Engine air filter - wash it out?

I have not done this with the engine air filter but washed my cabin air filter when I could not find a replacement and the dealership was closed for the weekend.

After washing gently and drying in the sunlight, it was like new again. I used it for another few months before finding a replacement. It still looked in good shape when I replaced it.

Others on here have said they have washed and reused the cabin air filter. I do not know why you could not do this with the engine air filter.

 

The cabin air filter appears to be made of a plastic weave, so it will tolerate washing (although its effectiveness may be reduced.) If you allow use of a substandard filter the air conditioning system potentially is at risk since the system was designed for filtered air.

The engine air filter is made of paper and not intended to be washed and reused. Use of a substandard filter may result in excessive engine wear, if fine dirt can get into the combustion chambers, causing excessive piston and cylinder abrasion. You'll have to decide whether saving $15 for a new engine air filter at 30K mile intervals is worth taking that risk.

 

It would be interesting to have it tested for efficiency and strength. I would not chance it in your Prius. Would be very expensive if it did not do the job. I have read that filters are more effective with age and that we tend to replace them too often ? H

 

I would think small particles are now on the engine side of the filter you cant see. These will now fall off and be sucked into the engine. It is the microscopic hard inorganic stuff that produces wear and scratching.

Bob

 

This is a classic example of false economy.

 

That's a bad idea. The engine is far more sensitive to dirt in the air than you are.

As previously mentioned, washing it can cause dirt to get on the clean side of the filter and you have no idea what washing it does to the micro porosity of the filter media.

Most knowledgeable people will even tell you to not try to clean it by blowing it clean with compressed air. The filter media is specially made to pass air with low resistance yet catch very small dirt particles. It doesn't take much top make it less effective.

 

The Owners Manual for our 2010 suggests for the Cabin filter that you can inspect it and if it's not too dirty just blow compressed air through from the clean side. It makes no mention of cleaning the engine air filter though. K&N might make a filter that you can clean and re-lube. I've used that kind on a motorcycle once.

Considering the long replacement interval, and what's at stake, I'd just replace the engine air filter.

 

I like the 2010's oil filter: only the paper element and (I believe) a rubber ring are replaced: the housing is re-used. Is that the case with earlier models?

 

Classic and 2G Prius have a different gasoline engine, which uses the traditional oil filter with a stamped steel disposable shell. It is true that the 2010's filter is less wasteful since that car's engine has a permanent oil filter housing that is not replaced. However there were many complaints when the 2010 engine design became known, from group members who were not comfortable with the idea of having to remove and replace the cap on the housing.

[My 1992 MBZ 400E (32 valve, 4.2L V8) also had a paper element oil filter that lived in a permanent housing. This is not a new concept.]

 

Oh yeah: when I was a kid in the 1950's, our local gas station had a nightmare out back: all the used oil just got dumped, and there were a lot of the paper filter elemnents strewn around.

I heard one issue with the 2010's filter: you can screw up the o-ring location. It would be nice if Toyota would include oil & filter instruction, specific for model years, in the Owners Manual...

 

They were common in the 1940s. Spin-on filters didn't show up on mainstream cars until 1957 (Ford and Chysler corps), GM was slower.