My 2004 I35 (112,000 miles) is going through about a quart of oil every 400-500 miles. There is no dripping on the ground. Sometimes when I start the car white smoke comes from the exhaust. This doesn't happen in the morning really, it's more if I drive the car for a while, turn it off, then restart after it sits for a bit. The smoke comes out for a second or two and that's it. A few times I have noticed the white smoke coming out when I accelerate hard, but that's just a few times.

I have taken it to two shops so far. The first said that one of the spark plugs was dirty/fouled but I forgot to ask which one. That mechanic also said a lot of smoke came out when he rev'd it. He told me he needed to rebuild the engine for $3200. The second mechanic said he found nothing wrong - no smoke, no oil where it shouldn't be. He then wanted to charge $225 to pull the the plugs out of the right bank (side towards the windshield) and boroscope it. I declined.

Today I noticed some smoke come out of the exhaust. When I went to look at it, the smoke was only coming out of the left pipe and some liquid dripped out. The liquid seemed to be water based.

I replaced the PVC valve as a longshot, but that didn't help. I'm thinking of trying to replace the right valve cover in hopes of an inexpensive fix. If I need a rebuild so be it, but I was hoping to try something else out first.

If anyone has ideas for my problem I would appreciate it...greatly.

man.. that sucks. try Lycos engine oil stabilizer??? I don't even know if that would help. water out of tail pipe is normal.
if you have no oil leaks at all , and you loose oil then the smoke should be more of a blue color.
(check your oil sending unit . bottom on pass side by the oil filter. take the plug of of it and see if it is covered in oil, also check your coolant maybe the oil goes there????)

If I recall correctly, the 2002-2004 I35 and Maxima had an issue with oil consumption, which usually led to having the motor rebuilt. I'll try to find some more detailed info, but it shouldn't be using that much oil between oil changes at all.

Are you the original owner? What is your oil change interval (OCI)? Were you consuming oil before and just got worse?

Oil consumption on the VQ35 has been attributed to leak on right bank Valve Cover, loose piston rings, bad design on Pre-cat as well as routing of Positive Cranking Ventilation (PCV). I've seen a small amount of oil leak in Cylinder 5 when I did plug change in the 06 M35 at 90K miles (still waiting for a re-designed valve cover before replacing since I have minimal oil consumption). Some owners have reduced oil consumption by reversing the PCV flow from the original Front Valve Cover to Rear Valve Cover. Looser piston rings is one way to increase power without increasing engine size. But this can cause oil to go past the rings and partially burned during combustion. Changing from 30 weight to 40 weight oil may reduce the blow-by.

I'm not sure how much overlap in Exhaust and Intake stroke in the VQ35 engine. But this is done to reduce engine temp and lower NOx emission. However, it creates a negative pressure in the Pre-Cats. Oil going to the 'cat' can prematurely damage the honeycomb, creating particles. Due to cam overlap, these particles can get ingested into the engine, sand-blasting the cylinder walls causing more oil leaks... and the cycle becomes vicious, eventually damaging the engine.

A33 wrote:If I recall correctly, the 2002-2004 I35 and Maxima had an issue with oil consumption, which usually led to having the motor rebuilt. I'll try to find some more detailed info, but it shouldn't be using that much oil between oil changes at all.

Yeah, I've read some of the issues online. I'm hoping getting a new valve cover does the trick (which I've never done, but I'm going to try!). If I need a rebuild, is $3200 reasonable?

I'm just confused where all the oil is going. I did see it smoke last night when I accelerated onto the freeway, but I don't see that all the time.

qwertyz wrote:man.. that sucks. try Lycos engine oil stabilizer??? I don't even know if that would help. water out of tail pipe is normal.
if you have no oil leaks at all , and you loose oil then the smoke should be more of a blue color.
(check your oil sending unit . bottom on pass side by the oil filter. take the plug of of it and see if it is covered in oil, also check your coolant maybe the oil goes there????)

Do I need to drain the oil and coolant if I do that? I read that somebody replaced the gasket where the oil filter screws in to investigate a leak. Is that the same thing you are talking about?

loystock wrote:Are you the original owner? What is your oil change interval (OCI)? Were you consuming oil before and just got worse?

Oil consumption on the VQ35 has been attributed to leak on right bank Valve Cover, loose piston rings, bad design on Pre-cat as well as routing of Positive Cranking Ventilation (PCV). I've seen a small amount of oil leak in Cylinder 5 when I did plug change in the 06 M35 at 90K miles (still waiting for a re-designed valve cover before replacing since I have minimal oil consumption). Some owners have reduced oil consumption by reversing the PCV flow from the original Front Valve Cover to Rear Valve Cover. Looser piston rings is one way to increase power without increasing engine size. But this can cause oil to go past the rings and partially burned during combustion. Changing from 30 weight to 40 weight oil may reduce the blow-by.

I'm not sure how much overlap in Exhaust and Intake stroke in the VQ35 engine. But this is done to reduce engine temp and lower NOx emission. However, it creates a negative pressure in the Pre-Cats. Oil going to the 'cat' can prematurely damage the honeycomb, creating particles. Due to cam overlap, these particles can get ingested into the engine, sand-blasting the cylinder walls causing more oil leaks... and the cycle becomes vicious, eventually damaging the engine.

I am the second owner. I don't know anything about the first owner. I bought it with about 87,000 miles on it and have had it a little over a year. Jiffy Lube had one oil change on record and full synthetic was used, so I've been using full synthetic. I change it around 5,000 miles. I didn't notice any problems for about six months, then my oil light started to blink at times and I got a camshaft positioning sensor error. After an oil change, the car ran much better and the error cleared for a while until, I'm assuming, the oil got low again.

I don't know a lot about cars, but I am mechanically inclined. I don't understand what the pre-cats are and I don't know how to reverse the PVC flow. Is that something that is not too hard to try?

kasteelfreak wrote:

qwertyz wrote:man.. that sucks. try Lycos engine oil stabilizer??? I don't even know if that would help. water out of tail pipe is normal.
if you have no oil leaks at all , and you loose oil then the smoke should be more of a blue color.
(check your oil sending unit . bottom on pass side by the oil filter. take the plug of of it and see if it is covered in oil, also check your coolant maybe the oil goes there????)

Do I need to drain the oil and coolant if I do that? I read that somebody replaced the gasket where the oil filter screws in to investigate a leak. Is that the same thing you are talking about?

no i am not talking about oil cooler (where the oil filter screws in)
i am talking about oil sendin unit (sensor) right by the oil filter and no you dont have to drain all the oil out, even if you change the sensor you will lose about a quart (so up to you)

The Pre-Cats and Main Cat (3-way catalytic converter) consists of rare and expensive metals (platinum, palladium and rhodium) which oxidizes/reduces harmful engine exhaust (HC, CO, NOx, etc) into less harmful gases (H2O vapor, CO2, etc).

Pull at least of the plugs from Bank 1 (near firewall) and check for presence of oil. Have a compression check and do visual inspection of the oil pan-filter area. Disconnect the Pre-Cats and check for particles/damage. In the mean time, check your oil level at least once a week and top off as required.

Engine rebuild/change is really expensive so ask around before you commit.

loystock wrote:The Pre-Cats and Main Cat (3-way catalytic converter) consists of rare and expensive metals (platinum, palladium and rhodium) which oxidizes/reduces harmful engine exhaust (HC, CO, NOx, etc) into less harmful gases (H2O vapor, CO2, etc).

Pull at least of the plugs from Bank 1 (near firewall) and check for presence of oil. Have a compression check and do visual inspection of the oil pan-filter area. Disconnect the Pre-Cats and check for particles/damage. In the mean time, check your oil level at least once a week and top off as required.

Engine rebuild/change is really expensive so ask around before you commit.

Thanks, I'll give it a look.

You could also look for a VQ35 engine @ an auto recylcer from a totalled I35 or Maxima. You'd probably do the engine swap for about 2/3 the cost of a rebuild. It' is a gamble either way.
If you really like the car and would like to keep it for another 5 years +, then rebuild it. As long as the rest of the car is in good to great condition, that is.
If that's the route you choose, I'd do a lot of research to find a well respected engine rebuilder that specialises in Nissan.

I am having same issue, burn a quart oil every 400 miles. Car runs great, good power. Same issue with smoke coming out of exhaust when car restarted after sitting for half hour. I have replaced both valve covers and pcv valve. PCV replacement greatly reduce smoke from exhaust to the level it is now. And the valve cover replacement did stop small leak I was having onto garage floor. Now the car runs great but still plagued with very high oil consumption.