Ok, so my 3.5 liter burns a lot of oil... approx. 1 quart per month. I really do enjoy high-rpms, and could really use the extra protection that synthetic oil provides. However, I heard that using synthetic oil in an already oil burning engine can make the problem wose. Is this true, or what have been people's experiences with using synthetic oil in an oil burner?

 

1qt/month , means something different for everyone, i.e., 1 quart / how many miles?

I don't currently have an oil burner and use synthetic w/no ill effects. My VQ30 is 13 years old w/ 240k and doesn't burn a drop of synthetic either so, that's my 0.02$

 

switch to castrol gtx or another good dino oil...try switching up to heavier weights if your current temps permit. I recommend 10w-30 even in the winter ONLY as long as your temps do not drop below 0*. You dont want to go too heavy of a weight at the same time b/c oil will have a harder time flowing throughout the engine.

Few people here made the switch FROM syn. TO dino and noticed less oil consumption

 

10-30 is 10-30, whether syn or dino, they're the same viscosity.

 

But 10-30 in synthetic is, like, a metric measurement vs std for dino...

right?

 

I know

 

cP vs Pa-s vs cS

 

...I concede defeat.

 

If you can afford the extra $3 a month for the synthetic, keep using it. You also might want to consider trying one of the high mileage oil blends and see if that helps.

 

I'm on castrol 5w30 currently.. but, i really wanna go synthetic, just to have that extra peace of mind, you know? i'm thinking synthetic 10w30 might be a good choice

you're right, and i was gonna put a mileage amount in my original post cause i thought about that, but i'm unsure.. i'll start keeping track if i can remember

yeah, castrol gtx high mileage was gonna be my other choice if i didn't do synthetic.. but i'm thinking synthetic 10w30.. by the time i change my oil next, the cold weather should be almost gone.. i think i'm gonna try that amsol signature series oil with like SUPERIOR burnoff protection -on a side note.. Mr. Detailing Guru, I've come to seek your wisdom. I made a post in the detailing section about tire shine, and hopefully you could help me out with your advice. Thank you in advance-

anybody else have experience with synthetic in their oil burner to compare to dino oil?

 

Why would you switch from 5-30 to 10-30?

 

I don't see why you'd want to switch to synthetic if you're burning oil at a decent rate, seems like just throwing extra money away to me.

 

yea keep adding oil in from time to time...then you'll never have to get your oil changed again

actually no, dont do that, I was joking

 

Your engine may burn synthetic at a higher rate than conventional oil, because its a better lubricant overall. Its not correct to say that it is making the problem worse though. If you ran synthetic for 2 months then switched back your oil consumption would return to the same amount as now.

Either way, synthetic is a better lubricant, and you should consider it if you can afford it. It may pass through your engine faster, but its still a better lubricant. Alternatively, one of the high mileage blends could be a good solution, too.

 

i was considering that because since 10w30 is a higher viscosity than 5w30, it wouldn't pass through the rings as easily, and would keep more oil in the engine... no?

 

i don't understand why it would burn at a higher rate.. in the demonstrations i've seen of synthetic oil, the oil kind of sticks to the engine parts, and is not so quick to run over the engine parts as dino oil is, and provides better lubrication because more of it stays on the engine parts for longer... kind of like the less exaggerated version of honey vs. water... with honey being synthetic, and water being dino.. maybe i'm mistaken...

 

 

Move along, nothing to see here. NmexMax and I have had our fun.

 

Heavier oil won't burn off as quickly so 10w-30 should burn a bit more slowly than 5w-30.

You think you have oil burning issues? I had a 1974 Z/28 that burned a quart of 60w oil every 40-60 miles.

I had bought the car with personalized plates already on the car...L88-Z28 and it turned out the 2nd owner put an L88 427 in the car and bracket/street raced it while the original engine, an L82 350, sat in his garage for a couple years. He ends up getting another car (Vega, I think, I got this info second hand) for the 427, put the 350 back in and the car ended up on a used car lot where I bought it. Pulled great (4 speed, headers, intake Holley 3310, 3.73 posi) but I could fog mosquitos when I punched it.

I ended up selling it to a friend of my now-ex wife, he never check the oil and blew the engine up, put the cam through the back of the engine and holed the block, then left it on the side of the road and told me I could have it back. Ended up parting it out since my ex was writing hot checks all over town and I couldn't afford to rebuild the engine.

 

Why mask/patch the problem by switching weights? Also, 10-30 will 'burn' as easily as 5-30 when heated.

 

5w30 and 10 w30 have the same viscosity when at normal operating temperature. That's what 30 stands for. The 5 or 10 (first letter) is a flow coeficient tested in a lab at low temperature (minus something forget the nr.) So you want the first number to be a 5 so you get proper lubrication on your galleys piston skirts camshafts and chain area etc when cold. You do not want your oil to be thicker when cold. Now if you burn a hudge amount of oil and wanna go beyound of what the manufacturer has tested as adequate lubrication for your engine components when hot and it's TOLERANCES you can use 5w40 weight oil. However i would recommend against that as it might not flow as good to lube your critical engine components resulting in even more damage.
Oil burning is a normal process of combustion and certain manufacturers consider anything less than 1L/1000 kms perfectly normal for their high compression and high revving motors. That includes the German manufacturers

 

you seem to know alot about oil.. what difference do you think using synthetic would make in the oil burning rate of my engine?

 

you would give it a try. It cannot be much more than dino if it even does matter.
I run synthetic too in a 3.5 and burn a qt every 2K and the more you high rev the more you burn. I could have gotten a free engine under warranty as a Nissan tech for free but opted not to as it is normal for these cars to burn oil. Many times we do swaps and they still burn.
Have you checked if your rear rockercover was leaking internally inside the spark plug tube? ALso change your PCV as a long shot.

 

I suggest you use Mobil1 High Mileage 10w-30. It might not help with the fact that you're burning oil, but it will not hurt the car. I have a rotary engine car, and the inside of the engine looks great - and rotaries actually inject some oil into the combustion chamber.

Dave

 

i have not checked the rear rockercover for leaking into the spark plug holes, but i figured that could be a possible problem.. is a rockercover the same thing as the valve cover? cause i heard those can leak... and how do we replace those? i remember looking for a writeup on howto replace the valve cover, but couldnt find one

 

Yes, 'rocker cover' is an older term for the valve cover.

Just unbolt the old one, put the new one in place and bolt it back up...

Requires removal of the UIM, but that takes maybe 10 minutes. Follow the first part of the guide here - http://www.vqpower.com/v2/readarticle.php?article_id=89

Disregard the EGR as 02-03 don't have external EGR systems. You also don't need to remove the TB.

After that, remove the coils and anything else obstructing the VC, then R&R.

 

Yeah I don't understand that either? After working at an oil change place for like 5 years I noticed that cars that recommended 5-30 year round and used 10-30 actually burned more oil. Like stated above the first number is the low temp viscosity and you need the 5-30 to properly lubricate when your engine is cold. Its funny how all the old schoolers think..." you burn oil, just put in a heavier weight!" Sure for an outdated, obsolete pile of single cam american v8 that only lasts for like 50-100 k. But truth is everthing on ours cars was designed to run with a certain oil for a reason. Technology has come a long way and a heavier oil than what is recommended, cold or hot will cause more problems than it will do good for our cars and any newer car. Don't change the viscosity, change the quality of what you're putting in if you want longevity out of you engine!!

 

I would check rocker cover. My mom's 3.5 burns and I have tried switching weights before no luck. I became more religious about changing the pcv and checking it. As, a result it burns less. Just my thoughts.

 

so it involves removal of the intake manifold.. hmm.. i'll probably do this when i get my IM spacers then.. what does the valve cover look like and where is it?

 

It's the black cover bolted on to the head.

 

According to Nissan both 5W-30 and 10W-30 are OK to use in the VQ35, depending on the climate where you live. Check the user manual.

 

VQ Oil Analysis and Info

 

thanx.. that had some pretty good general info in there.. but i didn't see anything about the notorious oil burning problem in VQ35's and which oil is best considering that.. did i miss something?

 

yes, it's in there. IIRC cliffs are: the 0w40 european blends that are hard to come across are preferred by the oil burners, err, aka rev-up owners. But someone might want to double check me on that.

 

I'd burn 1 qt per 1200mi,
changed oil with castrol 5w30 conventional, and a bottle of mucas synthetic stabilizer, and wouldn't you 2000-2500mi later the dipstick hasn't lost a drop.

Also no foaming or lights, contrary to bob the oil guy a.k.a(schaeffers+autorx spokesmodel) research.
Remember to use the synthetic stuff. I could be a fluke case but it's worth a try considering all this oil burning hysteria.

 

cough.... year old thread....cough

 

oh yeah, i remember starting this thread a year ago.. lol.. by the way, i burn WAY more oil than i used to.. probably more like a quart every 2 weeks

 

wow... that's starting to get serious...

 

Ouch.

Mine burns it at the same rate it did when I got it 30,000 miles ago. A quart every 1700-2000 miles depending on how I drive.

 

yeah... i mean, i do drive fairly aggressively as far as shifting at high rpms.. usually between 3-4k.. and alot of spirited driving... considering that, is my rate of oil consumption still considered abnormal?