MNRUNNER

I am on my 3rd oil change since changing to synthetic and I have noticed my oil level will not stay at the middle mark. After changing my oil the level is right were it should be but after about 1,000 miles its down right on the lower line. It seem to level off there and not change. It doesnt take that much oil to bring it back up. I did not notice this before I changed to syn. I have checked all over the engine and do not see any wet spots where it might be leaking. I have 109,000 on my 94 Runner I noticed the oil that is in there now is a nice carmel color after 3,000 miles I have been changing it around 3,500. Any ideas what it could be or is it simply burning oil?

nrgetic99

Couple of questions.

Did you change grade significanttly when you moved to synthetics ?

Do you place any paper underneath at night to check for leaks ?

Some synthetics can have problems with already hardened seals...some synthetics are not as good at swelling the seals as others and if the seals are old and hard (likely at 100k), you will lose oil past the seals.

David

butnut

As David pointed out, the weight of synthetic oil could be the problem. I run 0-30. Not recommended for higher mileage motors...might just be too thin/light and therefore 'leak'. Maybe a heavier weight synth oil?
butnut

MNRUNNER

0w 30 Mobil One. Do you guys think I should switch back to reg Oil. Since changing to synthetic it does seem to have lowered my idel a little. I am getting the best milage I have ever got, not sure if its because of the oil, chevron fuel additive, new toyota air filter,Porter Cable Clay,Polish & Wax (less friction or maybe because the motor is finally broke in

nrgetic99

I believe Mobil do a full synthetic 5W-30. Do NOT buy the tri-blend as this is not a true syntetic

Try it at your next oil change and see if it goes any better.

Mobil 1 is waay to expensive to be getting past your seals.

David

Hermes

David, not to hi-jack this thread, but been meaning to ask you...

Based on your professional experience, will it be harmful to switch the rear diff to Mobil1 gear oil? Mobil1 gear oil is 75W-90 and the owners manual states 80W-90 for the rear.

I already have Mobil1 in the front and transfer case as they called for 75W-90. The dealer did the work and would not put 75W-90 in the rear.

Thanks

nrgetic99

Hermes,

Let me make some inquiries....we have probably the best geat technology out there and we supply a lot of wider cross grades such as 75W-90 and even 85W-140.

Let me run this one down.

David