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Discussion Starter #1
Hey guys. I drive an '02 Sentra SE-R, 134k miles, 5spd, QR25DE. The car was my mother's at ~60k miles, and I drove it occasionally til 120k. Then I got the car, and have been driving it since 120k. I am an aggressive driver...very aggressive. This car has not thrown a single code since it was purchased at the dealership, and has not sputtered or choked one bit since purchased. With all that being said;

I changed my oil a couple of weeks ago, and the other day when I checked the oil it was bone dry. The system was sealed, so I was very confused as to where 4qts of oil went. Today, I went down to Wal Mart, car running fine like always, except my CEL had been on for a week or two (error codes 0031 and 0132). On my way back, I stopped at a stoplight on a 4lane road (rt 1 in Westerly, RI). When it turned green, I decided to race to fourth gear. Out of nowhere, lights flashed in my rearview. Cop pulled me over, told me I gagged him with black smoke, it was pouring out my exhaust. I told him I would drive to a mechanic, and I did. Upon leaving, I put it under a load, and noticed white (oil) smoke coming out.

So, now I know where all that oil went - I burned it. Driving to the mechanics, I pondered why and how I could have burned so much oil so quickly. After all, the car was running smooth!! We got to the mechanics, and wouldn't you know, JUST as I pulled up, my car started puttering, bogging, running very shitty. Had the mechanic look it over, he told me it was an internal problem with cylinder 2/3 (the passenger-side inside cylinder). He told me it was serious -- something like a piston, piston ring, hole in the cyl wall, or valve problem. Compression test showed 20lbs of compression in that cylinder. I started it up, it was boggy, and drove to McDonalds.

Here's where it gets a little weird....When I pulled into McD's, it fixed itself. By that, I mean that the bogging/shit-running stopped. The problem just went away. I was left to ponder what could possibly go wrong to make this happen?!

Upon much pondering, I was sort-of convinced by someone that it could be a piston ring that broke off, went up into the cylinder, got stuck in the valve (holding it open, making it run shitty), and then either got pulled back into the cyl or pushed out of the valve, making it run good again. That also explains the extreme loss of oil, as the oil could have passed through the piston ring area.

With all this being said -- WHAT DO I DO?! I have no (or very little) money. I love this car. I understand that this was my fault, as a result of my arrogant driving, and I have nobody to blame but myself.

Does anybody have any ideas? I am considering selling it, to somebody that could fix it up and use it, or maybe I could buy another QR, swap it out, and do something with the old QR. I Just don't know what to do.

If you have any suggestions, or you'd like to offer me some money for the car, I'm willing to consider anything. I live in Westerly, RI. The car is registered in my name, I have the title, there are no problems with that.
 

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First things first, I didnt see a header on your mods list (as your sig). You do have one installed right? and if so, around what mileage did you install it? and if not.....well, Im sure the problem will be obvious.
 

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Discussion Starter #3
No -- stock header. If that is the problem, what could be done to fix it? Could the cylinder be sleeved and header replaced? Would it be cheaper to buy a used engine?

I really hope someone from 2jR could chime in -- I know they are very experienced...maybe I could swap my motor + cash for one of their QR's that is laying around.

I just have no idea.........
 

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Pretty much what Misternuts posted. There's a sticky on this site that shows some of the recalls that this car has had and the stock header is one of them.
The stock header has what is called the "pre-cat" (catalytic converter) that when the car is driven hard, can break up and get sucked into the engine, scarring the cylinder walls, which in turn causes massive oil consumption.
unfortunately, there are limited solutions AFTER it has happened, but if you do stick with another QR, buy a header and swap it immediately.
 

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sounds like text book precat failure to me :(

the precat and butterfly faq here:
http://www.b15u.com/troubleshooting-support/3623-qr25de-precat-butterfly-screw-faq.html?highlight=precat+faq

im guessing your headgasket could be the problem as well. if you have a lot of internal damage, it may be cheaper and easier to get a whole motor and swap it in. what killed your current motor was lack of oil during aggressive driving. im hoping you read the precat faq and understand why you didnt have 4 qts of oil. this couldve been prevented by checking your fluid levels regularly and getting a catless header.
 

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Check you coolant level, it is probably low. Random misfire and cylinder misfire but no cat code? Maybe your HG gave out. Leave the cooling system pressurized overnight and look into the cylinders the next morning, Cyl 2 and 3 will probably be wet.

HG isn't very expensive or that hard to change, do it yourself and learn a lot. Plus save the car
 

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Hmmm, maybe the ring was stuck then freed itself. Or piece of cat jammed in ring. Check compression again. What were the other cylinders reading? Maybe some seafoam and in oil too and clean it all out. Its running ok now? That could explain fix itself
Just a thought.......
 

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Honestly...it did not fix itself. Its still broke. Your engine ate the cat. You will have a p0420 very soon. If you have a scan tool you can monitor the front and rear o2 sensors.if they are showing the same or roughly the same pattern, that shows the cat isn't opperating. The rear o2 sensors should got flat when fully warm with a nearly constant voltage. That indicates the rear o2 sees a change in NOx and that means cats working.
You need a header ...although its too late. Reguardless of rebuild or used replacement, U NEED A HEADER.
Now the real question is do you spent 2k+ on a qr....or 7k on vq? Lol!

I can't help with the money problem...just know im in the same boat. Bought car for 4k, 107k miles, drove 80 miles and it smoked like a train
 

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Discussion Starter #11
So, I'm guessing that the best way to go would to be to buy a new QR, swap it out, and figure out what to do with my current QR.

What would a used QR cost?
What could (If I could) I sell my current QR for, knowing about the cyl scarring?
How much should I sell the car for as is?
Anyone want to buy a nice sentra? :p
 

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A used qr is around 1800 plus labor around here
 
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