Nissan Repair: Low Oil Level, engine seals, valve seals

Question
QUESTION: Hi. I have a 2002 Infiniti I35, bought used, now has 176K miles on it. I have been adding an unusual amount to top off the engine between oil changes. I am adding 1-2 quarts of oil - when I check the oil the dipstick is low. I do not notice any oil on the ground or blue smoke from the tailpipe. What can I do to correct this problem? Also, how do you keep the plastic headlights clear? Thanks for your time.

ANSWER: Sean,

The rings and valve seals are obviously letting some oil by.  Not enough to need a rebuild.  But, enough that it is annoying.  I would try a few things to see if you can control the oil use.  First, when it is down a quart try a product called Restore.  It uses copper sulfate to aid the rings in their sealing process.  Another thing you can do is to go to synthetic oil.  I know Nissan does not recommend synthetic oil.  But, I use Mobil1 5W30 in all of my Nissan vehicles.  Heck, I even run it in the lawn mower.  It works great.  On an old engine it works much better at controlling oil use.

The headlights can be cleaned with a headlight cleaner product from the local parts store.  Get a kit for like $24 bucks and use your drill with the buffing wheel (bonnet) provided.  Perform the cleaning in the shade.  Keep the buffer moving as not to burn the plastic.  Do a small area at a time and clean as you go.  The headlights will look great.  Then, keep them polished with car wax.

---------- FOLLOW-UP ----------

QUESTION: Thanks. While looking under the car, I noticed that just above the oil pan the area is black and very dirty, like oil is drawing dirt, noticed that a small drop of oil was on the drain plug but I think that it is coming from above the pan. Pan gasket was done about 3 months ago. Do you think that the engine seals or valve covers could be leaking. Looked at valve covers in light, they did not appear to be wet. Appreciate your expertise.

Answer
Sean,

I would clean the engine and then look for the source of the leak.  The valve covers are the usual suspect since they are plastic.  The drain plug has a copper washer that needs to be replaced each time the oil is changed.  Most places do not replace this.  rockauto.com is a good source for drain plug washers.