I really didn't wanna make a new thread but I've looked everywhere and I haven't seen anyone with my problem...

So here it goes, I have a 2003 g35 coupe with about 117xxx miles on it. Ive had that infamous oil burning problem that seems a lot of other g owners have had. I tested it and it seemed like I was burning about a liter of oil every 500+ miles. I switched to 10w40 oil and it seemed to help the problem a little. But I do stay on top of my car oil and make sure that it's where it needs to be. Recently my car went on limp mode and it threw out the p0300 (engine misfire) I changed all the spark plugs and it threw out the p0303 (cyl 3 misfire) also when I changed the spark plugs all seemed normal except for cyl 3 which looked all blacked and had some clump to it. I've cleaned the MAF, checked to see if it was the ignition coils by switching cyl 3 and cyl 5 but it still threw the cyl 3 misfire.

I've looked around and had some say that it could be the cat but I don't think it would throw out the cyl 3 misfire code if it was the cat???

I've drivin the car on limp mode cuz it's my only means of transportation but when I looked at the mpg it went down to 8 miles per gallon, idk if that helps

I'm just really trying to look for more options here before I go out and by a new engine...

 

sounds to me like the valve cover seals. fairly common problem from reading on these forums.

 

Take out spark plug #3 and see how it looks now. Cylinder 5 on my car was leaking oil through the valve cover, I just put a bunch of RTV around the seal. Not sure if it fixed it, since I haven't checked, but that might be a cheap fix. Other things I would try are:

compression test
leak down test
swap out fuel injector

 

Was your car on limp mode when your cylndr 5 was leaking? If so did it turn off when you sealed it??

Yeah I had another person tell me it could be the fuel injectors. Gonna do that very soon and hope for the best

 

You've got fewer miles than I had on my previous 06 G35 6 speed manual that had 171796 miles when I traded it in for my present 2012 G37S

Instead of "I don't think" and considering "a new engine", why don't you just pay for a professional Infiniti dealer diagnostic fee prior to making any decision?

My 06 very often would use a qt of oil per 1k miles and it ran like new when I traded it it.
I decided not to spend a few thousand dollars on needed repairs such as brakes, headlight ballast and a few other items.

You have a soon to be a seventeen year old vehicle so take that fact into consideration on how much $$$ you are going to spend on it and what it is worth if it were involved in an accident that was not your fault and totaled a day after you spent $$$

Just my $.02

Telcoman

 

No, it was a minor leak and I didn't have performance issues. I'd try swapping fuel injectors.

 

for misfires its either the ig coil or spark plug. if u say u changed out the spark plug and issue persists then its the ignition coil. go with oem

 

OP the one thing I can think of that hasn't been brought up yet is did you check the gap of the replacement plugs. Lots of people just assume new plugs are gapped correctly right out of the box and while that's common not all are. Check the gap on all of your plugs and I wouldn't be surprised if you have one or more that are off.