I recently purchased a 1998 Maxima, and ran into a bit of an interesting issue. For context, on the 4th gen dipstick you have stamped crosshatches with H and L to signify High and Low (L xxxxxxx H). You also have a few C shaped dimples or cutouts that fall below and above the crosshatches. I've attached a picture of what I'm talking about below.



When I bought the car, the oil was filled above the 'H' mark, all the way to the dimple above it. I read that as overfull and since it was near time for an oil change anyway, I had a local shop change it. When I picked it up, I checked the oil and it was filled up to the dimple again. I told the shop manager, who assured me they had put 4.2 quarts exactly into the engine, and if it was overfull, it wasn't enough to be concerned about. I checked that they did replace the filter, which only holds about 0.3 quarts anyway from my research.


I don't trust the shop, both because this didn't seem right and because they messed up on a few other odds and ends I asked them to do.


Do you read these dipsticks from the dimples? Or is it between the crosshatches like every other car I've owned? If it is overfull like I think, I'm currently running 1.5 - 2 quarts high by my estimation. I'd like to pin this down before I have a different shop take excess oil out, since that could be a bad choice if I am wrong, and my main seals aren't leaky enough for this to be a self-correcting issue.

 

When exactly are you checking the oil? It should only be checked after the car has been sitting and not running for at least an hour or two. I read oil by looking at the cross hatched area.

 

I give it plenty of time to settle back into the oil pan, still high at that point. I have checked on level surfaces too. If there isn't some glaring model/engine specific reason as to why the dipstick isn't read by crosshatch (maybe Nissan cut costs by making 1 dipstick for several different engines and just measuring it differently on each, that was my initial theory) I think it's safe to bet that it's just high. It's just odd that two people made the same mistake back-to-back, which is why I questioned it in the first place. I've heard leaky main seals and rough idle can be symptoms of egregiously overfilled oil, of which I currently experience both. I'm about to take it to a different shop to see if they can drain some, I'll see if it helps the idle.

 

My guess is, both parties dumped in 5 quarts to avoid the hassle of measuring. Do your own oil change next time, add 4.2 qts and see what the reading is.

 

Are you pulling the dipstick out, wiping it clean and then reinserting it and then pulling it out and reading it? This will give you an accurate reading. And of course on level ground and give a couple minutes for the oil to drain all the way to the pan.

 

You're probably right, I went by another shop in person and talked to a mechanic. He was familiar with Nissan's and said the dipsticks can be kind of a pain to get an accurate read on. His opinion was that I was half to a full quart over. At that level I'm not quite as worried about frothing. The shop who changed the oil claimed they looked up the capacity and put that exact amount in. I find that difficult to believe, I assume that any sort of blockage or buildup in the engine large enough to displace an entire quart would be immediately catastrophic, and I've never heard of anything like that.

I half feel bad for how hard I pushed the first shop about the whole thing, since it may not be a big deal. Still, I don't feel that an accurate oil change is too much to ask for.

 

Yep, just like my dad taught me.

 

FWIW, I perform my own oil changes. My readings are always dead on and within the cross hatched area.

If you're unable to do your own oil changes yourself, I suggest you try a 3rd shop the next time around and see if you get better results.

 

I will start by saying that the VQ30DE engine is by far the worst I've ever had to check oil on. My '96 Maxima has 320K and I cuss it every time I have to do an oil change. Why? Because Nissan put the dipstick through a hole that drains oil from the head. I like to run the engine a minute or so after a change (to fill oil filter and get new fluid moving), then shutdown. It's a fool's errand to check it after unless you have a lot of paper towels or at least 30 minutes has elapsed.

I don't recall the dimples being that far above the crosshatch area on mine. If it's not more than a 1/2" above the true "H" mark, I'd just go with it and then change the oil yourself next time.

 

Looks like about half to 5/8" over, right in the grey area of vaguely concerning but not alarming. Was this about where you ran yourself? I know the previous owner ran it like this for at least a few thousand miles, I still wonder if it was high oil pressure from this or just age that got my main seals. Anyone ever put an oil pressure guage on one of these? I'd be curious to see what it reads.

 

If you're certain the car is on level ground and hasn't been run in a few hours, that's higher than I'd be comfortable with. But here's the quirk with these dipsticks-- one side often shows higher than the other, because the dipstick slides down an oil drain passage. If both sides are equal and repeatable, you can believe it. If one side is showing higher than the other, I'm skeptical of the high side.

My car takes right 4.25-4.5qt w/ a new filter every time and it puts it solidly at the top of the crosshatch, but never above the H mark. It's just tricky getting a good dipstick measurement.