Coulpe of oil changing questions

[RambleOn]

In the owner's manual for my car, the oil capacity says "4 quarts less oil filter". Now does this mean 4 quarts plus another quart if you include the oil filter? I don't know why they don't just give the capacity oil filter included, who's going to run the engine with no filter anyway?

When I changed my oil yesterday, I put in 5 quarts of Halvoline Synthetc 5w-30. The engine is a 3.3 liter Buick engine in a 92 Century. The level seems about right, maybe a smidge below the full line on the dipstick, but it's looks safe enough.

My other question is, after I finished the oil change (put a new oil pan plug in too, the old one was getting stripped), I started the car with the oil cap off. I noticed something sounded different at idle, so I noticed the cap off and quickly screwed it back on with the engine running. What kind of harm can this do if any? The only thing I could think of was it might screw up the oil pressure. The engine only ran for about 20-30 seconds with it off. What do you guys think?

 

[d33pt]

it doesn't do any harm.. dont worry about it..sometimes i like to take off the cap and look at my valves go up and down...

 

[MrBond]

Four quarts less oil filter means like you found out, it takes four quarts for the oilpan, plus some extra for the filter. 5 quarts total seems about right.

Leaving the oilcap off isn't a huge deal, especially for a short time (I put in four quarts of oil, start the car and let it run for 30sec, then turn it off and add oil as needed, the whole time the cap is off). For longer periods (and actual driving) the oil can, and often will, come out of the oil fill cap. Then, you've got an engine running with no oil, which is VERY bad. Happened to my sister a few years back, she took it to some "!5 min oil change" place and they forgot to put the cap on. She heard her engine knocking, so she popped the hood and found an oil covered engine and a missing oil cap. But for 30sec-1min, you should be fine. You could probably go longer, as long as you didn't drive like that.

 

[RambleOn]

Thanks, yeah it just idled for about 20 maybe 30 seconds, so no harm done.

 

[Bleep]

The clickty click that you heard was because the oil pressure had not built up yet. It had to fill the filter before any oil pressure appeared. If the oil filter is vertical (they should all be vertical but are not) fill the filter first before putting it on, a little easier on the engine.
Bleep

 

[Thegonagle]

It's best to pour some oil into the new filter before you install it. It helps reduce the time the engine is running without oil pressure.

Since that tends to make a small mess, one other thing you can do is disable either the spark or the fuel pump, and crank the engine until the oil light turns off. Then reconnect the distributor or fuel pump and start the engine normally. (Caution: if you disable the spark, but not the fuel, the cranking can flood the engine, in which case you should floor the pedal and crank for about thirty seconds, then stop, let go of the gas, then attempt to start it normally. Yes, this works on fuel injected engines, too. I live in Minnesota, so I know about flooded engines.)

 

[Zenmervolt]

<< The clickty click that you heard was because the oil pressure had not built up yet. It had to fill the filter before any oil pressure appeared. If the oil filter is vertical (they should all be vertical but are not) fill the filter first before putting it on, a little easier on the engine.
Bleep >>

Alternately, if your car does not have a vertical oil filter (filter is horizontal on my Honda), you can disconnect the coil from the distributor and crank the engine for about 10 seconds. That should circulate some oil into the filter. Then check the oil level and add oil as needed. You may have to repeat the process twice.

ZV

EDIT: It would appear that great minds think alike, and also that I'm not quite as fast as Garfang.

 

[Thegonagle]

<< It would appear that great minds think alike. . . >>

I was thinking the same thing.

 

[Jerboy]

<< Four quarts less oil filter means like you found out, it takes four quarts for the oilpan, plus some extra for the filter. 5 quarts total seems about right.

Leaving the oilcap off isn't a huge deal, especially for a short time (I put in four quarts of oil, start the car and let it run for 30sec, then turn it off and add oil as needed, the whole time the cap is off). For longer periods (and actual driving) the oil can, and often will, come out of the oil fill cap. Then, you've got an engine running with no oil, which is VERY bad. Happened to my sister a few years back, she took it to some "!5 min oil change" place and they forgot to put the cap on. She heard her engine knocking, so she popped the hood and found an oil covered engine and a missing oil cap. But for 30sec-1min, you should be fine. You could probably go longer, as long as you didn't drive like that. >>



On some cars, the back pressure in valve cover is a must. My friend's Camry loses RPM and stalls when you take off oil cap while idling.

On the oil capacity, it's better to be slightly low than too high. You can be low by 1quart without a problem. When you're one quart low, the dip stick will read "fill". Overfilling can cause problems on the other hand. Fill 4qt, run the engine and top off as necessary based on dipstick reading.

 

[Cyberian]

<< On some cars, the back pressure in valve cover is a must. >>

Where does back pressure in the valve cover come from?

 

[SuperSix]

<<

<< On some cars, the back pressure in valve cover is a must. >>

Where does back pressure in the valve cover come from? >>


It's not "back pressure", it's vacuum, a function of the PCV (positive crankshaft ventilation) system, that scavenges oil fumes from the engine and burns them, helps the engine be more ecologically friendly.

As with any engine, a loss of vacuum will cause stumbling, poor mileage, etc. Vacuum is a vital component in engine function.

 

[RU482]

Also, in addition to adding some oil to the filter prior to installation, be sure to lubricate the filter gasket with oil too

 

[Jerboy]

<< Also, in addition to adding some oil to the filter prior to installation, be sure to lubricate the filter gasket with oil too >>



What about making sure to not forget old oil filter gasket stuck on the block and install a new filter on top of it

 

[helikon]

Ramble On, Yes the oil filter requires some oil to fill it but most oil filters don't hold anywhere near a quart,so by adding a quart for a much smaller filter leads to an overfilled condition.Regarding "back pressure in the valve cover" there shouldn't be any.If you remove the oil filler cap of an idling engine and it "puffs" out pressure and spits oil then most likely the piston rings are shot and combustion pressure is going past the rings,pressurizing the crankcase(oil pan) and then the pressure is coming up through the oil return ports in the heads and puffing out the oil fill port.Many cars require a certain amount of VACUUM in the valve cover(the engine really) to idle and run properly.Removing the oil filler cap causes a huge vacuum leak which can stall the engine if not make it idle poorly.On many cars just pulling the oil dipstick will create enough of a vacuum leak to affect idle.The amount of vacuum is critical to engine performance as well as scavenging crankcase vapors through the PCV valve . Hope this clarifies and doesn't confuse the issue. helikon

 

[RambleOn]

<<

<< Also, in addition to adding some oil to the filter prior to installation, be sure to lubricate the filter gasket with oil too >>



What about making sure to not forget old oil filter gasket stuck on the block and install a new filter on top of it >>



oooooooooooooo I had this happen once! I put the new filter on, started the car, and oil was pumping out of the filter like blood out of an artery. I thought the filter just had a hole, so I jumped in my truck and went down to AutoZone, got a new filter, then when I got home I realized it was just a stuck gasket.

I also lube the new gasket before screwing it on. Wait that doesn't sound good, but you know what I mean