Mrz1985

My YEAR of Oil burning problem. I have an 2003 350z. If I drive on the interstate at 2500-3000 rpm I lose about 2.5 Quarts of oil in a short 150 miles. The car smokes like crazy. The driver side plugs are oil fouled in 10k miles. When I removed the upper plenum, there was enough oil to spoon out. And the driver side valve cover has oil on top of the cover around the coils, but there is no oil in the tubes. I have 179 PSI compression on cylinder number 2, and 185 on all others. I pull a steady 21 inches Hg with no movement of the needle. My power is mostly there as long as the plugs aren’t fouled, and my fuel economy is in the high 20’s on the interstate. I know that a compression test is only an indicator of the compression rings. I don’t believe it’s the valve stem seals be of my good vacuum reading. I haven't had a chance to run a leak down test yet. I have had the car for 3 years. It is a manual transmission and had 70,XXX miles on it when I got it. It now has 100,XXX.

I have had NO problems with the car. I perform all my own repairs if needed and my maintenance. I am an ASE certified technician and know my way around a Nissan. This is BUGGING me. It all started after an accident. A lady hit me at stoplight, and bent my front bumper support. The body shop welded on the frame and shorted out all 3 bank 2 (driver cylinders) ignition coils. They sent my car to Nissan and the Dealer replaced the 3 coils and all 6 spark plugs. The body shop kept my car for a month with my coils bad and didn’t tell me until they HAD to. They took it to local shops tying to fix it. When I asked about my car, they said they are sending to Nissan and I would have it back in a week. Nissan told me that the driver side cat was soon to fail, and it did. I don’t know if it was because of fuel dumping into it because of the coils not working or what. It slowly became more clogged, and then dislodged and wedged in my muffler. I know have a true duel X pipe exhaust.

I read about the passenger side valve cover problem with the PCV system and my problems fit the description I saw others with. I replaced it with a new Nissan Cover and gaskets and the problem didn’t change. The throttle body also has some carbon build up but not major. I'm wondering if the Driver side is clogged up. Or the drains on the driver head are clogged and it is over filling with oil and the over flow is spilling down the valves. Could I have had part of my catalytic converter sucked in that bank and scared the walls?

I use Mobil1 10-30 High Mileage and a Mobil1 Filter on EVERY OIL Change since the day I have owned the car.

I have tried to include as much information as I could. I need help as to why this is happening. If I can answer any questions if I left something out, just ask. Any Ideas Guys?

davidv

iTrader: (2)

That is 1 quart of oil every 60 miles. Surprised that the car even runs.

Quamen

iTrader: (14)

Bad rings?

Mrz1985

Runs great, just looks like I'm doing a James Bond Get-A-Way move.

Mrz1985

I'm not sure, I'm trying to find out.

davidv

iTrader: (2)

Oil consumption means, of course, that you are burning oil inside the compression chamber. There is no other diagnosis.

Mrz1985

Yes, I fully understand that I have oil in my chamber. I'm am trying to determine where or what is causing it so that I may repair it.

nkohler

iTrader: (16)

I am not saying this is the issue, but just giving my experience.

One day without any change my car started smoking a good bit. I was burning 1qt around every 150 miles. I took the car to nissan since it was under warranty, and after a lot of run around, they did a leak down test and found 50% leak in 3 cylinders. Motor replaced under warranty.

Mrz1985

Thank You for your input sir

scotts300

iTrader: (46)

You had me at "I lose about 2.5 Quarts of oil in a short 150 miles."

I'd get that leakdown done asap.

Quamen

iTrader: (14)

Do a leak down test.

Lee R

iTrader: (10)

Your cylinders are shot and you are getting all of that nice oil blowby. Compression test won't tell you that. Get a leakdown for sh*ts and giggles but it is short block time for you.

superchargedg

iTrader: (4)

A big plus one on this.

Mrz1985

That may be the case. If the coils went out and the fuel was being injected in. Maybe it did wash the walls, but I don't think I would have such good compression and fuel economy as I have?

Mrz1985

That may be the case. If the coils went out and the fuel was being injected in. Maybe it did wash the walls, but I don't think I would have such good compression and fuel economy as I have? If it was blowby past the rings I would see pressure out of the valve cover when I remove the PCV valve right? I don't. Its so odd to me.

Mrz1985

Would a CLT show me oil control rings?

Quamen

iTrader: (14)

WTF?

Your certified?

Jarred@Z1

iTrader: (4)

^ ya what? although it is just a written test of how well you memorize not a gage of how good you are with cars....

laser24

sounds like a blown headgasket to me.

Mrz1985

995 of the time a head gasket will blow on one, or 2 adjoining cylinders. If it was bad enough to happen to all 3, I would have lower power, mileage, and probably lose coolant also.