Hey guys,

I recently bought an 04 350z with 89,000km (+/-55,600miles). I've read up about the dreaded oil consumption problems before I bought the car but off course there's no way of knowing until you actually own and drive the car yourself.

Anyways. When i got the car I couldn't get an oil reading on the dipstick, which I thought was strange.
I changed the oil and filter with fresh oil. Used Castrol Edge 10w60 as we have a fairly warm climate, and I do a lot of highway driving.

I overfilled the oil a bit. I'd say about +/-4.9L total and the level was sitting in the middle of the "H" mark on the disptick initially. I then proceeded to check the oil daily in the morning. It's a bit hard to get an acurate reading unless I check it in the morning after the car has stood overnight.

Now, the oil level has gradually decreased over the past two weeks form the middle of that "H" mark to about the top of the mark which indicates the Full level for the oil. (the correct full oil level). So I'd say it dropped by about 1mm to 1.5mm on the dipstick after about 1000miles. This with a mixture of highway and some hard/spirited driving. Is this normal or do I have the dreaded oil cunsumption disease??

I'm a bit worried as Im using a relatively thick oil and I didn't expect any movement in the oil. It could also be i'm loosing a bit of oil by checking the oil level too often, and constantly wiping a few ml of oil from the dipstick daily??

Think I'm going to drive the car for a week without checking the oil, then check it. How much does say a quart represent on the dipstick?

 

Most dipsticks are marked so the H-to-L difference is very close to one quart.

I doubt a drop of 1-1.5mm in 1000 miles is cause for concern, especially if the oil was a little over to start with and you're driving aggressively.

 

04's didn't really have oil consumption problems.

That small amount of apparent consumption is nothing to worry about. It could be the result of temperature difference, car sitting on uneven surface, etc. You shouldn't worry unless you're losing a quart in a 1000 miles (i.e. H to L on the dipstick).

 

Thanks for the feedback so far. Please keep it coming. You guys are giving me hope

I'd like to change to 5w40 synthetic as winter is aproaching but want to make sure I don't have consumption issues first.

Also, I think I will change the PCV valve just in case.

 

inbeforementioningstreetracinglock

 

+1

Also, most cars when you overfill them will burn off the extra oil over time. The amount of oil you're wiping off is almost negligible. Unless it drops below the 3/4 marking in the next week I wouldn't really worry.

 

fixed

Cool will keep an eye on it.

To the guys who have OC issues, does it also occur with regular everyday driving or is it only when you push the car a bit?

 

"Oil burner" is a bit of a misnomer. Whether the Z is "burning" oil in the combustion chamber or consuming oil by other means matters not. Its still a problem.

You can go to the expense of a compression check and repairs. Or you can simply add a quart when needed. Consider 1 Quart/month will cost about $48/year. Its not a fix but will keep the Z running.

BTW I drove a 2004 73,000 miles. Never added an ounce of oil.

 

You're displaying confusing behavior. Burning a quart of oil between oil changes isn't entirely abnormal for a VQ.

<quote>Used Castrol Edge 10w60 as we have a fairly warm climate</quote>

1) Why would you put Castrol in your car? It has high ash content and their synthetics aren't synthetic. Go get a good synthetic in the 5w30-10w30 range as per the Nissan recommendations.

2) You want the oil with the smallest viscosity range for your purposes. 5w30 and 10w30 are the recommended for the VQ. I think you're stupid to put in 10w60. Why did you want such a wide range? It means the oil has more stabilizers and additives, and is thus less effective.

 

Wow you have a whole 6 posts and you're running around calling other newbies to the VQ stupid?

I used the 10w60 cause I already had it, and I'm basically using it just to flush out whatever crappy mineral oil nissan used when the previous owner used to take it to them for services. I'm changing the oil out (probably in this week) for a proper synthetic - much like I stated in my post.

30 is probably too thin for our hot climate. The thinnest I'll go is 5w40. Else perhaps some Motul 300V. Right now it's turning winter so I could maybe get away with a 5w30 weight for the next 3 months, but in summer it would not be a good idea.
10w40 seems best suited for our conditions I'd say.

The aim of my thread is to figure out if the slight loss of oil is normal or if it is the common OC issue.

 

No, just one particular noob. I didn't say you were stupid, I said you were stupid in the act of putting 10w60 in your car. For a cold climate, I can see cold starts being a problem, but your justification is fairly weak.

Engines are designed for particular weight oils - altering your viscosity based on your perception of the exterior temperature is somewhat silly, given that the temperature of your engine far exceeds the ambient temperature while operating and is regulated by a thermostat. That means that cold-start temperatures are your real concern, and excess heat outside isn't going to thin the oil anything like the heat from the engine block itself while at normal operating temperature (200-250f typically). If you live in some area of the world where your car is running above that temperature on a regular basis, you need a better oil cooler and radiator because you are overheating the engine.

Do you live somewhere that your engine temperature is exceeding 200-250f? Does South Africa have ambient temps over that?

 

Hi Doc, I also have a 04 Z. When new, it did use a tiny bit of oil when I drove it aggressively. However, after a few thousand miles it settled down and has never consumed a drop since. (I might add that my aggressive driving has also settled down.)

Since the distance from the full mark to the low mark on the dipstick is about 30 millimeters and you’re only experiencing a drop of 1 to 1.5 mm per 1000 miles this will not constitute a significant amount between regular oil changes. In fact, you have a pretty good eye to be able to discern a one-millimeter variation on a dipstick.

 

200-250???????


uh...link to where you resource your numbers or GTFO

 

so castol synthetic 5w-30 isnt a good synthetic oil?? because i just put that in about a tad over a thousand miles ago and i get faint oil smells. Also, check to make sure no oil spilled and stuff. hmm i guess ill find out with my next oil change if it was the oil.

Any bad things about amsoil 5w-40 for san antonio, texas heat?

 

Doc,

I had an 05 Z that had the same engine as your 04.. as well as my 07 with the HR engine. Don't go heavier than 10w-40. Just don't do it. In fact, 10w-30 is actually more than enough, even in a hot climate. I'm in Austin, TX, where it will be 95-105 degrees for several weeks in a row. Nary an issue using even using 5w-30. Don't worry about the ambient. The car is fine with the recommended oil viscosity ratings, even in high-heat.

 

I'll be switching back to some thinner oil tonight. Probably Shell Helix Ultra full synthetic 5w40. My other options are Liqui Molly. Which would you say is better?

I really just needed to flush out whatever trace of the crap the dealers use out of the motor. So instead of buying some cheap oil I thought I'd put the castrol to some use.

ps: What could the heavy weight oil do to the motor?

 

Just checked my owners manual and for my temps it recommends 20w20 up to 20w50.

The nissan dealers around here use 20w50.

So I don't think the two weeks I had 60 in there could have killed anything.

nontheless, I'll be going to a 40 soon.

 

If your manual says you can use it, then don't even worry about it. Heavier oil is harder for the oil pump to move, therefore it makes the pump more prone to failure. It's also harder for thicker oil to properly traverse some of the smaller oil channels in the engine. Therefore, you may sometimes actually hurt your lubrication by using thicker oil. Once again though- if the manual says it's ok, then you should be covered if something goes wrong. That is, if the vehicle still has any sort of warranty left on it.

 

Hey Doc,

Congrats on the Z. I have a 2005 and originally tried the Amsoil 5w-30 Full Synthetic but found that the 5w-40 Full Synthetic European Formula didn't burn off near as much as the 5w-30. I am on the Gulf Coast of Texas and the temps average upper 90's - low 100's through the summer months.


Just use the 5w-40 and be done with it.

 

You are surprised at 200f for an engine?? I'm used to slightly different models of engines, but the numbers are similar for VQ35s, apparently - about 175-195f. These values don't matter - they are far above what you even find in death valley.

Here is an example from another forum for t-stat temps:
350Z 2008 - Opens 180F (177F-182F) - Fully Open .0.354"/203F - Fully Closed 171F

So now your turn - what temp did you THINK the engine would run at?
http://www.clubfrontier.org/forums/f...mostats-34393/