Newbie Oil question - HELP

[Tahoemofo]

I recently purchased a 2004 G35 Coupe and absolutlely love it. It currently has 23000 miles. It has been maintained properly (per the records) but when I checked the oil yesterday while getting gas - the oil looks really dark. This is probably a stupid question but is this normal? Is is becase of synthetic oil used or some other problem. I am not used to seeing this dark oil on the dipstick. I am naive and worried sick that there may be something that I overlooked when I purchased the car. Any thoughts????

[TJMaxx98]

Do you know the last time the oil was changed by the last owner? I would go ahead and get the oil changed ASAP!!!

[Tahoemofo]

It was due to be changed 4 days ago. Does in normally get so cruddy around the time change is required? I am getting it changed tomorrow and will also ask the dealer about it. Thanks.

Also - this site rocks. I got so much useful info from this site before I made my purchase. Thanks for your help.

[joe603]

Yup, if your getting close to the change time, the oil will be dark. Put some good synthetic in...I recommend royal purple, and a new filter. If you can, change it yourself to get a good look at what comes out. Its really not that hard and not messy if you take the aero cover off.

Once you change to synthetic, you should only need to change it every 7k or 6 months...but I usually do it at 5k or 4 months.

[TJMaxx98]

It was due to be changed 4 days ago. Does in normally get so cruddy around the time change is required? I am getting it changed tomorrow and will also ask the dealer about it. Thanks.

Also - this site rocks. I got so much useful info from this site before I made my purchase. Thanks for your help.

I just changed mine over the weekend...it had around 3000 miles...the oil was not too dark. It really just depends when the last oil change was done and the miles that have been driven. It will look pretty bad at 5000 miles plus if you are using conventional motor oil.

Joe603 gives some excellent advice....use some good synthetic. There is tons of info on the web backing up why it's a good idea. It might cost a few extra dollars, but it is much easier on your VQ35 engine....esp if you drive it hard!!!

[SVTCOBRA]

Yep, listen to Joe, he loves his cars, he uses ZAINO too!

I use Mobil 1 syn in all my cars and change it between 3.5k and 4k

First time I changed the oil in the G, I left the aero cover on and made a mess.

[g_ride]

hey this might be a dumb question but i was told before that ur not suppose to change to synthetic after you have used conventional motor oil its messes up your motor is there any truth to this i have a 03 coupe with 19,000 miles on it

i loved using synthetic in my last vehicle but i started it out on that so i was sketchy about switching it over on my G

[gjohnson66]

I do believe that you are listening to old wives' tales. Synthetic oil is infinitely better for your motor. Go ahead and change it and you will probably notice a difference right away.

[G_whizz]

Welcome to Nico!!

[joe603]

You should be fine to switch to synthetic; that was more of an issue with older engines...and even then, it was never proven to be true (to my knowledge).

A good synthetic will help keep the engine running at peak performance. Just use the proper weight to your climate.

[87ninefiveone]

Oil should be dark when you change it. Thats means its working correctly and emulsifying (i.e. collecting) the crud floating around in your engine. Its nothing to worry about.

Switching to synthetic oil does cause leaks, but not for the reason you'd think it does. Most synthetic leaks are caused by cleaning out the crap/sludge left over in the motor after using dino oil that was clogging what would otherwise be leaks. Synthetic oil does a better job of keeping the engine clean and ends up cleaning out leaks that weren't previously there (actually they were but they weren't actively leaking). This isn't something you should worry about with a new engine. Most of the time only older cars that have already had time to develop leaks with regular oil will have this problem.

Switching to Redline, Royal Purple, Mobil1, etc... is a good idea. Also, if your going to buy the good oil don't skimp on the filter (never use a Fram, EVER!). After the switch just continue to follow the recomended 7500 mile change interval and you should never have any oil related issues.

[roofrecon.com]

I heard from a dealer that you should wait to use synthetic on the G35 until roughly 20k because the parts have to set or something..this guy was dead serious...so I switched to mobil 1 and he said change it every 3500 miles...the car does feel like it does run smoother.

[G_whizz]

Would luv to see pics of that "custom dash"

[g_ride]

so wuts the deal with fram oil filter which one is recomended if your not suppose to use fram

[crispixoo7]

um yeah, more info on the oil stuff would be awesome...just found the site/bought an 07 G coupe w/ 150 miles....breaking it in nice and slow until 1200 (driver manual recommended)

[87ninefiveone]

For additional info on oil, filters, etc....

http://members.rennlist.com/oi...1.htm

or

http://www.bobistheoilguy.com

You need to stay away from Fram because they use cardboard endcaps in their filters. Needless to say oil soaked cardboard isn't exactly the world's most reliable material, so unless you want chucks of cardboard possibly floating around in your engine its best to buy a decent filter (i.e Mobil1, K&N, Wix, etc....).

[g_ride]

thanks for the advise is the sedan and coupes filters the same size

[G_whizz]

Good info!!

[Ang]

Hi Everyone,

New here. New '07 G35 Sedan bought in mid-Nov '06. Awesome wheels! Ready to go for first oil change (late, I know!). Shall I take the plunge & go to synthetic? I'm a frequent commuter to NYC.

[87ninefiveone]

How many miles are on the car?

I see no problem with switching to a synthetic. Just make sure which ever one you use conforms to Nissan/Infinit guidelines (i.e. the oil's API grade meets or exceeds guidlines). Go with the lowest viscosity oil recomended, and above all, keep your receipts to make sure you won't have any warranty issues.

[Ang]

oops - sorry - meant to mention 4,200 miles so far.My oil change place uses Mobil 1, which as I've read through various threads seems to be ok. They still said that I need to change the oil at 3K, but I thought that w/ synthetic, this would decrease the amt. of oil changes per year. I'll push it to every 5K. Whaddya think?

[87ninefiveone]

To keep a valid warranty all you have to do is abide by the Nissan/Infiniti 7,500 mile change interval. Since they've speced out regular oil for a 7,500 mile change you should have no problem going for 6 months or 7,500 miles on a name brand synthetic. Anything more often than that will just be piece of mind.

With the newer synthetics there's no reason to ever change before 7,500 miles as long as a good filter is used in conjunction with the oil.

[kmech_7]

look the reason you need to change your oil every 3000 miles is because of viscus breakdown. what this means is that after this amout of wear the oil itself is breaking down at the molecular level. The differance between regular oil and synthetic is the size, spacing, and smoothness of the make-up or mix in the oil. you need to break in an enge with regular oil for about the first 10,000 miles for all the parts of the engine that get oil soak up the oil into the thermal cracks. (yes for all of you peolpe out there whom are not machinests like me, metal is porus too, which means it will absorb liquid). First you need to understand that there is thermal cracks and piting in all metal. you will never see this, infact you need a microscope at 120x to see it. After about 10k your engine will have conformed itself to...well, itself. You can then use synthetic after that. I highly recommend you use it too. Now for the make-up of synthetic. Synthetic oil compaired to regular oil is almost 100 times smaller in partical size. now when you use this oil it creates a lot less friction in you engine. less friction = less heat and wear on the parts in your engine. you have now used the regular oil as a barier in your engine. the regular oil is still soaked into all parts of the engine sealing the synthetic from the thermal cracks, now the synthetic cannot get in the block deeper. But you ask me, well kmech_7 why wouldnt i use the synthetic in the first place since less friction seams to be better? Well some friction needs to be there in your engine all the time. without it you will blow the engine. the parts need to have heat applied to them to conform to eachother. that is why for the most part people in manual trans cars warm-up thier engine before they drive.

i hope i answered some questions. if not post more questions. if you think im wrong, im not, so screw you....lol.

[87ninefiveone]

I think your way off base with some of your commments. Most of what you just said is stuff that was true 20 years ago when synthetics were just coming on the market.

Its never necessary to use a conventional oil to break in an engine. The vast majority of high performance manufacturers (Porsche, BMW, Mercedes, Corvette, Viper, etc....) put synthetic in their engines to begin with and have no recomendations regarding a convention oil break in period of 10,000 miles.

The 3,000 mile oil change is a myth. Not a single manufacturer now recomends a 3,000 mile interval exclusive of an "extreme conditions" schedule. Addative packages in both conventional and synthetic motor oils have come a long ways in past couple decades and can now easily withstand the 7,500 mile intervals that are recomended without becoming badly oxidized.

Next, synthetic oil particle size is not 100 times smaller than a conventional oil. Synthetic flows and lubricates better due to a more uniform makeup which leads to less steric hinderance on a molecular level in turn allowing a more consistant viscosity over a larger temperature range. That said 10w-30 oil is 10w-30 oil regardless of the fact that its conventional or synthetic, and this means that at startup and operating temperature it will have the same viscosity, and viscosity is not consistant with lubricity, which is largely due to an addative package in the oil.

If you'll take some time do read through the link above you'll find plenty of info from chemists and car enthusiasts alike who have a lot more knowlege on this subject than anyone ever should. Its good reading.

[BigWill]

I can tell you from personal experience that there seems to be an issue with using synthetic in older motors. I had a '95 BMW 525i before getting my G. The Bimmer went to my son. I had kept the oil changed in it very regularly, (3,500 to 5,000 mile intervals.) My son, once he got the car, went right away and had the oil changed, wanting to start fresh.

He did so without consulting me about what I was using. He assumed that synthetic was better in all cases. The motor had about 120k on it, and ran like a swiss clock for me. As soon as he changed to syn, the car began a HORRENDOUS ticking. He told me about it, and I told him to go right away and have his mechanic change back to dino-oil. Unfortunately, it was too late. He still has the ticking, and his mechanic told him that a lifter is sticking, and that he will have to have the top end rebuilt to eliminate it. Now, it may be a coincidence, but I don't think so. How about y'all?

[joe603]

What did the owners manual suggest?

[C-Kwik]

I can tell you from personal experience that there seems to be an issue with using synthetic in older motors. I had a '95 BMW 525i before getting my G. The Bimmer went to my son. I had kept the oil changed in it very regularly, (3,500 to 5,000 mile intervals.) My son, once he got the car, went right away and had the oil changed, wanting to start fresh.

He did so without consulting me about what I was using. He assumed that synthetic was better in all cases. The motor had about 120k on it, and ran like a swiss clock for me. As soon as he changed to syn, the car began a HORRENDOUS ticking. He told me about it, and I told him to go right away and have his mechanic change back to dino-oil. Unfortunately, it was too late. He still has the ticking, and his mechanic told him that a lifter is sticking, and that he will have to have the top end rebuilt to eliminate it. Now, it may be a coincidence, but I don't think so. How about y'all?

I doubt a synthetic oil is a direct cause here. Perhaps it was a ticking time bomb so to speak and the synthetic helped it along, but it was likely to occur anyways. I've switched the last 4 cars I've owned to synthetic after it had been using conventional oil and never had any problems.

[ezflow]

I doubt a synthetic oil is a direct cause here. Perhaps it was a ticking time bomb so to speak and the synthetic helped it along, but it was likely to occur anyways. I've switched the last 4 cars I've owned to synthetic after it had been using conventional oil and never had any problems.

I agree. It is possible the oil used had a stronger detergent that loosened up some contamination, blocking a lubrication path. But it was likely to happen eventually anyway, if that's the case.I don't think you would find many bimmers around NOT using a synthetic.

[pae9132]

well I'm not a mechanic but I have done some research about oils. I used to use mobil 1 in my 2001 maxima and now I use royal purple in my 2003 g35 sedan which has mods. I agree that a leak will only appear with synthetic if the leak was already there and just clogged by conventional oil. I have also read that although synthetic can keep going for thousands of more miles then conventional it is still good to change it at about 5 to 6 thousand miles because it is still collecting all of the junkwhich is in the engine which will affect the performance of the oil. I am satisfied with royal purple and also use a K&N gold filter for highflow.