Question About Start-Up Wear

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Many people theorize that start-up wear accounts for a HUGE percentage of engine wear and I was just wondering: How much LESS SEVERE is start-up wear if the oil is at/near operating temperatures? (For example, driving to the grocery store, parking and starting it up 20 minutes later.)
 
Very good point...
By the same token, would there be any advantage to running an electric oil heater yearround to keep the oil warmer during the first start of the day?
 
How much less severe would depend on the engine temp. after the 20 mins. Such as a MN. winter. Oil heater in the summer is an interesting point!
 
if you just take decent care of youre engine it ought to last a few hundred thousand at the minimum.
the ammount of energy spent heating oil and coolant when its not needed would probably pay for a engine rebuild after a few hundred thousand miles, so i doubt its worth it.

electricity isnt cheap, and this is espically true with heating elements.
 
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Many people theorize that start-up wear accounts for a HUGE percentage of engine wear and I was just wondering: How much LESS SEVERE is start-up wear if the oil is at/near operating temperatures? (For example, driving to the grocery store, parking and starting it up 20 minutes later.)




Chuck: Lots of stuff here. First, the often used "start up wear" is misused a bit by the oil companies. Start up is defined as not steady state. That's about 20 minutes in an engine's life (Lorne Green Alpo commercial). You're at accelerated wear for about that long. Now it's on a curve, and the rate that you establish your lubrication flow would surely alter the onset of wear ..and would probably (sensibly) alter the severity of it ..but let's not EVER get the impression you're grenading your engine by turning the key. Wear is unavoidable.

About oil temp: Now heat oil surely flows better than cold oil ..all other things being equal, but that in itself won't move you out of the accelerated/elevated wear state. It's is the engines "state of thermal saturation" that (typically, in non-exchanged engines) dictates oil temperature. That is, as your engine thermally saturates ..and the pistons and rings expand ...that btu throughput of the combustion process is then transferred to the oil. When this temp peaks/normalizes (again, in a non-exchanged engine) is when you're at "steady state" and are at virtually zero wear.

So, heating oil can help shorten the time it takes to establish pressure lubrication to the engine..but beyond that, it can't simulate 2000F+ combustion temps to expand those pistons. You're still going to experience that "start up" wear.
 
Just drive your car, its a car, if the engine fails it fails, just change the oil within resonable limits, perform all maintainence, and dont be hard on it and it'll last a long time. If it doesnt last a long time, rebuild or get a new car. Theres more important things to worry about in this life, I found out.
 
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Therefore, we should start the engine, put it in gear, then drive off. Therefore, the oil would heat up faster and shorten the wear time.....




Man, that would go against all the wives tales I have heard that recommend idling for a bit before driving. Do you have evidence that this is better for the engine than idling for a bit before leaving? Not trying to start an argument, just trying to educate myself.

Jon
 
Most engine wear occurs during the first 20 minuites of operation. Due to the time it takes to get the oil up to operating temp. Credit goes to AeeHaas documents
 
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Therefore, we should start the engine, put it in gear, then drive off. Therefore, the oil would heat up faster and shorten the wear time.....




Man, that would go against all the wives tales I have heard that recommend idling for a bit before driving. Do you have evidence that this is better for the engine than idling for a bit before leaving? Not trying to start an argument, just trying to educate myself.

Jon




Yep! I do, I do. Look at my uoa's in that forum. I am a start it up and go kinda guy.
 
I've come to start and go - that is if you start the engine buckle-up, and adjust whatever needs adjustment, and then I'm gently off. In the winter months, I start-up, crank the defroster, scrape any ice, and when things are clear enough I gently drive off. As the engine oil heats-up, I gradually take to a "whatever is necessary" kind of pace.

Temperature of the oil also plays a part in the effectiveness of the AW adds, but with ZDDP slowly being passed to possible elimination, I'm not sure as to how much it will play a factor in future additive packs ability to protect when the hydrodynamic film is breached.

Less "cold" operation, less blow-by and all the byproducts there contained (acids, fuel, water vapor, etc.), which serves to contaminate the oil in the crankcase, especially if there is fault with the operation of the PCV system.

Take care.
 
Most vehicles nowadays jump to about 1500 rpm at start up. I'm sure this is very helpful in getting the parts moving without oil fast. Helps with your break-in period for the life of your vehicle.
laugh.gif
 
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Most engine wear occurs during the first 20 minuites of operation. Due to the time it takes to get the oil up to operating temp. Credit goes to AeeHaas documents


How about the pistons aren't round , the clearances are changing as the engine warms up ,the a/f mixture is a bit richer etc. It is more than just the oil getting up to temperature.
 
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