MAFS cleaning
#1
MAFS cleaning
Anyone do it here? I have read on other forums, googled it and it seems to be a good thing to do. Some sources even said it can throw gearbox errors, performance cel's, etc.
Last edited by H20boy; 04-08-2010 at 11:13 AM. Reason: edited title to 'MAFS' instead of MAF for clarity
#3
#5
I have cleaned a few VW New Beetle and Jetta MAFS for performance issues (usually 2.0 and TDI) with good results. I looked at the platinum wire before cleaning and it looked like 'fuzz' or hair growing on it so I sprayed it with brake cleaner and GENTLY used compressed air to finish cleaning and drying. I have also replaced some that looked fine but had failed and did not respond to cleaning. I have tried cleaning some MAFS on AJ27 cars with hesitation upon acceleration and they still failed. I cleaned my 1999 XJ8L MAFS when I replaced my timing chains, guides and tensioners because the wire was 'fuzzy' and I did not damage it so I guess it's a judgement call. Pull it out and look at it with a magnifying glass and be REALLY careful with the sprays and air blowers. If you ruin it you can always buy a new one. I have some used ones from working at the dealer years ago so I can always keep putting a different one on until the engine runs OK but most people do not have piles of parts (read PACK RAT) like I do.
bob gauff
bob gauff
#6
I don't clean them unless there is some indication that doing so will correct a problem. Cleaning them for the fun of it is risky, especially given some of the cleaning techniques I hear that are used. When these MAFSs sit behind a factory designed air filter, they do not pick up solid debris.
Like Bob, I have spares for Jaguars and BMW (pack rat too), so I can always swap out if I have a failed one
Like Bob, I have spares for Jaguars and BMW (pack rat too), so I can always swap out if I have a failed one
#7
Just Tuesday I had my MAF changed. After a fairly large job including the replacement of all my "hard-to-reach" hoses, I had the 0171 and 0174 codes. With no vacuum leaks found, a search of this forum pointed at the MAF as the likely culprit. I had new one in my Spare Parts Bin, knowing that it was just a matter of time until I was in need of it. So far so good, the codes are still absent, but it hasn't been long enough to tell if I am out of the woods yet.....
Brian
Brian
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#8
The MAF can be cleaned with CRC MAF cleaner but be careful with anything else, most highly volatile cleaners like this can damage plastic, stick with MAF spray only. If the MAF has any junk on it, a cleaning will improve the mixture response and give better running and mileage. This is the best simple tuneup you can do on an older car.
#9
Not generally as a routine maintenance step on a vehicle with no symptoms. I might do it once on a higher-mileage vehicle if it's not been done before, or if I have to "get in there" anyway to clean out the throttle body. I have a Toyota that had hesitation problems when accelerating; a quick spray of CRC QD Electronic Cleaner on the MAF sensor worked wonders. I would not hesitate to use the QD Electronic Cleaner on my Jag's MAFS, especially since I already have it. It looks very similar in composition to CRC's Mass Air Flow Sensor Cleaner, and after all, I had to use something before CRC decided to market a MAFS specialty product. That being said, I'm still a sucker and would probably pick up a can of the Sensor Cleaner if I didn't have anything else and had to buy something anyway.
As oldmots noted, some electrical parts cleaners are not plastic-safe. If you're going to do it, make sure you've got something appropriate for the task.
As oldmots noted, some electrical parts cleaners are not plastic-safe. If you're going to do it, make sure you've got something appropriate for the task.
#10
When I do use a MAFS cleaner, I stick with the product specified for it, although I would (uneducated) guess that contact cleaner is a similar or same formula. The two things important to me if I were to experiment are - plastic safe and residue free, the latter of which is significant for me.
#11
I am assuming that the sensor we are all talking about is the one right near where the intake tube connects to the air filter box? If so, this piece is ridiculously easy to get to, remove, spray, and reinstall within maybe 5 minutes. There is even a photo-illustrated do-it-yourself write up on the MaxPerformance website (if you are lucky enough to find the site up and running) that shows how to do this. With it being so easy, why would you not inspect and clean on a routine basis?
Doug
Doug
#12
I haven't looked for the one on my XK8 yet, but that sounds like typical MAF sensor placement to me.
I have generally subscribed to the theory that if there was much to be gained from a regular cleaning, then it would be manufacturer-recommended maintenance. It is usually quick and easy, and I don't think there's anything wrong with doing it on a regular basis. It's just one less thing for me to do/drop/break if I don't. I have heard it suggested that folks using oiled filters may benefit if they're prone to over-oiling.
I have generally subscribed to the theory that if there was much to be gained from a regular cleaning, then it would be manufacturer-recommended maintenance. It is usually quick and easy, and I don't think there's anything wrong with doing it on a regular basis. It's just one less thing for me to do/drop/break if I don't. I have heard it suggested that folks using oiled filters may benefit if they're prone to over-oiling.
#13
Doug,
The MAFS is actually mounted on the tube and portrudes into the air stream, and has a multi-pinned connector coming from the front engine harness on an AJ27. The AJ26 is a little different mounting setup. It is directly after the air filter and before the crankcase breather tube (for good reasons).
The reason you don't want to constantly clean it is because if it is setup with a factory specified air filter, it doesn't get dirty, assuming the air filter is changed with some regularity.
It only becomes a constant maintenance issue if some of the aftermarket filters are used, and there a many types and configurations. The sensor can become oil coated from the oiled type filters, then because these filters tend to be more porus, larger particulates pass through and eventually will stick to the oily sensor. This coating will cause the MAFS to incorrectly read air flow and can become the cause of rough idling, etc. It can also burn out the hot wire.
This sensor is a multiple one, bot MAF and AIT. It uses a hot wire sensor. It can be damaged or rendered permanently damaged if it is handled. Constantly cleaning it when it doesn't need cleaning can cause damage too. Not saying there is a high frequency of this, but once one realizes how expensive these these are, you tend to become careful just mucking with it.
The MAFS is actually mounted on the tube and portrudes into the air stream, and has a multi-pinned connector coming from the front engine harness on an AJ27. The AJ26 is a little different mounting setup. It is directly after the air filter and before the crankcase breather tube (for good reasons).
The reason you don't want to constantly clean it is because if it is setup with a factory specified air filter, it doesn't get dirty, assuming the air filter is changed with some regularity.
It only becomes a constant maintenance issue if some of the aftermarket filters are used, and there a many types and configurations. The sensor can become oil coated from the oiled type filters, then because these filters tend to be more porus, larger particulates pass through and eventually will stick to the oily sensor. This coating will cause the MAFS to incorrectly read air flow and can become the cause of rough idling, etc. It can also burn out the hot wire.
This sensor is a multiple one, bot MAF and AIT. It uses a hot wire sensor. It can be damaged or rendered permanently damaged if it is handled. Constantly cleaning it when it doesn't need cleaning can cause damage too. Not saying there is a high frequency of this, but once one realizes how expensive these these are, you tend to become careful just mucking with it.
#14
I fully agree that you shouldn't clean the MAF to much, once maybe but not (much) more, as it will affect its working as Steve explained. The ECU will adapt for inaccurate readings to a certain degree, but cleaning it too much will also destroy the meter, it is very sensitive.
However I am also sure that with stock filters a MAF sensor can be affected in its operating, as it will not hold all contamination in the air.
Just to give an example, driving at 50 mph or so (don’t have the exact figures with me) would consume about 60 liters of air per second, which is 216.000 liters per hour. Now translate this to 1.000 hours (so 50.000 miles), you get 216.000.000 liters of air. Depending on the air contamination (and knowing that the stock air filter will not hold every particle), I would think that there could be an effect on the MAF with the stock air filter at some point.
However I am also sure that with stock filters a MAF sensor can be affected in its operating, as it will not hold all contamination in the air.
Just to give an example, driving at 50 mph or so (don’t have the exact figures with me) would consume about 60 liters of air per second, which is 216.000 liters per hour. Now translate this to 1.000 hours (so 50.000 miles), you get 216.000.000 liters of air. Depending on the air contamination (and knowing that the stock air filter will not hold every particle), I would think that there could be an effect on the MAF with the stock air filter at some point.
#15
The illustrated "how-to" I referred to showed a close-up of soot that had developed over time on the fine wire sensor. I also noticed this type of thing happening with my old Corvette (in that case I was using a K&N but always was careful about the oiling). I believe that soot build up on these sensors is somewhat normal and careful occasional cleaning shouldn't be much of an issue. Merely the fact that someone manufactures an MAF cleaner seems to indicate that cleaning is sometimes needed.
Doug
Doug
#16
The only time I clean my MAFS is when it is dirty. When is that? Two times! I have not seen a need for quite some time however when I do I use CRC MAFS cleaner. They can cost up to $100.00. I still have a question unanswered and that is “Why do you want to clean it”?
#17
Doug
#19
The one and only one I bought from a dealer was $435. They are now available on some discount sites for $200 rebuilt with core charge. Jagbits still wants $402.