How much wear during warm-up?

[Scout1]

I understand that the majority of engine wear takes place immediately after cold start-up before the oil circulates under pressure to the engine. But after that, before the oil reaches normal operating temperature, how much wear happens then? My pappy always told me to warm it up and drive it easy till warmed up...

During the 10 miles or so, plus or minus it takes to warm the engine oil up to temp, it's a lot thicker and therefore doesn't circulate as rapidly. Thick oil in the bearings doesn't necessarily sound like a bad thing from a wear protection standpoint.

So should I run it easy or just drive normally? Is it a problem to run it hard during this warm-up period?

 

[salvageyardteen]

If your using the right viscosity oil and your oil pump is working you shouldn't need to warm it up. If you are really worried, you can buy a pre-oiler.

 

[Scout1]

A pre-oiler only circulates oil prior to start-up, right? That's not my question... I want to know if I should baby my engine till the oil heats up.

 

[JAG]

This subject has been covered well in past threads. Frigid start ups aside, wear rates are high prior to full operating temperature because of reasons other than oil viscosity and flow rates. It's apparently a chemistry matter where the chemistry improves with increasing oil and engine temps. "Chemistry" meaning additive chemistry and chemistry of fuel combustion.

 

[Big Jim]

Today's engines with today's oils just don't wear as quickly as they used to.

After a cold start you don't need to sit and let the engine warm up. Only wait long enough for the engine to stabilize. That may be immediately, but shouldn't be more than 30 seconds. Then drive sanely for a half mile to a mile or so. After that you can drive insanely if you are so inclined without worrying about excessive engine wear.

Best still, only drive insanely on a closed track with no other cars present.

 

[Eddie]

Yes. I drive easy until the water temp gauge reads normal. Oil temperature on my vehicle that had oil temp guages demonstrated that oil temperature lagged water temp by about 100%. So if it takes 5 miles for water temp to normalize then the oil temp with stablyize in aboyt 10 miles. The thermostate controles water temp to ~200F. but, oil temp can vary from 150 to 250 F in normal driving and is load & time dependent.

 

[glxpassat]

That's what I like about VW's water based oil cooler. It not only keeps the oil cool, but heats it up fast as well.

 

[Camu Mahubah]

I usually take it easy for the first mile or two...especially in Winter time...I always try to get the engine up to operating temp before I shut her down...I have owned so many "junkers" that make terrrible noises at start-up that don't calm down until warmed up...you know piston-slap and lifters rattling...perhaps this is why I baby my cars after an intial start... especially the first start of the day...By the way my last UOA had low wear metals...

 

[salvageyardteen]

Just drive with common sense and don't worry about it.

 

[aquariuscsm]

My 3000GT`s owner`s manual said to idle the engine until the temp guage started to move,then drive.

 

[Triple_Se7en]

Quote:

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How much wear during warm-up?

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Not enough wear to lose sleep over - inside 250K of your odometer - on any typical gas engine that's been OCI'd routinely/properly.

 

[AEHaas]

It takes up to 30 minutes to get the motor oil up to operating temperature. It is only at that temperature of the oil that wear stabilizes. Here are references to the research articles that show this important concept:

http://theoildrop.server101.com/forums/s...ge=0#Post918907

http://ferrarichat.com/forum/faq.php?faq=haas_articles#faq_research_paper_reviews

Another thing worth reading are my articles:
http://ferrarichat.com/forum/faq.php?faq=new_faq_item#faq_haas_articles

aehaas

 

[G-MAN]

Quote:

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It takes up to 30 minutes to get the motor oil up to operating temperature. It is only at that temperature of the oil that wear stabilizes.

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And the key point that everyone needs to get a grip on is that 99% of the wear metals we see in UOAs are the result of wear that takes place during start up and the following 30 minutes. A properly tuned engine running on good oil sees virtually NO WEAR once the oil gets up to operating temp (unless we're talking about the Audi RS4).

 

[pbm]

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That's what I like about VW's water based oil cooler. It not only keeps the oil cool, but heats it up fast as well.

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Maybe that is why VW's are so particular about which oil is used.

I agree with your dad about driving gently until warmed up but 10 miles is a bit too long. I'd wait till the temp gauge showed the coolant to be warm (usually a couple of minutes) and then drive normally.

 

[AEHaas]

"I agree with your dad about driving gently until warmed up but 10 miles is a bit too long. I'd wait till the temp gauge showed the coolant to be warm (usually a couple of minutes) and then drive normally. "

You need to drive a car with both a water and oil temperature gauge. You will find that water heats up in just a few minutes, sometimes in only 2 - 3 minutes. The same car will show 20 to 30 minutes to get the oil up to 180 F or more. It takes MUCH LONGER.

Read the articles above then one does not need to guess.

aehaas

 

[ssj4]

heh, I guess I have always been in the severe severe category. For the past 10 years, the majority of my trips have been 12 miles or less.

 

[G-MAN]

Quote:

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You need to drive a car with both a water and oil temperature gauge. You will find that water heats up in just a few minutes, sometimes in only 2 - 3 minutes. The same car will show 20 to 30 minutes to get the oil up to 180 F or more. It takes MUCH LONGER.

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What about on a car (like my 300M) that has a water-to-oil oil cooler in the radiator? Isn't this going to have the effect of getting the oil up to temp faster than it otherwise would by virtue of the hot coolant in the radiator warming the oil?

 

[moribundman]

Even if the oil gets up to operating temperature in x-minutes, it takes longer than that for the engine to heat up thoroughly. BMW used to say that process took 45 minutes of driving at highway speed.

Keep in mind that metal expands with increasing temperature. The oil me be at operating temperature, but the metal may still be expanding.

I drive gently until the oil temperature reaches 175°F. That process takes about 20 minutes.

 

[mechtech2]

Those tests [post 918917] have an unproven premise in that they selected the 'best' isolated area of an engine to test. It depends on the engine design. Pick another engine, and get different results.
Then they artificially set up an impossible situation, in which the oil and coolant are cold, and the engine parts are hot.

They go on to say that there is no wear difference from 0-10 to 10-40 oils.

Their methods and reasoning are not good enough for me, although they have very expensive equipment and resources.

 

[G-MAN]

BMW's variable tachometer is a good indicator of what should be considered the safe operating parameters of a cold engine. I believe the yellow-line begins at 4000 rpm for a stone cold engine (with the redline at 4500 rpm). The PCM monitors oil temp and as the oil temp rises so does the redline in 500 rpm increments until the oil is up to normal operating temps and the redline is at the max rated for the engine.