Does prolonged engine idle on a slope cause engine damage? (buy, engines)

[Innovator831021]

Originally Posted by geos

10 or 20 minutes??? Where did she get this brilliant idea? Why bother turning it off at all? Subaru engines are 90° inclined. They seem to do ok.

10-15 minutes is a perfectly normal thing to do on a cold day, I don't understand why people think this is so outlandish. Engines consume minute amounts of fuel when idling. Doesn't matter what the layout of the engine is, they are all optimized for when the vehicle is on a 0° slope.

[Ticky909]

normal, but good? necessary?

[Innovator831021]

Originally Posted by Ticky909

normal, but good? necessary?

Yes, it is good. When you let your engine warm up all the components expand and get closer to that operating range. Engine components are given clearances with this expansion in mind so when your driving your car for extended periods of time everything is up to temp and operating ideally. This is why short trips through the life of a car are detrimental and why highway miles are the best. Necessary is a relative term to how much you care and how nice the vehicle is.

[wankel7]

So, I have a turbocharged rx7 that I put an oil temperature gauge on. The oil temp would not come anywhere near normal temprature until I put about 5 miles on it.

Coolant would come up to temperature first but oil would take much longer. And might not get up to normal temperature until you drive.

[Innovator831021]

Originally Posted by wankel7

So, I have a turbocharged rx7 that I put an oil temperature gauge on. The oil temp would not come anywhere near normal temprature until I put about 5 miles on it.

Coolant would come up to temperature first but oil would take much longer. And might not get up to normal temperature until you drive.

I have noticed similar instances on a few vehicles, one of the worst culprits of this are those little Isuzu diesel box trucks... in the winter your lucky if those things warm up at all, you have to idle the things so damn high to get everything to warm up and all the cylinders to fire. Although its pretty common for oil to take the longest to warm up considering coolant surrounds the cylinders so it gets warm quick and oil has to travel through narrow galleys through the block and then get mixed back in with cold pan oil.

[Tennesseestorm]

Well, personally, I would not let my cars idle for a long time on a slope, but I guess its OK if like others have mentioned, the oil level is full. I guess cars are designed to the point of being OK sloped up to the point before they tip over!

Well, in regards of how long I warm up my cars.. as a owner of several different cars, I normally have a different warm-up span for them.

For all of the cars- in the summer when its warm/hot out, I will let the car run for a minute or two, then take off, but keep the speeds at reasonable levels until the engine is warmed.

In the winter if its cold out (our average lows in the winter are in the 20s-30s range).

On my 88' Mercedes, I will let it warm up for about 5-7 minutes, or until I see the temperature gauge start to go up, then I will take off and gently drive (which I do at all times in this car anyway).

On my 91' Lexus, I will let it warm up for about 2-3 minutes, or until the "fast idle control" goes down, (where it idles at 1000 rpms, then goes down to about 650 rpms) which normally takes about 2-3 minutes if its in the 20s out. Then I will again gently drive until it warms up at least 1/2 between the lowest part of the temperature gauge and the normal mark. Once on the road, it warms up faster than when just setting and idling.

On my two older cars, (1973 Pontiac and 1972 Chevrolet), both of which are carburated cars, I will let them warm up for about 5-7 minutes if cold out. The Pontiac, despite being a carburated car is not at all cold natured, because I can usually get in it and take off and it will run fine, whereas some old cars will stumble and stall if not warmed up. My Chevy is very cold natured and needs to warm up almost fully before it runs well, but this car is currently coming out of restoration (in storage for years) and probably needs a carburator rebuild.

[geos]

Originally Posted by JTraik

10-15 minutes is a perfectly normal thing to do on a cold day, I don't understand why people think this is so outlandish. Engines consume minute amounts of fuel when idling. Doesn't matter what the layout of the engine is, they are all optimized for when the vehicle is on a 0° slope.

Show me a shred of objective evidence. That may have been true 60 years ago but it's ancient myth today.

A typical idling engine consumes about a gallon an hour.

[Mugatu]

I'll join the side that thinks warming up a modern car is unnecessary. A car warms up to operating temp MUCH faster if you just drive it gently for the first few minutes. I don't think letting an ice cold engine sit there and idle for 20 minutes is any better for it, and it's a complete waste of energy.

Start the car, let the car idle for 30 seconds to a minute to get the oil flowing, then just drive it and the engine will be up to operating temp in just 5 minutes. Now of course, don't do any crazy jackrabbit starts or high revs until it is warmed up, but a few minutes of gentle driving to get the car up to temp isn't a bad thing. My car is 12 years old and still going strong, so I must be doing something right.

[Innovator831021]

Originally Posted by geos

Show me a shred of objective evidence. That may have been true 60 years ago but it's ancient myth today.

Ancient myth eh? Why don't you go read an engine manual and figure it out how things work under the hood if you don't believe what I have stated. I came to my own conclusions on engine care through teaching myself how all components of an engine work. I don't care about your engine, destroy it if you want, I am not going to waste my time proving the advice I have given if you choose to reject it. Best of luck.

However if you crave such a cursory explanation just go to a truck stop and ask some of the guys what are some of the things they do to keep their rigs going a million+ miles.

[Tennesseestorm]

Yeah, I never let my cars warm up to normal operating temperature. I normally let it run/idle until the thermostat opens up (which is usually when the temperature needle starts to go up). Then drive gently and the car them warms up pretty fast when on the road.