1998 QX4 Oil Leaks and Engine Oil Question

[eduJ]

I bought my QX4 used with only around 80,000km on it. The previous owner rarely drove it. Given that this is my first used car, I decided to try doing oil changes myself. Everything went really smoothly. I drained the oil out, and put in around 4 quarts. I checked this forum's general information page and it says that my car calls for 3.91qts. I may have put in slightly more than this by accident..maybe 4.1 or 4.2 quarts. The car started fine and I didn't check the engine oil level right away as I assumed that I was within an acceptable level. I went on a short road trip and when I got to the gas station to fill-up I checked my engine oil and it was over the "H" mark. As in, there were traces of oil above the letter "H". It seems weird to me that the dipstick would register so high given that I was over a bit. Is there any reasons for this? I drained the oil pretty good..waited for at least 10-15mins before putting the drain plug back on.

I didn't get a chance to drain oil out until a few days later. I drained like almost 2 quarts out. I checked my engine oil and this time it was lower than I wanted, but between the L and H mark. I put in like 700ml of oil back in, but now when I check my engine oil it is reading high. As in there is oil on the "H" mark, but not above it. I find the dipstick to be really hard to read on this car. I assume that I am still high because there is oil in the H indentation, but the level is suppose to be "between the H and the L. Should I bother draining some more out? I've done this draining thing a few times and it seems like I can never get it to be perfectly under the "H" mark.

As well, I've noticed some leaks recently. Two of them in fact. A slow rear main seal leak and probably front cam seal leak. Both don't really leave drops of oil on my driveway, maybe one drop when I start the car in the morning, but I'm assuming I'm dripping slightly as I am driving. Is it possible that I blew out all the seals by having too much oil in the crankcase? This car hasn't done any timing belt service yet, so I can change out all the front seals when I do the timing belt?

[Towncivilian]

Overfill by up to half a quart is nothing to worry about. You should check the level after the car has been sitting overnight, on flat ground. I believe you should be able to change out the front seals when you do the timing belt, correct. I would not worry about the rear main seal leak if it is as slow as you say; a high-mileage oil like Valvoline MaxLife 5W-30 may help slow or even stop it.

[eduJ]

Thank you for your response. Would any here happen to know how many quarts is from the L mark to H mark?

[Towncivilian]

Typically one quart.

[eduJ]

I find it interesting that the QX4 only takes 3.9 Qts. I have had cars with much smaller engines that takes more than 3.9 Qts. I noticed that the full engine capacity is somewhere around 7 qts. Does this mean that when we do a drain and fill, we are only replacing about half of the oil?

[Towncivilian]

There is a lot of oil that stays in the various oil galleys, etc when you drain the oil. 3.9 quarts is actually more or less typical capacity for a VG33E; Xterras have a similar capacity. I'd just dump in 4 quarts and call it good.