How is Idling bad to Oil?

[lexus114]

Originally Posted By: Gasbuggy
Originally Posted By: LeakySeals
My GF's dad lets his Sienna van idle for 30 minutes every morning. Drives me nutz.


you live with them?



hahaha

 

[0w10]

Originally Posted By: FordCapriDriver
Recently i watched a video from Regular Car Reviews of a review of a 2012 Chevy Caprice with an LS motor , it was a cop car, apparently the engine had over 2000 hours of just idling, apparently when the owner put a new more aggressive camshaft in it he found the original cam was very badly worn.
https://www.youtube.com/watch?v=LvynJKOdT4g he talks about it around the 3:00 minute mark.
An engine at idle operates in boundary lubrication, when driving at high speed on a highway an engine will be operating in a hydrodynamic regime, which equates to less wear ( in theory )


Hi. I just had to sign up to say something about that. What you are talking about has nothing to do with idling or oil. That wear is due to bad lifter and cam design on that engine (along with earlier 5.3L). The displacement on demand was added to the old 6.0l engine used in the caprice and prior in the G8. They all suffer the same issues; lifters fail, often pulling the threads in the head and starving the camshaft of oil in places causing all sorts of issues.

It's a bad design that GM decided to go with in order to get a few more MPGs to put on the paper. failure have been recorded in as little as 20000 miles and all of them will have suffered them to some degree by 80k. The solution is to essentially rebuild the engine removing the DOD components and recoding the ECM to disable said function. A costly measure.

Just wanted to make sure nobody thinks this is due to idling or oil

 

[jongies3]

Fuel dilution causes the oil to break down faster, engines run richer while idling. It's better to start up, let the car idle for about 30 seconds (maybe a minute or two on extremely cold mornings) and just drive down the road gently until the engine warms up. It'll warmup faster and waste less gas, saving you money. If the car is left idling extended periods at operating temperature, the engine will get hotter due to low airflow through the engine and this too can have an impact on the oil's life, especially if your engine has an older style clutch fan over electric fans that push air based on RPM speed.

 

[SteveSRT8]

Nonsense^^^

The above info is wildly platform specific.

We run vehicles in cleaning that idle all day, sometimes across two shifts. Per actual OBDII data the injector pulse gets so short at idle it is amazing that they still run. Not richer at all, MUCH leaner. Engine life here is always at least 200-250k miles and sometimes much longer.

And they all have clutch fans! Never get hot idling, actually fall below the thermostat temp even in Florida summer. Oil life is determined by the OLM and it even takes into account stationary operations like ours.

 

[BrocLuno]

A lot of this has to do with engine topology. Old flat tappet V-8's with marginal lifter heat treatment (mostly GM's) had issues with cams going flat. you need aprox 2,000 RPM to sling enough oil to really lube a cam in these engines.

OTOH, big rigs almost all have roller valve trains along with most more modern engines than cam-in-block (push rod) designs. they will happily idle for hours on end.

Fire trucks, Ambulances, Police Cars, some tractors, some pumps, will idle more than they run at RPM. They all seem to go well over 100,000 with a LOT of short tripping.

Big Rigs can go over 1,000,000 miles with extended idle times. It all depends on how good the fuel system is. Generally has nothing to do with oil ...

 

[KL31]

My car idles at 14.7:1 AFR after a very short period of warmup so this fuel dilution stuff seems unlikely unless you idle rich for some reason?

 

[Oregoonian]

Originally Posted By: jongies3
Fuel dilution causes the oil to break down faster, engines run richer while idling. It's better to start up, let the car idle for about 30 seconds (maybe a minute or two on extremely cold mornings) and just drive down the road gently until the engine warms up. It'll warmup faster and waste less gas, saving you money. If the car is left idling extended periods at operating temperature, the engine will get hotter due to low airflow through the engine and this too can have an impact on the oil's life, especially if your engine has an older style clutch fan over electric fans that push air based on RPM speed.

+1.....^^^ AGREE COMPLETLY ^^^

 

[FCD]

Originally Posted By: Oregoonian
Originally Posted By: jongies3
Fuel dilution causes the oil to break down faster, engines run richer while idling. It's better to start up, let the car idle for about 30 seconds (maybe a minute or two on extremely cold mornings) and just drive down the road gently until the engine warms up. It'll warmup faster and waste less gas, saving you money. If the car is left idling extended periods at operating temperature, the engine will get hotter due to low airflow through the engine and this too can have an impact on the oil's life, especially if your engine has an older style clutch fan over electric fans that push air based on RPM speed.

+1.....^^^ AGREE COMPLETLY ^^^

+2