Someone Explain this Winter idle (Searched)

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quote:

Originally posted by Al:

quote:

Originally posted by Patman:
The engine is only being run for about a minute tops.

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How about moving the baby seat to the Firebird.
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Don't tell me how hard it is I have 3 grandkids
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It's just easier to use her Honda though, since it's a four door. Convincing my wife to start using the Firebird for our shopping trips, dinner outings, etc. would be nearly impossible. She just wouldn't want to be trying to put the baby in the back of any 2 door car. And like Tom said, we also like having the baby get into a warmer car too.

So am I really introducing much moisture by running it for that very short time? Or would more of the moisture be created once the coolant temp starts going above 100F? I would imagine in just one minute and that short drive, that the coolant temp barely moves more than 10-15F from where it was. So maybe this isn't enough to create condensation yet?
 
quote:

Originally posted by PontTransAm1978:
See... I dont think that alot of people know about how your not supposed to Idle your car.

It's one thing to idle it in 0F weather but what really bugs me is when people get into the habit during the winter but then carry the habit into early spring. I worked with a lady who would go out to her car about 20min before quitting time and start it up. But even in March when it was 50-60F out, she'd still do it! What a waste of fuel! And she drove a Honda, which starts giving heat in 2-3min of driving anyways.
 
So, Does anyone know exactly how much damage is being done? What I got from this, is the fact that the oil is being dilluted with water and Fuel, and this normally happens. And at operating temp, it evaporates... So, this stuff is going to evaporate eventually, and how much damage could it possibly do in the time you are idling?
Just a Thought
 
78Pontiac, there are different ways of looking at it, IMO. First would be that a vehicle that doesn't have to undergo cold starts for the number of miles accumulated -- traveling salesman versus retired grandmother -- is less likely to have cold start engine wear.

Second, to conduct a test that covers far too many variables of starting keeps even general rules a little vague. I recently had a look at a 1973 Chrysler Master Service Technician Bulletin on starting. The "rule' was that the longer it sat, the harder it would be to start -- lean fuel mixture, mainly -- and that waiting 15-20 seconds for the engine operation to stabilize was adequate before kicking off the fast idle prior to putting the car in gear. Yet these "rules" don't apply so easily in cars with modern batteries, EFI, better construction, etc.

Third, I think the list you have is more than comprehensive. The hard part in my experience is in keeping to it winter & summer, for all situations. Many of don't drive a morning commute anymore -- could be going off in a hundred different directions -- and establishing a "wear pattern" is one of the keys to good maintenance.

I believe that, on an used car, it takes a new owner about 10,000 miles to re-set the mechanical relationships to his pattern. For good or bad.

Consistency is the name of the game. And keeping careful records -- especially trying to note patterns over 30-40,000 mile intervals -- to keep maintenance expenses at an optimum level is the bigger picture here.

A book you may enjoy is:

DRIVE IT FOREVER: "Your guide to long automobile life"; by Robert Sikorsky.

He does a fine job, at length, in covering this subject.

On my 32-year old Chrysler, I leave the house, drive 5-miles thru city streets, hit the freeway and cover 25-30 miles prior to running errands, what-have-you, if it hasn't been driven in a while. It's a "warm" motor the rest of the day.
At least once a month it goes for a 100-mile easy drive. That has worked for me on a number of cars which have gone 150-250,000 miles in daily service.
 
4. When Idling, you have the lowest Oil Pressure, which means that bearings in the engine are not getting the protection they need. Also, low pressure is going to make it even harder to move the cold oil

5. Just letting the engine Warm up, does nothing for the rest of the car. I.E., Transmission, Differentials, Transfer Cases (if you have one), ect.. The rest of the fluids are still cold. So, driving normally with a warm engine, and cold fluids other wise is bad.



In all due respect I cry BLOODY CROW to the misbelief-assertions in line 4-5.

Based on 4....this aspect is based on the engineering of the Engine. GM 3800 Series Engines have an idle oil pressure reading of 60psi on average. If you rev the engine even to redline the 60pise value does not change significantly.

On a cold start of an ambient air temperature of 19F as observed last night on start-up the engine oil pressure reading I observed was 70psi! That is no where near low!

I have no fear in the Oil Filter blowing out...but i rather warm the car to lower this value.

On line 5: The Transmission to contrare does warm up with the Engine...again depending on the car engineering. My assupmtion is two-fold; 1st your that your car has a integral Transmission ATF cooler integral to the Radiator. Hence; as Water Temperature increases so will the ATF accordingly!
Second, the rotation of the Torque convertor and frictions generated by the transmission even in idle will further "heat" the ATF.


There is more than idling your engine than that.

Again, perhaps the most conclusive answer would be to run an oil analysis test by using both behaviors. Variable 1 would be 1-minute idle for the intial test over a certain mileage...and conversely the next oil change would be with a longer warm up.
 
1] Prolonged idle before the car reaches operating temperatures in fluids/greases/tires.

2] Minimizing the period of warm-up.

3] Driving during warm-up to keep wearing surfaces/gaskets/seals safe.

Granted, modern cars and materials have eliminated many of the problems seen once; and with the advent of EFI, even more so.

What is operating temperature? The point where all is working to design, minimizing wear to its lowest point. An old rule of thumb is that a cold start is the equivalent of a 500-mile drive so far as wear is concerned.

Transmission oil and engine oil do not reach operating temperature as quickly as engine coolant. Some auto transmissions do not circulate very much fluid at all when in Park. Manual transmissions not at all.

They, like drive axles, wheel bearings, suspension, steering components and tires are dependent on the movement of the vehicle and take a fair amount of time/distance to reach the point where any moisture/contaminants are being burned off rather than accumulated.

As to low pressure at idle, when in Drive, at a stop, the pressure is lower across the bearings than in other driving situations. The pump rotates according to engine speed.

The engine is under load -- being absorbed by the torque convertor -- and the pressure reading across the main and rod bearings is the lowest the engine will see. The hydrodynamic wedge isn't as well-formed as it well be when op temp is reached. Fully warmed oil flows "better". Thus the desire of many for synthetics that flow extremely well even cold. When the oil is overheated, too thin is even worse (shearing). Accelerating fast away from a stop with a cold engine is a classic hard wear situation.

And, as oil filters do not remove unburned fuel, water or acids, making the attempt to minimize their formation is obviously a good idea. They neither lubricate nor protect components, just the opposite.

Ever taken a car out for the first highway drive in a good while and found the oil low at the first fuel stop? Topped off, drove, and it didn't change after that? Engine was finally able to burn off the water/gasoline and other contaminants in the oil.

Engines (and other drivetrain components) work best within a prescribed temperature range. Reaching that range quickly, evenly -- and not overshooting it with temperature spikes -- means longest engine/component life.
 
quote:

Originally posted by TheTanSedan:
...Some auto transmissions do not circulate very much fluid at all when in Park. Manual transmissions not at all...

Actually if the clutch is out in neutral the only thing not turning is the output shaft. The input shaft, layshaft and all the gears will be turning. So the fluid is being circulated same as if it was being driven, albeit at a very low speed and little load, so your point is still probably correct. I doubt a lot of heat will be built up. Although on mine it seems it is enough in extremely cold weather to help those first couple shifts, since I am running dino oil now.
It is so thick when cold, engaging the clutch in neutral drops the engine a few hundred rpm until the ecu can adjust. Likewise releasing it will raise the rpm.
 
In the winter I let my Dodge diesel idle till it is warm. I have a high idle device that ramps the idle up to 1500 rpm. I have been doing this for several years and have never had a bad oil analysis doing so.
 
Notice any modern fuel injected gasoline engine. The computer will put it at a high 1500-2000 RPM idle when cold. What's more, the mixture will probably controlled well enough that the minimum amount of fuel is being used to maintain combustion.

The days of an over-rich automatic choke dumping tons of raw gas into the engine are gone. It went the way of straight 30 weight...
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[ January 21, 2003, 10:24 PM: Message edited by: jsharp ]
 
quote:

Condensation will appear in the oil as a result of combustion byproducts.

I was always under the impression that the majority of moisture that formed in "not warmed up enough" engines was simply because you heat the interior of the engine (granted NOT enough to evaporate accumulated moisture) ..this engine cools ..drawing in (through various configured vents (PCV, beather, whatever) MORE MOIST AIR. Repeat cycle = milkshake = emmulsified oil/water mix.

This is the first time I've ever heard that the minute blow-by gasses were primarily responsible for this problem.

Oh ..btw- I'm a 30-45 second idler before driving. But I've got a newer Jeep ..the 4.0 warms in about .5 -.75 miles to operating temp. My 2.5 TJ takes a little longer ..maybe a mile.

[ January 22, 2003, 01:26 AM: Message edited by: Gary Allan ]
 
You are lucky Gary, it takes my 95 Firebird Formula at least 5 miles to get up to full operating temperature in the winter (when it's 20F or below) Even in the summer it still takes more than 3 miles. My wife's Honda, with it's tiny 3 or 4qt coolant capacity (this is not a misprint!) warms up very fast, within a mile in the summer, and within 2 in the winter, with no prior warmup.
 
Yes, the Jeep(s) do well ..I don't know why. They are much faster then my aluminum head 3.0 Mitsubishi in my Caravan ..which takes about 5 or 6 miles. I hope they didn't engineer some "acceptable design flaw" to get some CAFE or EPA type allowance because they put out fewer "warming up" emissions.
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Patman,
Have you renewed the thermostat in your car lately. An old 'stat can seem to work OK, short of failure, but be responsible for a sluggish warm up. Stant says that their "SuperStat" thermostats are designed for a faster warmup, also.


Ken
 
Ken, the thermostat was just replaced in November actually, when the dealer backflushed my heater core to fix a no-heat problem. The car puts out great heat now, it's just that with a large cooling system it takes longer to reach operating temp. This is my 3rd 4th generation Firebird I've owned and they are all the same, they take long to heat up.
 
Bigger the motor (and cooling capacity), the longer it takes. Just try to idle a 3406 Cat from stone cold to op temp. You'll be a long while waiting, even at high idle.

Of course EFI has changed the warm-up of modern cars. But last I knew 1978 Pontiacs still ran Quadrajets.

And diesel engines have always had fewer idle related problems than gasoline-fired engines: it helps that they are air, rather than fuel, limited; have no ignition, and generally are built to closer tolerances.

Even then, no one recommends prolonged idle. And other components need a little help to come up to temp in an even manner.

A little care the first few miles -- after a short idle period -- still works best. That is, if one intends to keep the vehicle to 150,000 miles or beyond. Consistency is all I would argue.
 
Just a thought...

Many engine designers now say the primary factor in engine wear is not the number of miles driven or the number of hours it is operated.

The primary factor is the amount of fuel run through the engine.

Maybe the way to increase engine life is to reduce the fuel consumed to as little as possible?
 
Makes sense, and may actually be true. But I think you are reading into it the wrong way. It's not the actual fuel that is causing the problem, it's the CONDITIONS that cause more fuel to be used. E.g. cold starts that cause engine to run rich (using more fuel), Running high rpms (using more fuel than lower rpm), lots of acceleration (using more fuel), etc...
 
I like the idea of fuel consumed as a point of departure. Works for engines old and new, when allied to time and miles. SEFI versus carb is antiquated as a beginning, irrelevant in too many cases. If more is known, more comments to flesh out what that statement means is available, please post.
 
Yea, on my way to school, my car never gets anywhere near Operating temp. Its barely above the lowest setting on the gauge, but seeing as how it starts out below the gauge... So, is that going to be really bad for the car? I dont hammer on it or anything, I just take it easy.
Thanks in Advance...
 
It doesn't matter...the car serves your needs. As you already say, don't hammer it, and change the oil frequently (3k) when you can't warm it fully frequently.


Ken
 
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