Hey guys, this is the first time im inquiring here for some professional help so in advance thank you for your free service.
My car is a Nissan Sentra SER Spec-V. So, it burns oil. A lot! I got my oil changed on sunday and today (4 days later) im 1 1/2 qt down. I do drive a lot so in this period of time I have driven 600 miles. But I know that this is a major problem. Heres what I have tested and done so far.
Compression test, 150 across all 4 cylinders. All spark plugs are good not fowled. I do not burn oil on idle only when accelerating. I am not leaking at all underneath however I noticed that on my valve cover I do have oil showing up next to the two left cylinders, also it seems to have gotten on the underside of my hood just above those cylinders as well. My mechanic says he thinks its the valve guide seals, and I should send the head to a machine shop and then get all new gaskets. But other people have told me they think its the rings due to how it is not burning on idle. What do you guys think?E
Start by replacing the PCV valve and be sure the hose isn't sucking closed. With oil residue showing up on the hood, that suggests the oil is blowing out as a vapor and condensing. That's caused by excessive crankcase pressure. If it was sneaking past the piston rings or valve guide seals you would see blue smoke from the tail pipe.
You can also add a small bottle of dark purple dye to the oil, then check a day or two later with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. Auto parts stores will have the dye for engine oil, and many of them have tools they will rent or borrow. The dye will show up inside the tail pipe if the oil is being burned in the engine.