that_tg

Was at the local parts store and found a can of Mass Airflow Sensor Cleaner On the can it talks about the horsepower that is lost from a dirty Sensor and that you should spray this every time you change your oil.
Was wondering if any of you do this or if it is necessary to ever clean it?

aduggs

I do it every time I change my air filter - 30,000 miles or so. It's easy to do when you have the air filter already out. Also clean the throttle body while your at it.

I didn't notice any real change is gas mileage/horsepower after cleaning it - better to clean though.

that_tg

Great to know. Thanks!

Anyone else found this to help much? Will report back with any changes I find, not that I think it would be noticed.

spitanddirt

Depending on the type of mass air flow sensor(I haven't studied up on what our type is), the mass air flow sensor is designed to be "self-cleaning" using a hot-wire element of sorts. And normally, as long as you have a functioning air filter, the mass air flow sensor should never get dirty. The throttle body/butterfly valve, however, is a completely different animal and probably should be cleaned every 30,000 miles so as not to allow the valve to stick on carbon deposit buildup.

that_tg

Looking at lots of buildup on the butterfly valves here. carb cleaner and a toothbrush to clean it up? Should I worry about how much I spray on?

Kneale Brownson

It needs the lubricating properties of throttle body cleaner. You can use carb cleaner, but you need to add the throttle body cleaner after, so you might just as well use that from the start.

spitanddirt

I'm not saying your wrong but I've never heard of any kind "lubricating qualities" that are inherent in throttle body cleaner verses carb cleaner. Maybe I need to check more manufacturers MSDS, but as far as I know carb cleaner and throttle body cleaner are identical products in differently labled cans for marketing purposes.

See for yourself, here are a couple of MSDS from the ITW family of companies who make the GUMOUT line of products. If you notice, both the Carb and Choke Cleaner AND the "Professional" Air Intake and Throttle Body Cleaner contain exactly the same ingredients: Acetone, Toluene, and Carbon Dioxide....in exactly the same proportions!

http://itwgb.com/pdf/msds/gumOut/Gum...0US-ITW-GB.pdf

http://itwgb.com/pdf/msds/gumOut/Gum...0US-ITW-GB.pdf

As for actual use of the product, I never use anything except blue shop towels and a old plastic toothbrush to get the job done. NO wire brushes,
NO sandpaper, and NO other forms of abrasives. Spray, scrub, wipe....that's all there is to it. I wouldn't be trying to flood the engine or anything, only use what is neccesary to get the gunk removed. No need to flood the engine on startup.

pocketchange

After running a scope down through the TB (ugh!), I did the spray procedure and had another look.

Surprise.. it cleaned up a good portion of the upper plenum crud.

Ran it for a few days and repeated the procedure. Cleaned up nicely.

Still doesn't idle smoothly though!!!
Maybe one day I'll figure it out.
pc

gOOOOran

Dont know if this is good advice, I cleaned my maf once by leaving it overnight in a plastic bag filled with isopropyl alcohol (spray can from a electronics shop). Then the next time I decided it may be good to try something slightly abrasive, so I ripped a small bundle of hairs out of a circuit board cleaning brush (bundle of fibreglass hairs). I gently rubbed the metal element with this whilst soaked in isopropyl. I since had to get a new maf for other reasons, havent cleaned the new maf, and it reads less than the cleaned old maf used to read at 7000 rpm.
I have also seen a maf that was used with a K&N filter, it was so dirty the metal element was not shiny it was a dark grey colour.

silverd2

Wasn't gonna comment on this thread at all, for a couple of reasons...but now I feel the need to for a couple of reasons

Cleaning throttle bodies that need it...good thing...regain precise proper flow at throttle "closed" position and better internal aerodynamics (proven through polished ports, intakes. etc...for many years now), improving total air flow by cutting down on turbulence (resulting in less restriction..therefore more total flow) ...ALL great.

Cleaning MAF's?...IMHO, a bit absurd and grasping at straws...not gonna gain anything and risk doing damage to a very delicate part, that by nature is going to wear out eventually anyway (repeated super-heating and cooling of the wire, esp NOT in a vacuum, changes it's composition over time..clean or not). It's monitored precisely in newer cars and if failing your gonna get a code, stalling, etc...and cleaning AIN'T gonna fix that...replacing it will. MAF's are the most self cleaning and maintenance free components in the intake system and the best design in the evolution of automotive air volume measurement...ever since the earliest usage of the idea in the last "LH Jetronic" systems (the "H" denoting "HOT" wire sensor, instead of cruder mechanical measurement in other models...LH was used in my 89 P928, which at 160K miles had the original "hot wire" component, after using nothing but K&N air filters since the 60K mile mark when I bought it...it had a K&N in it when I bought it, too. Then "Motronic" systems took over, with "hot wire" MAF's.

Many who worry that their MAF's are changing the way their motor runs should be more worried about the primary 02 sensors...code or no code, if you have about 80K miles or more on them, they are NOT reading correctly and have much more to do with precise fuel/mixture adjustment than does the MAF. The MAF simply estimates the mass (therefore total volume) of the air entering the system. The primary 02 sensors read the result of that estimate and other "decisions" by how well and precisely the resulting fuel/air mix is being burned, then make the important and precise adjustments that make a difference. O2 sensors are not just anti-pollution devices...that's just a bonus added to their performance/efficiency purpose.
Believe me, changing your front 02 sensors on a high mileage motor will produce results that will blow you away...smoothest the motor has run in years, improved gas mileage, smooth powerful acceleration, better idle..."better" that is easily noticeable.

By the way, regular treatment with Techron fuel injector cleaner (the best real world results I've found to date) or similar high-quality product is a great "smoothing" idea also.

My D2's MAF was changed by the dealer under my CPO warranty at about 40K miles because they "said" it needed to be ($$$ that Audi corp would reimburse them for)...NO change, better or worse...all talk. Almost 75K miles later, my MAF works perfectly, looks brand new, surgically clean...and interestingly, I have used nothing but the same K&N filter since I bought the car at 36K miles (now 113.5K miles)...cleaned and re-oiled occasionally.

There have been completely unfounded fairy tales out there about K&N filters for years...simply because they are proven to be much more free flowing than stock paper filters, it is falsely assumed that they MUST let in more contaminates....this assumption has been proven wrong repeatedly, with real tests..not just what someone said. There have been cases where they were improperly installed (not seated properly by unqualified DIYer's) and allowed unfiltered air around the edges.
K&N's work beautifully, I've used them on every car I've owned ever since I've heard of them...a total of many 100's of thousands of miles...the result is perfectly clean intake air and proven higher peak horsepower over restrictive paper filters...NOT dirtier air, just better design for less restriction without cleaning compromise.