TheShodan

iTrader: (14)

That wasn't your question, sir. I answered that directly.

You asked specifically:

My response was in answer to that part of your question. Not to comment on your overall generalization of your viewpoint, or to give a cost-benefit analysis of warming up the car..

It's important to stick to one premise of your question to one person please. I've taken the liberty of putting in the debate "breakdown"

TomCat39 = benefit analysis of car warm-up

2LEM1 = evidentiary support of a service manual showing that warming up a car for a short period of time has benefits or is a requirement

The Shodan = Generalized premise that the theory of planned obsolescence is a genuine factor in how service manuals will not state other "tips" or benefits for drivers/users in the ownership of their vehicles for reliability & longevity.

I'm sure that will help end any confusion.

holmesnmanny

​​​​​​​Whether you idle the car to warm it up or drive it, it's still warming up exactly the same way. There is nothing mechanically different in the process of warming up an engine. As any metal warms up it expands. This is why valves close as the car warms up. This is why you have to set the valve lash, to allow for the expansion of the metal. This is why engines are more noisy on startup because the valves are set at certain gaps which close as the engine warms up, which is why the manufacturers tell you it must be done on a completely cold motor, so it's exact.

This isn't rocket science. So, again, there is nothing different happening mechanically between someone warming up their car by idling it versus someone warming up their car by simply driving it. It's the same thing mechanically.

Furthermore, within a few seconds of startup oil is going to be pushing completely around the internals of the engine. It makes no difference whether the car is idling to temperature or driven to temperature at that point. No difference whatsoever.

If there is anything different from the op's car or his gf's car internally on a teardown there are numerous reasons why this could be, but one of the last reasons it could be is due to idling the car to warmup versus driving the car to warm up.

If you need any other lessons feel free to give me a holler.

pogeeboy27

iTrader: (3)

OP needs to post up pics and provide more evidence since he claims to have plenty of it.

TomCat39

This is totally inaccurate.

Loading the engine vs idling, mechanically the injectors or open longer. The force on the pistons and cylinder walls is greater. The force on the oil cushioned bearings is higher. The force on the piston rings is greater. The stress on the ring lands is higher. The pressure on the wrist pins is higher. Mechanically, there is nothing the same about loaded engine driving and idling even at operating temperature, let alone during cold or below operating temperature. And all of this is when the metal is not expanded to be in the engineers ideal specifications. Like you said, valve train is noisier cold, piston slap is a lot more apparent when cold and goes away once warm. Etc.. Etc..

Mechanically there is a LOT of differences between warming idling and warming by driving. There is also a time difference depending on just how cold it is outside. So the effects can be significantly prolonged by cold driving.

****, even the drag on the crank shaft and oil pump is greater when cold. The drag on the pistons will be a touch higher (harder to scrape off) and even the frictional drag on the cam shaft in it's journals is going to be greater. This means to get the same driving output, all stresses will be higher as well as fuel consumption will be higher.

Now when you can prove the force to push or pull an object through molasses at speed X and temperature X equals the force to push or pull that object through water at same exact speed and temperature.... And when you can prove the specific tolerances/specifications required by the engineering is exactly the same in the engine when cold and warm... Then, only then will I listen to your alleged "technology class" with any kind of credibility.

Until then, you are still only spouting empty opinions.

2LEM1

iTrader: (1)

holmesnmanny

lol Using your logic we shouldn't even be driving cars because it's going to put stress on the engine so that it wears. NO ******* DUH ITS GOING TO WEAR IF YOU DRIVE IT. Thanks for that, Captain Obvious. lol

​​​​​​However this doesn't mean that you need to idle a car to warm it up versus driving it to warm it up.

As I said before, the engine is going to be lubricated in full when the thing cranks around for the first time, even before the engine has started. That's the job of the oil pump.

This is all common sense but it sounds like common sense is overrated to some people.

holmesnmanny

It doesn't sound like you realize the tolerances on a cold engine are a lot greater than on a hot engine so it's going to wear greater when the engine is warmed up than when the engine is cold anyhow.

2LEM1

iTrader: (1)

Ummmmmm

TheShodan

iTrader: (14)

You may want to check that textbook you're using in that technology class, friend. You sure you didn't miss out on a metallurgy class somewhere down the line here?

holmesnmanny

Sounds like you just threw in the towel and that's totally cool.

Caoboy

Tolerances eh?

Can you expound on how tolerances would change between a cold and hot engine?

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TomCat39

I personally am only throwing in the towel as you can only lead the donkey to water, you can't make it drink. Aka, you can't reason with the unreasonable.

I already pointed out the huge flaw in your thinking with piston slap. Piston slap is a lot more wear than non piston slap conditions.... And piston slap happens when cold, and goes away once the metal begins warming up. The wear also reduces. If you reduce pressures and frictions, wear reduces.

But like I said, you can lead a donkey to water, you just can't make it drink.

Think about this one, what happens to brake friction when it gets hot aka brake fade? Now I suppose you are going to claim friction has no effect on wear.......

holmesnmanny

​​​​​​​You're not aware that metal(or anything for that matter) expands as it heats up ?

holmesnmanny

There you are again trying to change the ******* subject. It's really sad you gotta keep resorting to this because all your arguments have completely been dismantled by me.

This discussion has nothing to do with normal engine wear. All engines, when running will wear to some extent. This is normal. This is because of friction.

However the point of discussion, YET AGAIN, is "Warming up your Honda before driving, necessary or waste?" not "does your engine wear?"

As I stated already, and this is common knowledge, the oil pump is going to push oil around the engine within seconds of the car cranking, most likely before the car has even started so whether or not the car needs to warmed up is irrelevant in that particular case because it happens before you have a chance to either idle it or drive it to warm up.

Furthermore, I even did a quick google to see if anyone else on the internet has ever even debated this and this is what I found...

https://www.google.com/search?q=do+you+need+to+let+a+car+warmup+before+dr iving+it&oq=do+you+need+to+let+a+car+warmup+before +driving+it&aqs=chrome..69i57.7135j0j4&sourceid=ch rome&ie=UTF-8

I see literally 0 threads where people stated definitively that you need to warm your car up. So clearly you and the OP, and your buddies that keep chiming in but can't even defend your argument that you need to idle the car to get it up to temperature before driving it, are smarter than the Honda engineers that designed the cars, smarter than ANY automotive engineer that designed the cars because no automaker in recorded history that has produced a fuel injected car has EVER stated you need to idle a car to warm it up to temperature before driving it, smarter than everyone else in recorded history that has said you don't need to do this, or you're just flat wrong.

I'm pretty sure it's because are just plain wrong.

Caoboy

​​​​​​​so how do you check to see if you are within tolerance on a cold engine, versus a hot engine?

TomCat39

If you go so narrow minded as to only read the title and not the OP's first paragraph where the discussion resides.... Then you would be correct.

This expanding sentence (in the very first paragraph) is discussing extra wear. Wear is harm on the engine. Reducing wear is the desired action to preserve the engine aka reducing the harm on an engine.

If it's not then oil wouldn't be of concern, we'd just have to swap engines a lot more frequently. As all engines wear and it's of no concern, says you, there is no need to discuss it, think about it, research it or even experiment with it. Is this your message?

We haven't even broached the typical driving habits of the start up and go drivers. It sure is not babied until warm.

So yes, this conversation is predominately about wear and the debate of cold versus warm driving plays a role in reducing or increasing wear.

Imagine that.

Then again, I've actually read the first post to know what the conversation was about.

TheShodan

iTrader: (14)

That's NOT what you're saying here, home-slice. Please Re-read your original statement correctly.

To stay in a respectful manner, I'm going to concede and say that I think you're right. I'm going to throw in the towel. I'm going to just let life teach...I wish you luck in your the application of your reasoning.

TomCat39

Oh, and I better define "Harm" so it can't be twisted into something it is not.

For our purposes the most simplified definition is:

Harm is ANYTHING that will cause the engine to fail.

holmesnmanny

​​​​​​​Why would you need to check it ?

holmesnmanny

Since you have a problem reading, I'm going to give you the cliff notes on the entirety of the OP's first post. The entire first post is about the OP tearing apart his motor and checking for wear after apparently only having differences in how the car was warmed up, his being done after idling it, and his gf's being warmed up simply by driving it.

So the subject matter is whether or not idling the car to warm up produces less wear overall than driving the car to warm up. Whether or not we agree with his "evidence" is irrelevant within our particular discussion at this point in the thread since I'm pointing out simply what the subject matter is.

You lose.

TheShodan

iTrader: (14)

holmesnmanny

Yes, that's probably a very accurate representation of how you're feeling right now. And rightly so.

TomCat39

What ever floats your boat dood.

pogeeboy27

iTrader: (3)

We're all adults here right? Can we all agree that the above statement by the OP is what we are trying to discuss here and not wasting gas by idling? A car's warmup routine affects many things but let's keep it on topic by discussing one thing: engine wear.

Caoboy

for one, tolerance is a range, there is no more or less, it's a set range of numbers.

You're thinking clearance. You have more clearance on a cold engine due to the metals being contracted. At operating temperature you have less clearance due to the metals being expanded.

It's also why we have to use certain weights of oil, so it's thicker when cold, and when warm is thinner.

If you were out of tolerance you'd have either too large or small of a bearing clearance and it'd either tighten up too much and seize the motor, or it'd be too loose and you'd spin a bearing or throw a rod.


Idk what I'm talking about though, I'm just a sheet metal fabricator.

What is it you do again?


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