what wears an engine the most?

[edwardh1]

1. junk/dirt coming in with the intake air
2. combustion chamber by products
3. metal that comes off the wearing engine parts?

seems like dirt coming in with the intake air would be the worst, yet so much attention is given to oil filters not much to air filters.
what gives?

 

[Falken]

I think bar none it is startup wear from cold.

 

[eljefino]

Junk & dirt, and, you're right.

I respect the guys that put gooey grease around their filter seal for the "best seal".

I lift off the gas when I pass a street sweeper and its cloud of dust. Less to run through.

 

[bullwinkle]

#1, causing #3!

 

[Nate1979]

I'm going to guess that you are going to get a lot of guesses but it would be nice to see some documentation/proof instead.

 

[CT8]

1. junk/dirt coming in with the intake air. Not a guess.

 

[OneEyeJack]

Dirty air. It's something you can work on.

Forget start up wear. There's not much to do about it except in some cases, oil, block or coolant heaters and that leads to reducing warm up wear which by volume is more than start up wear.

Then there's bad fuel and dirty/poor quality/worn out/wrong spec oil and general operational abuse including short runs, lugging, overloading and over revving.

 

[440Magnum]

#1. Both air and oil filtration are important.

 

[PandaBear]

Cooling system malfunction. That'll warp the head pretty much instantly these days.

 

[wemay]

I always thought it was start-up/warm-up

 

[fdcg27]

#1 without a doubt.
Motor vehicle engines had air filters decades before oil filters became common standard equipment, especially with cheaper cars.
The cheapest spash-lubed OPE engine will have an air filter.
That's how vital they are to engine life.
The engine oil is formulated to deal with combustion products.
Metal wear particles after breakin aren't all that great in volume, which is the reason that an oil filter can go thousands of miles in service with only a few grams of holding capacity.

 

[901Memphis]

You are correct about there being a lot of attention to oil filter selection, when air filtration is far more important.

 

[HTSS_TR]

I had been saying for a long time that air filter is much more importance than oil filter.

I had been using prefilter for air many years, and clean/replace the prefilter without disturb the air box that can break the filter seal.

I had been using low to mid range oil filter for up to 20k miles in my LS400, the engine is running well after 370+k miles. But I only use OE air filter(or at least OE manufacture), because they are better construct than aftermarket low end air filter.

 

[oilpsi2high]

Cold starts and not changing fluids and filters when needed.

 

[Donald]

Contaminants in the oil, like coolant or fuel or MMO.

 

[Donald]

Originally Posted By: wemay
I always thought it was start-up/warm-up


Yes if everything else is perfect. But have an air filter with a tear and it will allow unfiltered air into the engine which is much worse than start-up.

 

[Rand]

unfiltered air by far, however not all OPE has a filter.. snowblowers don't for example.

 

[NMBurb02]

Originally Posted By: Donald
Contaminants in the oil, like coolant or fuel or MMO.

 

[NHGUY]

In the words of Slick 50 20 years ago "Starting your engine,is a terrible thing to do".They had the right idea,but in reality Teflon did nothing for startup wear.Its got to be tough on cylinders and rings starting a dry engine when the fuel mix is extra rich diluting the walls even further.

 

[Greasymechtech]

The owner!