oops - too much oil added - help

[beagler]

I added about half a quart to my 06 Pilot when changing the oil. I ran it for about 190 miles before I realized my mistake. I drained it down to the appropriate level last night. Do you think I caused any damage?

[rocky]

nope

[2010exl]

No problem with 1/2 quart.

[theirishscion]

Agreed. 1/2 a quart, no damage. That should be well within tolerance.

[beagler]

Originally Posted by theirishscion

Agreed. 1/2 a quart, no damage. That should be well within tolerance.

Do you have any idea how much oil is too much? I'm just curious.

[94eg!]

You'll know when your engine starts smoking as soon as you drive it... lol

Yes I'm serious. Probably takes a couple quarts.

[theirishscion]

That's a good question. One to which I an only reply with opinions, not facts. Others may wish to weigh in on the topic as well.

The risks around overfilled oil all seem to come down to the spinning crank hitting the oil and frothing it up, assuming that the oil isn't so overfilled as to be cresting the crank bearing seals all the time, in which case it'll presumably start to leak out even when stationary. Frothed up oil doesn't pump well, leading to possible oil starvation in the head and elsewhere in the engine. I suspect this can also choke up the positive crankcase ventilation system, upping crankcase pressure and causing crank seals (and perhaps other gaskets) to leak or even blow out. The crank kicking the oil up against the bottom of the hot pistons might supposedly cause it to burn and carbonize as well, though whether this would be the case in the Pilot I don't know.

However, all of this presupposes that the oil level is high enough to catch the spinning crank. It's my sense that for a big-ish V6 engine, with associated big-ish sump, 1/2 a quart of extra oil is only going to raise the sump level a small fraction of an inch, and there's quite a bit of leeway engineered into the system to allow for driving on hilly train and sloshing during long high speed corners. I'd personally start to get a little concerned at a full quart over, though I bet it'd take quite a bit more than that to cause real damage. This is of course a good argument in favor of higher quality, anti-frothing engine oils, y'know, just in case. But then I'm a compulsive over-maintainer.

Considering you have already corrected the problem before any symptoms showed up, I'd say pretty categorically that you won't have done any damage. I'd actually be prepared to bet that you could have run the full 7500 miles with 1/2 a quart extra without doing any damage whatsoever.

Keep in mind also that the high school dropouts manning the air wrenches at the Qik-E-Lube-Stop-Wrench-Center couldn't give a rat's patootie about your exact oil level. If they manage to navigate the sump plug back in without cross-threading it and remember to screw on a new oil filter before you drive off, they're on target to make Employee of the Month(*). They overfill and underfill All The Damn Time, and you very very rarely hear about engine damage when they do, most manufacturers allow a lot of leeway (with some notable exceptions, VW/Audi is the first that springs to mind), usually the customer just comes back angry because their car's running funny and spewing engine oil all over the road from breather tubes, the shop drains off the excess, apologize and sends them on their way. No further harm done. Complete loss of engine oil is where you get the quick and catastrophic engine damage, usually the result of stripping out the sump plug (which quickly falls out after the customer leaves) or forgetting to put any oil at all in. Believe it or not, it's not that uncommon for them to drain the ATF and refill the engine oil, thereby adding 4.5qts extra engine oil and leaving the transmission empty. Now that's what I call overfilled!

(*) In reality, Employee of the Month (also commonly known as Continued Employment) is reserved for the urchin who up-sells the most expensive and unnecessary add-ons to poor trusting folks who don't know any better, then doesn't actually bother doing them. Just search Google Videos for 'jiffy lube scams' for details if you feel your blood pressure is dangerously low at the moment.

[1YESfan]

I have a Jeep mechanic friend who had a customer fill her oil to the top of the dipstick with disasterous results afterwards.

[Big Bruin]

I over do it just about every change. With a 4.5 quart capacity and 5 quart jugs, I don't even worry about being accurate. Somewhere close to a whole jug goes in each time... and one time the whole jug did.

I wouldn't worry about it.

[beagler]

Originally Posted by theirishscion

That's a good question. One to which I an only reply with opinions, not facts. Others may wish to weigh in on the topic as well.

The risks around overfilled oil all seem to come down to the spinning crank hitting the oil and frothing it up, assuming that the oil isn't so overfilled as to be cresting the crank bearing seals all the time, in which case it'll presumably start to leak out even when stationary. Frothed up oil doesn't pump well, leading to possible oil starvation in the head and elsewhere in the engine. I suspect this can also choke up the positive crankcase ventilation system, upping crankcase pressure and causing crank seals (and perhaps other gaskets) to leak or even blow out. The crank kicking the oil up against the bottom of the hot pistons might supposedly cause it to burn and carbonize as well, though whether this would be the case in the Pilot I don't know.

However, all of this presupposes that the oil level is high enough to catch the spinning crank. It's my sense that for a big-ish V6 engine, with associated big-ish sump, 1/2 a quart of extra oil is only going to raise the sump level a small fraction of an inch, and there's quite a bit of leeway engineered into the system to allow for driving on hilly train and sloshing during long high speed corners. I'd personally start to get a little concerned at a full quart over, though I bet it'd take quite a bit more than that to cause real damage. This is of course a good argument in favor of higher quality, anti-frothing engine oils, y'know, just in case. But then I'm a compulsive over-maintainer.

Considering you have already corrected the problem before any symptoms showed up, I'd say pretty categorically that you won't have done any damage. I'd actually be prepared to bet that you could have run the full 7500 miles with 1/2 a quart extra without doing any damage whatsoever.

Keep in mind also that the high school dropouts manning the air wrenches at the Qik-E-Lube-Stop-Wrench-Center couldn't give a rat's patootie about your exact oil level. If they manage to navigate the sump plug back in without cross-threading it and remember to screw on a new oil filter before you drive off, they're on target to make Employee of the Month(*). They overfill and underfill All The Damn Time, and you very very rarely hear about engine damage when they do, most manufacturers allow a lot of leeway (with some notable exceptions, VW/Audi is the first that springs to mind), usually the customer just comes back angry because their car's running funny and spewing engine oil all over the road from breather tubes, the shop drains off the excess, apologize and sends them on their way. No further harm done. Complete loss of engine oil is where you get the quick and catastrophic engine damage, usually the result of stripping out the sump plug (which quickly falls out after the customer leaves) or forgetting to put any oil at all in. Believe it or not, it's not that uncommon for them to drain the ATF and refill the engine oil, thereby adding 4.5qts extra engine oil and leaving the transmission empty. Now that's what I call overfilled!

(*) In reality, Employee of the Month (also commonly known as Continued Employment) is reserved for the urchin who up-sells the most expensive and unnecessary add-ons to poor trusting folks who don't know any better, then doesn't actually bother doing them. Just search Google Videos for 'jiffy lube scams' for details if you feel your blood pressure is dangerously low at the moment.

Thanks for the response. You are so accurate about the guys at the "quick lube" places. I had a recent experience with one, and it really made my blood pressure rise.

It sounds like my 1/2 quart mistake was not a big deal. I am thankful for that.

[N_Jay]

Take it out for a quick high RPM spin and check for foam. No foam, and you are good to go.

[beagler]

Originally Posted by N_Jay

Take it out for a quick high RPM spin and check for foam. No foam, and you are good to go.

This will sound ignorant, but how do you test for foam?

[theirishscion]

Good question. Foam on the dipstick perhaps? Never actually seen frothed engine oil.

[N_Jay]

On the dipstick should be fine.

[1YESfan]

I've seen a bit of oil froth on an 18,000 rpm racebike but never a car unless it's "detergent" oil. ;-)