I have been using Mobil 1 full synthetic 5w-30 the last couple oil changes and for some reason the oil gets really dark after 3000 miles. When it's first in there it's crystal clear but after just 3000 miles it's considerably darker. Is it supposed to do this or should I switch oils? I've never had problems with Mobil 1 before on other cars...

 

Darker color doesn't necessarily indicate a problem. Have the oil analyzed by a lab and you'll know if there is anything amiss.

 

Unless the engine has been abused (slugged up or something) having the oil turn dark soon generally indicates that the additive package is working well... have your oil analyzed to be sure.

 

Or, before your next oil change flush your car's motor with a motor flush
from your local Pep Boys.
They work well but be sure to follow the instructions.
It's not expensive and only take a few minutes to do, but cleans
the motor out VERY well.

Darkening oil doesn't mean it's not good though.

 

I agree with all the replies but this one. Motor flushes are VERY caustic. It has to be to "clean" the engine within the 15-20 min that you run it. It's way TOO caustic.

Since we are talking about the VQ35 and G35, I doubt this engine is in THAT bad of condition to resort to an extreme engine flush like you are suggesting. There are MUCH gentler ways of cleaing the engine out. AutoRX is one and is considered safe by oil user fanatics.

 

I second that...

 

third

 

Yeah, you are probably right for newer engines.
I've never used the flush on newer engines, but it works
like a charm on older engines.
Again, this would be something you'd only want to
do once.
Not sure how many miles are on the OP's engine, but
if it's got 60K+ it might still be something to think about.
I know several people who've done this to their cars
after they've racked up miles and their cars engine oils
looked amazingly clean after 3K miles of driving on an engine
with 100K+ miles.
My father's car with 180K miles on it, he did this twice.
His engine only looked better after 3K miles than mine
did on a car that had like 30K miles on it.

 

For those of you using Mobil 1, what kind of oil change intervals are you running? I'm at 4300 miles and I plan on doing one at 4500 and getting it tested by blackstone labs.

 

if u can't analylize,try rubbing oil between your fingers and if feels gritty then change is good or if it smells burnt change is also good.