!

 Added this after thinking about it - I have had situations when I first encountered this that the engine sat overnight before I cleaned the MAF (because I consulted the BB's here on what to do with this issue)   and at start up with a cold engine  the condition with the hard down shifting still existed ,  then I cleaned the MAF and it went away immediately.   Now this could be the cleaning of the MAF or moving the MAF  and wiring around to clean it that eliminated the condition.  It does suggest that cooling it down alone wasn't enough to fix the problem. 

   

[Critterman]

Interesting,  I don't know of any additional wiring required, or modification of existing wiring.  I wonder if it is only needed on the autos?  Have you heard back from DDM?

[TecSolOnt]

 No nothing from Dave yet,  sent him a note last Sunday.  Who knows where he is at with Memorial Day and all.

 It may something to do with the automatic.  Wouldn't they at least have to re-locate the MAF on a standard though as well?   I see lots of electrical tape on the wiring from the MAF into the main harness.

[Critterman]

I don't remember any, I will have to take a look

[Critterman]

Took a look.  Mine is taped up as well along with 2 spots in the wiring harness.  My guess is that they had to open the harness wrapping to get enough wire to go to the new location.  But that is only a guess.

[TecSolOnt]

  One thing I did notice is that just past the MAF there is a opening on the charge pipe that was covered by a rubber nipple and clamp.  The rubber looks like it was cracking pretty extensively and if under vacuum might have been collapsing into itself.  Cracks were big enough that if it was being sucked in they likely would open up,  however it is a few inches downstream from the MAF not in front of it,  not sure if that opened to let air in if it could create this problem.  I did find a new stronger nipple and replaced it today.  Car is running fine right now so I recorded the mileage and will start tracking when this happens.  Might replace the MAF itself at some point.

[Gentleman Jack]

Extra Air anywhere in the system will cause a problem because the computer is always checking the readings from the MAF and the (?) MAP and comparing them. Air after the MAF will register at the second sensor and cause problems.
I think.

[TecSolOnt]

  I kind of thought the same thing Jack,  no doubt it could change the air flow dynamics in the pipe as it becomes a leak.  My thinking was the nipple could get sucked inwards when you kick it down and the S/C really ups the PSI creating a vacuum in the pipe,  the cracks then open under that pressure then you have a air leak.  The nipple which was installed by DDM was quite soft rubber and it looks to be cracking at the edges of where it might flex if there was enough pressure to suck it inwards.  No other reason for it to be cracking so much unless it was flexing.

 Then again could be wishful thinking, time will tell.

   

[Dave@DDMworks]

Hey there,

Keep us up to date on the oil after replacing the nipple. Also, do you have oil in the intake tube right after the filter? There is a 1/2" hose coming from the valve cover that goes to the tube about 7" after the filter. Take a look in that 1/2" hose and see if you have oil coming through it and let us know.

Thanks,
Dave

[cooper1340s]

I used to have Stage II and later Stage III supercharger on my car. I did the installation of both myself and there were NO electrical connections needed anywhere near the MAF sensor. I never had any problem with sensor getting dirty or codes being thrown in 30,000 miles of driving with the S/C on the car. (It was a 5 speed though, not an auto). Hope you find your problem soon.

[TecSolOnt]

  Dave I checked the 1/2" hose and the pipe from the air filter , perfectly clean.  I did find an issue while doing this check that you might be able to help with.  The flex tube that attaches to the air filter pipe at the side of the engine  and then does a half circle up to the engine intake appears to be ripped.  There has never been any work done on this other than when you and Randy installed it . I can't quite see that side as it faces the engine but three  of the  ribs of that flex tube are broke and sticking thru the hose fabric, just where it mounts on to the pipe leading  back to the air filter,  about an inch  before the clamp holding it in place. This says to me it is safe to assume there must be an air leak right there as the ribs have popped thru the cloth.  Would these ribs just break from the heat?  It is also dirty and dusty right where those broken ribs are which suggests it may be sucking air in there. The rest of the ribbed hose is clean.  The material on the hose seems very dried out as well,  could it have aged from the heat etc.  and then the  broke ribs popped thru the material?   Here are a couple of pics:

http://s611.photobucket.com/user/TecSolOnt/media/IMG_9877.jpg.html?sort=3&o=1

http://s611.photobucket.com/user/TecSolOnt/media/IMG_9884a.jpg.html?sort=3&o=0



 It looks like this hose should be replaced, pretty awkward to get at.  Any suggestions?

[Critterman]

They have a newer and stronger flex hose now.  Unfortunately fi memory serves me right, everything has to come out including the SC to replace it.  Dave might have another way.