Bought my g35 with 77k on the engine in 2008 and it has been drinking oil every single mile since then...I put 5 qts in and barely get 2 qts to come out after 5000 miles EVERYTIME I changed the oil in the last 7 years.

The engine runs ok with 197k on it right now but I think running low on oil is gonna catch up on me. Hoping I can get another 3-4 years out of the engine and original clutch before I sell the car.

I have calculated that the engine burns 1 qt every 1666.67 miles (3 qts burned divided by 5000 miles driven)

So what I have decided to do is put a fresh 5qts in and after every 1666 miles add 1 qt of oil. That means the car will never have less than 4 qts at any given time. A fresh qt will be put in so often that the oil should stay pretty clean.

Consider it an Intra-venous oil change...What do you guys think of this idea?

 

I use an oil pump to replace 2-3 quarts of oil around 2k miles before a full change at 4k miles. This is on my evo x though and like freshened oil for the turbo. My z goes through about a half quart every 3k miles I just top if off at 2k and change it at 4k with synthetic.

 

If your description is accurate and you've been allowing your G to go 5K miles and burning through three quarts before changing the oil/filter over the past seven years, the damage has already been done. The VQ relies on fresh, clean oil to lubricate critical wear items like the rings, bearing and timing gear. There's undoubtedly been wear on these and other reciprocating parts, I'd suggest saving some money for a full engine rebuild in the near future.

When you have an engine that burns oil, you should be checking the oil level frequently and adding oil to at least the minimum level (4 quarts) to prevent premature wear to the engine. I wouldn't wait 1,666 miles to add a quart of oil- depending on how the car is being driven and other changing conditions, it could accelerate oil usage well beyond a quart. Wear does not remain static- as the engine wears, it'll also use more oil over time. The only thing to do is nurse this VQ by checking the oil on a weekly, or even daily, basis.

 

Yes you can add oil if it is low, very common with any internal combustion engine.

Btw, try a PCV valve, it may help.

 

I can't imagine not checking oil on a weekly basis in an engine known for burning oil. I guess I just grew up in a different time and we always checked the oil every time we bought gas. I used to drive an Austin Healey Sprite that burned through a quart of oil in about 500 miles. And that was a brand new car. I carried a quart of oil in the trunk and added oil about every third gas fill up. It had an 8.5 gallon fuel tank so needed gas fairly often. It just seems logical to me that the dip stick should be checked often.

 

Really I want to know why the car is burning oil. It's NOT a 05-06 Revup, it's a 2004 g35 6mt and burns just as much oil as the Revups do. Seems like nobody knows the reason and just replaces the engine...if I did that maybe I would get another engine that does the same...what is the cause?

I am always afraid of adding too much oil, do you think that would hurt then engine any worst that what is done already?

The dip stick seems very hard to read

 

First off, to check the oil level accurately, do it first thing in the morning before startup. Most of the oil has settled into the sump. Clean the dipstick and check the oil level at that point usually results in a cleaner reading. As long as the oil level is somewhere on the dipstick, you can gauge how much to add. BTW- it's about one quart from the minimum level to the max line.

Overfilling a VQ is not good for the engine, either. Try this method and make it a habit to get a better idea of what your oil consumption is.

 

That helps thanks, I will take a look at the stick, but really it burns a lot...I guess the stick will help me better determine when exactly to add it

 

I hate trying to read the dipstick as well. I usually mark/remember how much oil is in my new bottles and then pour the old oil into them after I've done a change. I always assume some oil will be lost just because it sticks to the pan, is in the filter, or I spilled. That at least lets me see if I'm burning any significant amount.

Like mentioned above, your best bet is to check in the morning. Just make sure it's sitting on level ground of course.

 

Yea that's what I do, pour the old oil back in the empty jug so after every 5000 miles I have been burning 3 qts consistently

 

If I was burning oil I would doing a shorter change interval I think. Hell I don't even go that long as is. Oil is cheap, engines are not.

 

I'd step up my oil change frequency to 2500 miles and see how much oil you loose on the shorter change interval. I suspect you burn more oil in the second 2500 miles than the first as the more you lose the more wear the remaining oil sees and the more wear the oil sees the thinner and more broken down it becomes and the greater chance the paraffins start sticking to internals.

 

You guys are pretty helpful, thanks for the great advice

So what is it- is it the RINGS?

 

Any mechanical system can fail, regardless of design. If you've been running at 2qts for extended periods of time, consider yourself lucky that the motor has lasted this long.

 

Rings, cylinders... most likely rings.

 

I'm going through similar issues on my 06 rev-up. The strange thing is my 06 was one of the very last to be produced (November of 2006). Which leads me to believe the original owner didn't follow proper break-in procedures. Many revup owners report no oil consumption issues at all and from my understanding (based on the research I've done) the major oil consumption issues for 06s were found in the early release revups.

My engine runs solid with 76k miles, compression is good. But every 3k miles when I change the oil/filter I see about 2qts of oil lost. I've tried many different things to help alleviate this issue. I had a simple OCC installed for a while and I was catching quite a bit of oil in it. So the PCV system is highly suspect. Still trying different things here, but that's a topic for another day.

Since you have an HR, that's probably what I would check first since those engines are not known for consuming oil. I'm guessing you already checked underneath the car and didn't locate any signs of oil weeping/leaking. The next logical guess would be worn rings.

You can try a compression test and/or leak down test to get some more insight into the problem. If you can confirm the rings are shot, and the car is in overall great condition, I would say drop the coin on a rebuild.
-Icer

 

My rev up didn't burn a drop until I modded it now I only go through about a cm worth on my dip stick between changes I'm sure this will get worst in time. I'm at 39000 miles so still low miles for a 06. Mine was built in August 2006. Really you have got lucky burnin that much oil and it's still going just keep It topped up and drive on. Good luck

 

try mobile 0w40 euro (acea a3 rated)
it's a thin borderline 30/40 wt oil.
can be had at walmart for like 26ish.

and what kind of oil are you using now?

 

Yea I was thinking about doing the leakdown, how much does a ring job usually cost because overall my car is in pretty good shape.

I don't know why my 04 non revup burns as much oil as the revups, well after all it is a very similar engine

For the last few years I've been using 5w30 mobile oil $23 for 5 qts because it's cheap. But over the last couple changes I've been using 10w40 because I heard the higher the numbers the better it would be with oil comsumption

 

Changing rings usually means rebuilding the engine. To get to them, you've got to pull the heads (and may as well do a valve job while they're off) and disassemble the shortblock. While the crank is out, you may as well check and hone it for new rod and main bearings. If nothing else needs to be replaced (there always is), hone the cylinder walls, gap the rings and reassemble. Quoting pricing makes little sense, as machine shops around the country vary widely, but count on 2-3 thousnd.

Crap- that advice on oil consumption is outdated. There's a thread here on this site that you should consider reading: https://my350z.com/forum/engine-and-...-and-info.html

This landmark thread is long, but at least peruse the first page, as there's plenty of facts on which oils have gotten the best results with the VQ engine.