Re: Regarding cleaning the MAF

Hello my friends, as I stated on the tile I am having major problems with my 02 boxster, it is a base model with 160k miles, de-snorkled, and K&N filter(installed 90 miles ago) Here is the whole story:
A few weeks ago the after I installed the K&N the car started stalling and it would shut off by itself, I took the MAF out and cleaned it with MAF cleaner which worked great because the car stopped shaking. A week later the car felt slower so I hit the gas to see if I felt a huge difference in power and about 6800 rpm the engine completely stalled and all the pilots appeared on the dash but disappeared in a few seconds. After that, the engine was shaking and stalling like crazy, when I hit the gas it would start to backfire through the intake and then it would just shut off. I tried cleaning the maf again but with no luck. The car does the same thing everytime and it is imposible to rev it over 2k rmp without the car shutting itself after a few intake backfires. The car doesn't has the "check engine" or cel light on. I disconnected the MAF then started the car and it runs the exact same way as with the MAF connected, there was no noticeable difference and it would still misfire, stall, and shut off.
My question is, if the MAF failed, would the CEL light come on? could the MAF be the cause of the engine misfire and the intake backfire?
I also read that it could be the coil pack, fuel filter, an intake leak, timing chain tensioner failure, or the timing being way off.

If you guys have any guidance to narrow my search it would be greatly appreciated, I was thinking on going ahead and buying a new MAF but the fact that the CEL hasn't come on makes me think that it might not be a MAF problem.
Thanks a lot for your time and have a great day !
Vinicio
p.s. (sorry for my english, I'm Italian and I'm still learning haha)

... your English is excellent.
I don't believe in coincidences, so my guess is that your K&N filter and the MAF cleaner killed your Mass Airflow Sensor.
My recommendations are:
1.- Check all the intake for any leaks, from the MAF to the intake plenum.
2.- Change the MAF. Make sure it is the correct one for your car, which is e-gas.
3.- Change the K&N back to the OEM paper filter.
Good luck and
Happy Boxstering
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Thanks for the quick reply Pedro ! it's greatly appreciated. I will try those steps tomorrow, I took the MAF and it is the 986.606.125.01 so I'm just going to go ahead and buy one with the same number. I just hope it's not a timing tensioner or bad timing issue, I'll keep you guys updated, thanks again for your time Pedro ! Ciao

and resetting the mixture by disconnecting the battery (make sure you have the radio code if it is pre-2003). This step is important. When you start the car it may run a little rough for a few minutes but after then if the car generally runs fine with the MAF unplugged then the problem is likely the MAF.

FWIW, K&N guarantees that their filter won't ruin your MAF. They did an experiment where they submerged a MAF in their oil and it still had no lasting effect on the MAF. Anyway, they will pay for your MAF if the problem was actually caused by their filter. But I doubt it was. You are using the stock flat filter shape, right? The cone is a different story.

Also, I would check for codes even if you don't have a CEL light.

I did what you did to my '98 Boxster when it had 40,000 miles on it. I went through 2 MAF's! I was told that the K&N will not harm the MAF. I put the paper filter back in and do not modify anything regarding the motor. I now have over 180,000 and have not had any motor related issues since then!

I suggest that you spend your energies modifying the suspension and tires, etc for any performance gains. You will be much happier in the long run!

SJ

... engine components for better performance gains, but there are a few rules to follow in order to get the gains and not damage anything else.
1.- Use OEM components for the most part.
2.- Make sure that if you let the car breathe better (by changing an intake component) you also allow it to exhale better (my modifying an exhaust component).
The way to make more power is to have more air flow through the engine and have the ECU add enough gasoline to maintain the perfect mix.
But if you change anything in the air flow and you don't tell the ECU you've basically negated what you did because the ECU will try to bring things back to "normal"
That's why you should also have the ECU reprogrammed for the changes that you have done.
A better-flowing air filter should logically produce more power, but only if the above happens.
Same is true with a better exhaust or set of headers.
The car's ECU can and will adapt a little bit, but it cannot reprogram itself.
The reason why I say change parts with OEM when possible is because we know that those parts work well with our package.
The paper air filter allows more than enough clean air into the car. Even though K&N and other aftermarket filter manufacturers warrant their filters against MAF damage, we have seen enough of it happen to rule out coincidence.
When they are shipped, these filters come with much too much oil. Generally the same thing happens when an end-user cleans and oils the filter him/herself. they tend to over-oil it.
I did the same many years ago and decided that it wasn't worth the hassle and the potential of damaging another MAF, so I went with the OEM paper filter since.
The way that I can generate more power in these cars (guaranteed) is by, as I satated above, modifying the intake and exhaust and tying it all together with an ECU remap. I call this package the TechnoPower Kit.
It will generate 22 HP on a 2.5L and 30+ HP on a 3.2L using mostly OEM components (stock air filter, larger Porsche throttle body, larger and more efficient Tee, headers and ECU remap).
If you want more info on the TechnoPower kits, look here: [pedrosgarage.com] or contact me directly.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Thanks for the info Pedro ! I'll check those mods out, I plan to get an S model eventually(hopefully next year) so those mods would be perfect for it. By the way I forgot to mention something important, the car was overfilled with oil with a about a quarter(might be less but it's better to assume the worst, the electronic meter showed about 3 to 4 bars missing and I poured a little bit over a quarter in) and It was driven that way for about 3 weeks and a few days, it also has about 3 cups of coolant added but I haven't seen any signs of the "gel" issue. Could the oil overfill have something to do with the misfires? A "mechanic" told me that a quarter overfill would not hurt anything but still I decided to drain some of it and left it right at the top mark. thanks again for your time !

The thin film MAF is very sensitive. When you clean it it is very easy to damage it. I recommend never touching the film (always just use a liquid spray and light air, never rub). Some people have used Q-tips and that is much more likely to cause a problem than solve one.

hello ! well I used the "check" feature on the dash and nothing came up, plus the CEL is not on but I haven't used an OBD tool yet, I'm waiting to see how much can I troubleshoot myself. When I disconnected the MAF it seemed a bit mor stable for about 3 seconds but after that it went to hell again(same thing happened when I plugged it back in) I've also felt like it is harder for the car to start than it was before(sort of like a bad battery, but it starts at the first try) I also forgot to mentin two details, the car spent about 3 weeks with too much oil in it, I'm calculating it was less than a quarter but the electronic meter showed all bars full( I drained some and it is right at the mark now), also the were about 2 to 3 cups of aftermarket coolant added and I've been checking for the "gel" issue but I havent found anything, there is a strong possibility that last owner switched to regular coolant. Now I'm thinking the oil overfill might have something to do with it, burned seals or something related??? thanks for your answer my friend !

If there is a problem with the MAF it will make a mess of the fuel mapping table. When you unplug the MAF, you have to reset the table or the experiment is meaningless.

If you use an OBD-2 reader, check the fuel trims also and post the results here.

Quote
MethosSVT
Hello my friends, as I stated on the tile I am having major problems with my 02 boxster, it is a base model with 160k miles, de-snorkled, and K&N filter(installed 90 miles ago) Here is the whole story:
A few weeks ago the after I installed the K&N the car started stalling and it would shut off by itself, I took the MAF out and cleaned it with MAF cleaner which worked great because the car stopped shaking. A week later the car felt slower so I hit the gas to see if I felt a huge difference in power and about 6800 rpm the engine completely stalled and all the pilots appeared on the dash but disappeared in a few seconds. After that, the engine was shaking and stalling like crazy, when I hit the gas it would start to backfire through the intake and then it would just shut off. I tried cleaning the maf again but with no luck. The car does the same thing everytime and it is imposible to rev it over 2k rmp without the car shutting itself after a few intake backfires. The car doesn't has the "check engine" or cel light on. I disconnected the MAF then started the car and it runs the exact same way as with the MAF connected, there was no noticeable difference and it would still misfire, stall, and shut off.
My question is, if the MAF failed, would the CEL light come on? could the MAF be the cause of the engine misfire and the intake backfire?
I also read that it could be the coil pack, fuel filter, an intake leak, timing chain tensioner failure, or the timing being way off.

If you guys have any guidance to narrow my search it would be greatly appreciated, I was thinking on going ahead and buying a new MAF but the fact that the CEL hasn't come on makes me think that it might not be a MAF problem.
Thanks a lot for your time and have a great day !
Vinicio
p.s. (sorry for my english, I'm Italian and I'm still learning haha)

Backfiring through the intake is a sign the mixture's lean. This can be due to an intake air leak after the MAF or insufficient fuel or fuel pressure. The 02 Boxster's fuel filter is part of the fuel pump and when I replaced my Boxster's dead pump the fuel filter -- fine mesh in the pump's plastic base/housing -- the filter had plenty of filtering capacity left.

Another source of an intake leak is the AOS or an oil filler tube has cracked.

Have you read/checked any pending codes? When my 02 Boxster had is VarioCam solenoid fail -- though the symptoms did not include spitting back through the intake -- no error codes no CEL appeared but there was a pending code.

The problem may still be the MAF. The intake air temp portion is bad and the DME is fed the wrong info on the intake air temp and the mixture is too lean because of this.

With an OBD2 code reader/data viewer you can check for pending codes, view the intake and coolant temps -- with the engine cold they want to be close to each other and to ambient temperature -- and then observe the coolant temp rise about 0 to 1 to 2 deg F per second or idle time while the intake air temp climbs just a bit. It will run over ambient but not by much at least until the engine is fully up to temp.

Oh, wait I see you disconnected the MAF at the wiring harness and the symptoms remained. That poinits towards AOS or some other source of unmetered air and from the description of the symptoms, their severity, it is a big leak. In working the air filter box to intall the K&N filter, did you happen to knock loose the intake tube where it connects to the throttle body?

BTW, I'd ditch that K&N and stick with stock filter. The Boxster engine air intake is at a real dirty place and you want the best filter and the stock one is the best.


Sincerely,

MarcW.

Hello, I disconnected the MAF again but this time I reseted the ECU by disconnecting the battery, there is a huge difference in how the car runs, it still runs very rough and rmp's go up and down but now I was able to actually drive the car and rev it to 3.5k rmp without the car shutting off, there was a bit of backfire through the intake but only a couple of times whether with the MAF plugged it would do it every time I accelerated. So yeah there is a very noticeable difference between the mas being plugged and unplugged. Seems like the K&N did in fact kill the MAF. I'll have un update once I change the part, I already bought the new one and it should get to me in about 5 days, thanks everyone for your help ! it is greatly appreciated
Vinicio

On autohausaz.com (make sure you get the one designed for cars with e-accelerator - part # 0280218055).

Quote
MethosSVT
Hello, I disconnected the MAF again but this time I reseted the ECU by disconnecting the battery, there is a huge difference in how the car runs, it still runs very rough and rmp's go up and down but now I was able to actually drive the car and rev it to 3.5k rmp without the car shutting off, there was a bit of backfire through the intake but only a couple of times whether with the MAF plugged it would do it every time I accelerated. So yeah there is a very noticeable difference between the mas being plugged and unplugged. Seems like the K&N did in fact kill the MAF. I'll have un update once I change the part, I already bought the new one and it should get to me in about 5 days, thanks everyone for your help ! it is greatly appreciated
Vinicio

is one problem. BTW, that thin film portion of the MAF is 'buried' in that passage that runs through the MAF portion that sticks in the air flow. This is designed to protect the MAF from any airborne contaminates and to ensure the air flow is laminar past the hot film surface.

If the engine was overfilled with oil this can in partnership with a sub-par or sub-performing AOS 'foul' the combustion chambers and the plugs.

We already know even a "good" AOS is not very good at removing oil vapor from the air that passes through the AOS (engine smoking up on startup and high rates of oil consumption in some cars are I believe due to sub-par AOS performance) and if an engine is overfilled with oil this may overwhelm an AOS with oil vapor and this vapor of course gets fed into the intake and into the engine.

So, you should still consider the AOS and especially if the symptoms continue or other symptoms develop after you install the new MAF.

When you install it, clear the DTCs (to reset the fuel maps learned with the bad or disconnected MAF) and then see how the engine behaves. It can exhibit a bit of a starting reluctance and after run/idle rough, and compared to a healthy engine sound in fact pretty sick but the symptoms should be short lived as the new and working MAF and DME work together to properly fuel the engine.

If the rough idle, varying idle, smoking, spitting back, etc, persist, something else is wrong and suspect #1 should be the AOS.

To view/confirm this you'll have to remove the throttle body -- handle with care! -- and check for oil at the hose connection directly after the TB. This hose comes from the AOS. If there's oil wetness that's a good sign of an AOS problem. Also, check the TB. If its interior surfaces are oily that's another sign the AOS is a problem.

Sincerely,

MarcW.

UPDATE" Problem fixed, indeed it was the cigarette bud stuck in the TB what was causing the problem, after I cleaned every part I just put them back together and It worked perfectly. Thank you everyone for all your help and I hope this thread can be useful for someone who has similar issues.

UPDATE" I installed the new MAF today and even though it seemed more stable at the beginning, it has the exact same issues as before, same backfire, and it won't rev over 2k rmp I really had my hopes up with the new maf, I don't even know where to start know, I also put the old paper filter back and took the k&n out, can the intake backfire mess up the new maf ????

..... all of the air inlet tubes, hoses, fittings, etc.
Make sure the rubber sleeves that secure the intake tee to the engine are correctly in place and tight.
Make sure that the throttle body is tight onto the tee.
Make sure the Air/Oil separator hose (J-tube) is connected securely.
It sure sounds like you have a BIG vacuum leak.
Happy Boxstering
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna




Edited 1 time(s). Last edit at 06/23/2012 06:24PM by Pedro (Weston, FL). (view changes)

Hello pedro, I checked the best I could and I only found one weird spot, it is very suspicious though, it is the intermediate piece between the intake distributors, there seems to be a huge opening in the middle of it. I took some pictures, let me know what you think about it because I looked at other boxster engines and they don't seem to have that opening. Thanks again for all your help my friend !

That opening is right down the mold seam on the tee.
Check to see if it goes through to the inside.
It looks like it does because you have a lot of oil on those parts which can only come from the air/oil separator tube.
Remove the tee and check to see if the seam is compromised.
If it is, that's your problem.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Hi pedro ! I took the Tee and the TB out and yes it's clear to the eye and the touch that the crack goes through. It's in nearly 60% of the piece. I just cleaned the TB and I'm looking for the part number of that piece( hard to find haha) I might have to replace one of the sleeves as well because it broke when I took the T-tube out, thank you a lot for yout time and your help ! I wouldn't have found the problem if it wasn't for that, appreciate it a lot !

Minus 40 degrees... Is that Fahrenheit or Celsius?
Edited 1 time(s). Last edit at 06/22/2012 06:16PM by Laz. (view changes)

Minus 40 degrees... Is that Fahrenheit or Celsius?

Hi again ! hey I just realized something, I think the piece might be good even though It looks cracked. I did a few test for leaks in the just that piece alone and nothing...and now I just remembered that when I took the TB out, I found a cigarette bud stuck in the butterfly, it was holding it open, I think that might have been the whole issue, I guess the bud was stuck in the old filter and it fell in the tube when I put the K&n in. I'll put everything back together tonight and I'll let you guys know, I hope this thread can be useful for other people with similar problems, thank you again !

gets a hot stream of air from the driver's side radiator outlet. Intake air temp always is 12 to 15 or more degrees above ambient due to this.

Whenever you change the filter you have to be very careful the trash on top of the filter, on the foam layer does not fall into the air box. I have a shop vac and use a clean lint free paper towel to wipe the air box down.

I would strongly urge you to ditch the K&N and return the stock filter. It is the best setup.

Sincerely,

MarcW.