fiber glass in air filter & mass air flow sensor

[DanielinTheLions]

I was on a road trip this month in my 01 chevy prism and the check engine light came on. The car was running well and the gas mileage was normal so I finished the trip. Then after getting home I took it in to see our mechanic to get the code read . The car was reporting a "too lean" condition; we drove it around the loop near the shop and the car was reporting that it was needing to add 20% more fuel than it thought it should in order to get the correct readings from the oxygen sensor. We looked it up and this condition is usually caused by problems in the vacuum system or with the mass air flow sensor. After inspecting both we found that the mass air flow sensor had some build up on it. We clean the sensor, cleared the code, and everything seems to be back to normal. I've even taken another long road trip since and no problem.

He told me that it's most likely caused by the fiber glass in the air filter. He said he's had them come in with the sensor coated in fiber glass which of course inhibits it's ability to sense the air flow properly. He pointed out that while he wasn't sure about the stp filter I currently have in the car that fram air filters are the worst for this problem and recommended using a Hastings filter.

Thoughts?

 

[yonyon]

If you had glass on your MAF it would look like a fluffy ball of fibers. Did it look like a fluff ball or a dark colored coating?

 

[DanielinTheLions]

I'd say it was a bit of both. It wasn't a very thick coating at all but it was kinda dark with some whitish stuff all through it.

 

[bigjl]

Build up of contaminants on the MAF is an issue on a lot of cars these days.

I cleaned the one in my Mondeo with some carb cleaner and very light use of some cotton buds.

It wasn't bad, some black stuff came off, don't know what it was.

I don't think you can ever stop it due to the job the MAD sensor does.

Just add it to things to do every year or so.

Would you now consider cleaning the sensor every year as a bit of preventative maintenance?

It probably wasn't just the air filter but rather just build up due to use.

No air filter no matter how good is going to stop everything, too many joints to make the air intake system completely sealed. So a small amount of contamination will always be present, just my opinion.

 

[circuitsmith]

11-12 years and 100k miles to foul a MAF sensor isn't remarkable IMHO.
I would clean it every 5 years going forward.
It's probably time to clean the throttle body too.

 

[Jim Allen]

Fiberglass MAF contamination is a new one to me. I'm going to look into that one.

I wonder if he wasn't mistaking fiberglass for silicon? Silicon is the big killer and often comes from the MAF itself, migrating from the place where the sensor wire is potted and sealed from the circuit board... or built in from an improperly manufactured MAF. If you look at microsopic view so the FAF wire, the silicon looks kinda fibrous.

You can tell a synthetic media filter because it will usually be white in color (new) and look poofy and fuzzy (how's them for technical terms?) vs more smooth and formed for a cellulose media, plus more yellow/gold in color.

 

[accent2012]

Fiberglass? Are they trying to keep the intake insulated? ;-)