oil and gas

Yuk

Messages
883
Location
Edmonton, AB Canada
It is often said that one of the worst side effects of idling a car is oil dilution from unburnt gas. How is it that idling allows more gas into the oil?
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
It's when you're idling it from a cold start mainly, because the mixture is richer and the engine takes longer to warm up so during this warmup time the rings don't seal as well so the fuel makes it past the rings and into the oil. I didn't even idle my car for very long this past winter (most of the time I'd just start and go but if the windows were badly fogged up I'd sometimes have to idle it a minute or two first) and I saw 1.0% fuel in my oil. In the warmer months I see 0.0% fuel in the oil.
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
Originally posted by jsharp: I do think the "idling with a too rich mixture" problem has been greatly reduced since the advent of modern EFI systems...
Not necessarily true. It's a lot better, but if you run a scan tool on your modern car during the warmup phase you can definitely see that the computer is dumping more fuel into the engine. It has to, you can't run too lean during warmup.
 
Messages
3,593
Location
Outside smalltown, IL
quote:
Originally posted by Patman:
quote:
Originally posted by jsharp: I do think the "idling with a too rich mixture" problem has been greatly reduced since the advent of modern EFI systems...
Not necessarily true. It's a lot better, but if you run a scan tool on your modern car during the warmup phase you can definitely see that the computer is dumping more fuel into the engine. It has to, you can't run too lean during warmup.

Agreed. I just think it's better now, not gone. You're right. It has to be rich or it wouldn't run...
 

MolaKule

Staff member
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21,600
Location
Iowegia - USA
quote:
I guess those erroneous statements are just fear mongering from Watermelons ( Environmentalist green on the outside, communist pink on the inside).....
[LOL!] [Big Grin]
 

Yuk

Thread starter
Messages
883
Location
Edmonton, AB Canada
I don't idle the car anyway (I hate wasting gas), but the statements I've heard are more general. Like, it doesn't matter whether the car is warm or cold, more gas is getting dumped into the oil while idling, then when under load. I guess those erroneous statements are just fear mongering from Watermelons ( Environmentalist green on the outside, communist pink on the inside)..... [Wink]
 
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