Hey guys, I've changed my oil like 3 times and I've done my dads on his 99se. Well I always pour almost 4 bottles in but I think thats the wrong way since well theres oil left from previous times. And well I'm either a moron or I dunno but the darn dip stick is always like too high up and it's way high on both cars so i dont know how much is in there? thanks sorry for the weirdo-moron question. btw getting my 02 lights monday im excited!

 

The proper amount is 4.25 per the owner's manual. The dipstick is hard to read after changing the oil but if you wipe it off then put the stick back in, then pull it out and feel it, you should at least feel where the level is.

 

When checking after operating for a while, pull the dipstick out and keep it out for a minute or two, put it back in and pull out immediately. Measure the level as being the lowest point on the dipstick completely free of oil, ignoring any smears of oil that come from the oil on the tube wall.

Oil gets into the dipstick tube, waiting a while lets it drain back in to the engine and keeping the dipstick out lets it drain quicker.

Checking first thing in the morning, before starting, it is also easier to read.

BuddyWh

 

I think BuddyWH has the correct answer. Check it in the morrning after it has not run for several hours, because if u check it after u changed oil or driven the car there is oil all over the inside of the engine. You have to wait till all the oil has drained down to the oil pan. When I change my oil I put in 4 quarts and prime the oil filter, then run it for the day, then the next morning I check the oil level and add what is needed. Hope that helped

 

There has been much discussion on various boards about the proper fill of oil. On the '98 VQ30DE the manual listed the fil to be 4 and 5/8 quarts with filter. I always put in five just becasue.
Before you (whoever you may be, there is always one) try to argue about that extra 3/8 of a quart being over fill, just stop and think about how much 3/8 of a quart is. Not much at all. Not enough to push the oil level high enough to get whipped up by the crank and lsoe power. And besides, when your engine is running a large portion of that oil is occupying space in the feed viens and gallies.

 

This is correct. I've tried both methods and they do work. Waiting until morning gives the cleanest reading. Using the dipstick method works but there will still be oil splach all over the stick.

When I change my oil, I just put in 4.5 quarts and then I check the oil level in the morning.

 

so if i put in 4 quarts i shoudl probably be safe, right? taking into consideration left oil inside there from past changes.

 

All you need to put in is 3 3/4 to 4 quarts. Anything else and you are overfilling the crankcase, which could lead to foaming of the oil. My first oil change I put what the manual says in (4.25) and when I took it in for service, the mechanic told me I had overfilled it. He told me that there will always be some oil in the engine that you cannot get out.

 

You're the one huh?

The Nissan engineers aren't stupid. Id bet they accounted for that little bit that can't be removed. Have you ever looked at the rest of the manual that shows extra oil when changing the filter???

 

I think you're right in that this little extra oil probably won't matter... but I you need to consider the issue isn't losing power if the crank contacts the oil.

The issue is the oil will be literally whipped into a foam by the crank, you may not even notice any loss in power as foam doesn't interfere much. But foam also doesn't pump very well if it gets to the oil pickup, leading to oil starvation and early failure. In the worst case the oil idiot light will go off with engine seizure following pretty quickly (that idiot light should be changed to read "Engine Seized".) Most likely you'll never know it's happening as the foam level gets to the pickup only occasionaly during a hard corner or stop.

I am sure Nissan engineers set the oil level correct for the engine, and with some margin for overfilling by the clutzes at lube-n-go which you may exploit. But be careful!

IMO, the safer way to increase capacity is with an oil cooler and/or extra filter(s). Many other engines can be fitted with high capacity oil sumps... basically an oil pan with a big bulge to the side(s)... I wonder if the Maxima could be so fitted.

BuddyWh

 

I had already stated that much of that oil isn't even occupying space in the sump, therefore it can't be whipped up by the crank.

 

Of course you did.. my comment is intended mainly for anyone else reading who might be inclined to follow your example. It's good to know they may not feel a loss in power at all until it's too late if they should overdo it.

Do you know a Max's engine has an oil pan baffle? high speed engines use baffles to keep the crank from whipping the oil not because it touches the oil but because the air (if you can call it that inside the engine) vortex created by the spinning crank is so great that alone draws oil up into the crank, where it is whipped. Filling the oil to the point it is over the baffle defeats that purpose even though the level is still not close to the crank.

And as I stated Nissan's engineer's doubtless set the level knowing the clutzes at a lube-n-go overfill... and that is what you're taking advantage of. But then they also set the level considering the effect of oil being up in the engine oil galleries, pump, and pooling in the cylinder head area.

For me rather than getting into a guessing game (is it over the baffle??? ) it's much safer to not overfill... and to not underfill. The marks are there for a reason and keeping my warranty in effect is one.

BuddyWh

 

Ive read the manual yes. 5 quarts is overfilling. You want the oil to be in the middle of the dipstick. When I took my car in for service the Service Manager said that I had put too much oil in. That change I put roughly 4 1/2 quarts. Like I said before she said that the engine retains a small quantity of oil in it, thus you should only use somewhere between 3.75-4.25 quarts.

 

Yes, all VQ engines have baffles.



It appears the only way I'll be able to prove if I am right or wrong is to somehow place a camera inside the sump while the engine is in motion.

 

Yup, that's kind of my take on it so I figure that's why they gave us marks on the dipstick.

A borescope would probably help... know any mechanics with one they'd loan you?

BuddyWh

 

No, you're supposed to check your oil with the engine hot. Been that way as far back as I can remember. From the manual (I'm gonna postwhore myself up a level just by continually quoting the manual. Paranthetical notes are mine... )

Now, I know that owners manuals were written for idiots, but it does have the recomended procedures from Nissan's engineers.

'Frinstance, how many of you know you're supposed to check your ATF fluid with the engine running?

 

the trick is this:

Remove the dipstick... and wait.. and wait. about 30-40 seconds. The oil that is messing up your hot reading will run back down the tube. NOW, take a reading. viola! its magic.

 

You can make the dipstick much easier to read by scuffing the chrome plating with Scotchbrite or emery cloth, function being way more important than pretty in this case. Just make sure that you wipe off the dust before putting it back in the engine.

Norm

 

While I agree reading hot gives a more accurate level, reading cold let's you read the dipstick easier so you're less likely to err. It's a compromise, but it works out well since the delta isn't great from cold and it will still fall between the "add" and "full" marks if the level is correct. I'd much rather operate just above the "add" mark that just above the "full" mark.

Engine oil level doesn't vary nearly as much as the auto tranny level does from cold to hot... don't know exaclty why, could be because the volume which is much less, could be the co-efficient of expansion is much less. Most likely a combination of the two.

Good point about checking auto tranny's: reading methods vary from car to car so you should always check the manual for your car's correct method: some you check with engine on, some with engine off, some with engine on and in park, some with engine on and in neutral. Some you consider the exact temperature of the fluid so you need a temp guage.

I remember a car my Dad had it was checked with engine on and in "D"rive! Sounds dangerous to me in today's law suit happy country.

BuddyWh