Checking the oil - a weird question

[swank60]

Okay, this is bugging me. I'm not driving the truck that much these days (gas prices, no AC and it's TX - guess why I want to take the Avalon more often?) but here's my deal:

When I don't run the engine and check the oil, I show full on the dipstick. It's all drained nicely into the pan and none is really in the oil filter. When I run the engine (after shut down) and check it, it's lower on the dipstick - shows that it needs a little less than half a quart.

Here's where it gets weird. When it's full after an engine run, I seem to get smoke at start up after sitting over night, and it seems like there are a few other things too, but I can't think of them. Point is, it doesn't seem to be as "happy" with that extra half quart in there and tends to, I'm guessing, burn it off. Doesn't smoke or act weird at all when the oil is on the lower side...

Am I crazy? Should I be worried about 1/2 a quart? When is the "right" time to check the oil - after you've run it for a while, or after it's been sitting over night?

What a stupid and embarassing question.

 

[Landpimp]

I think smoke at start up meens your valve seals are leaking oil past them overnight.

you can check with a vacumme gauge, I recall if it bounces around it meens the vavle seals are prolly leaking

 

[Doc]

With a 7qt capacity, I wouldn't worry about .5 a qt.

I always check the engine oil level when it's warmed up. When the engine is cold it always reads lower that it should on my cars.

 

[Cruiserdrew]

The most important thing about checking the oil is having a routine. Mine is to check in my level driveway 10 minutes after hot shutdown. Always do it the same way and don't sweat the details. I do try to keep it near the full mark, and have added as little as 1/2 qt to keep it there. If you get smoke in the early morning, I agree your valve seals are worn. With quality motor oil costing .49-.69 per quart(Chevron on sale with rebate), it's hard to justify fixing unless you are making enough smoke to make the neighbors angry. Leaks are a different story-I really hate leaks and would work a bit to fix them. Try a higher viscosity and see if your consumption is less.

One other thing-Doc mentioned a 7 quart capacity. It's actually 8.5 with a new filter. That huge capacity is probably why these motors can last for such a long time.

 

[patride71]

weird to see this post because i just had the same issue with mine, but i have heard different schools of thought....have heard best to check when warm and heard complete opposite too, best to check when cold because that is a "true" reading on how much oil you have because it is all sitting in the pan.

i have always checked mine when it is cold. mine blows some white smoke when i start it each morning, but it only does it for about a minute tops. i guess seals are worn. it might burn some oil too as it needed about a quart today after changing the oil in it about a month ago. doesn't show any leaks though, maybe a dime size spot every other day.

 

[IDave]

I have to agree with Patride. Checking it cold allows all of the oil to settle. Checking it warm will give you much more variable results, and result in overfilling.

A friend, who is a retired certified GM consultant and mechanic, once told me how the folks at a dealership overfilled his oil when his wife brought it in. It smoked the whole way home, so he took it back to them, furious, and made them redo the job.

I don't think it causes damage (but maybe it does, I don't remember what he said), but I do think you are better off a quart low than a quart high.

 

[IDave]

Oh, and Patride,

White "smoke" is really water--steam. It probably is either normal, or the result of a slightly off choke (or some other emissions setting that I have no clue about), rather than a seal issue. I blow steam for a few minutes, especially on cold mornings.

















(yeah, I got the pun )

 

[patride71]

IDave
i did figure it could be something with the emissions too, rather than a worn seal, especially since it has been desmogged.

 

[swank60]

Well, the thing about the oil smoke is that it only does it when I'm "overfilled" on the first start. When the oil level is full and it's been sitting overnight, it doens't smoke. Also, the vac test is good and I don't get any movement in the reading - PO had the head redone and it seems to be holding up okay.

The danger in overfilling the oil is you have oil up too high in your oil pan, and the crank basically turns into an egg beater and froths the oil.

It just seemed like an anal question to ask, but I've been overthinking it for a month now and it was giving me a headache.

Thanks all!

 

[fsusteve]

It's better to be under some than over, but I wouldn't worry about 1/2 a qt though. Problems arise when yer talking a couple of qts.

 

[Stickboy]

don't know the specifics of the 2F but what I can say is that the fire trucks I drive at work always run a little bit down from Full. When they are "full" they leak and burn it off to a happy medium just below full. Detroit diesel motors so a little different, but I wouldn't worry about the .5 qt. and be happier with a non-leaky, non-oil burning motor....

my .02
-mike

 

[archie]

I heard that if you overfill it, the oil will slosh around rather than circulate within the engine. If you don't let the oil cool, then it could burn. Correct me if I am wrong.

 

[IDave]

How about this theory for Swank:

If the oil is overfilled the lower end of the cylinder is bathed in oil. Let it sit overnight and the oil creeps up the cylinder wall by hydrostatic (oilostatic?) pressure and gets past the rings above the piston, where it is there to be burned when you start out the next day.

Something like that must be happening: I don't think the valves would be involved because they are in the head, well above the oil.

 

[dogboy2]

maybe it's an old wife's tale, but it's my understanding that running with too much oil, increases the oil pressure which in turn (if too high) can blow out seals.....

hmmmmm......

-dogboy- '87 FJ60

 

[swank60]

Archie - It's not so much that it sloshes around and doesn't circulate - well, not exaclty. If it's overfilled (but it has to be a quart or more, I think) the crank beats it into a froth/foam and that won't circulate. I'm not sure what you mean about the hot oil/cool oil thing though.

Dogboy - I'm thinking that's a wives tale. The real worry of overfilling (and, again, it's got to be more than 1/2 a quart) is the frothing thing. Now, if you overfill an automatic transmission, it does increase pressure and blow out seals, IIRC. It's more of a closed/pressureized hydrolic system.

Dave - that makes more sense, kind of an oil creep thing. If there's too much oil in the system, and not all of it can make it back to the pan before it cools - or maybe it's more of a 'traffic jam', then it would creep into the cyl. and burn off - probably winds up in other weird places too...interesting that it's almost self-regulating, considering the system isn't really designed to burn oil.

 

[IDave]

Yeah, I suspect it isn't really good to be burning oil, even if everything else is normal. Might crud up your cylinders over time. I'd rather run it on the low side to avoid that happening. It isn't as if you don't have twice as much oil in there compared to other engines. We can afford to run them a hair low.

 

[swank60]

I would imagine that oil burn off would create a certain amount of tarnish and might contribute to dirtying up the oil. Also, over time, it'll clog up the cat (coats the catalyzing beads and makes them ineffective)

I think I'm just going to check the oil after it's been sitting overnight, and leave it at that. When the weather cools and I start driving it more, I'll get a better idea as to how much oil I'm loosing and to what.