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Jay
Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 18725
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
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I have a 2009 Nissan Maxima, with 96k miles; I've owned it

Customer Question

Hi! I have a 2009 Nissan Maxima, with 96k miles; I've owned it for last three years. I use premium gasoline, and 5W30 for oil changes. It's a V6 with a VQ35DE engine. Within the last month, blueish/white smoke has been coming from the exhaust... A LOT of it! It's always present on initial start-up, but if I start the car every couple of hours or so, it's still present, but not billowing and suffocating. It also is seen when accelerating on an incline, or accelerating around a right hand turn (yes, only when turning right, not left...?!). HOWEVER..... On initial start up and drive, if I maintain speed of 35 or under (as if I were in 3rd/4th gear if I were to be driving a stick shift), there's never any billowing exhaust smoke at any point: turning, acceleration, etc, except for initial start-up. BUT if during the same "trip," I advance past 35ish MPH, to say, 65/70 on the interstate, and then slow back down off of the interstate, I get all the smoke as usual, as if my car is irritated that I went above 35MPH ;) So even if I slow down to and maintain that lower speed, I still get the smoke bc I had previously been driving at a higher speed. So that's the info on the smoke.
Here's what we've done so far: 1.) taken it to several mechanics; performed a compression test that showed good numbers for all six cylinders, with no variance between them; a leak down test, with great readings and nothing to indicate issues with valve stem seals and/or piston rings; replaced the PCV Valve; replaced spark plugs; obviously have maintained on oil changes! No coolant leak, checked several times. It's definitely consuming a ton of oil bc it's burning it, so we monitor that very frequently, almost daily. The car has never overheated, at least not in the last three years of my ownership. When I purchased the car, the CARFAX was clean. My car has shown no signs of any neglect in maintainence, and hasn't had any major repairs that have needed to be done, prior to this asinine situation! (I know, nothing about this makes ANY sense!!) Here's what puzzles me: when removing the intake manifold yesterday to do the leak down test, we noticed a considerable amount of oil in it!!! Like I said, we had just replaced the PCV. However, the oil seems to be coming/leaking from the PCV and into the intake.... What in the world is going on here?! Helpppppp 😩
Submitted: 9 months ago.
Category: Nissan
Expert:  Jay replied 9 months ago.

Hello my name is ***** ***** thank you for your question.

With this oil consumption issue, it can cause the smoke. How many miles are on the car and are you the original owner?

Customer: replied 9 months ago.
Those were the first things I covered: 96k, and I'm the second owner. I've had the car for the last three years :)
Expert:  Jay replied 9 months ago.

How many miles were on the car when you got it?

Customer: replied 9 months ago.
Around 50k
Expert:  Jay replied 9 months ago.

Did the original owner provide you with maintenance records?

Customer: replied 9 months ago.
I bought it from a dealership, and there were no records that came with it. In three years, this is the very first issue I've ever had :/
Expert:  Jay replied 9 months ago.

The reason I am asking is cause if they did not maintain it, it could develop sludge in the valve cover PVC channel. So it would act like the PCV valve is stuck closed not allowing the crank case to vent. If the crank case can't vent, it will burn oil.

If it's not the valve cover, valve seals are not what normally go. It's the oil rings that normally cause this.

How is the oil level? when doing a oil change on your car it should only take 4 quarts.

Let me know..

Customer: replied 9 months ago.
It takes the normal amount of oil when doing an oil change. Just replaced the PCV valve. And the leak down test gave no indication of faulty seals or oil/piston rings.
Expert:  Jay replied 9 months ago.

Remember when you are doing a leak down, it is testing the compression rings. Not the oil rings. What normally happens is one of two things to the oil rings. Either there is contamination from a bad catt converter or the oil rings oval out allowing oil to pass as the piston goes up and down which allows oil to burn in the cylinder.

Expert:  Jay replied 9 months ago.

I normally would try replacing the PCV valve like you did, and the Valve cover. So I know the PCV channel is clear. If I still experience smoke and a oil consumption issue, the issue is more involved into the Engine, and is most likely the oil rings. That is what normally causes the oil consumption.

You want to inspect the top part of the catt converters when you start taking the engine apart ( if you go that route ) to see if they are broken up on top. If broken up, the debris of the catt gets sucked into the engine and when mixed with the engine oil it becomes a lapping compound which eats away the oil rings.

Other wise, the oil rings are oval'd and that is what is causing the oil to pass the oil ring so oil can enter the cylinder.

Do you have any more questions on this?

Customer: replied 9 months ago.
A leak down test definitely tests the oil/piston rings....
Expert:  Jay replied 9 months ago.

When you are doing a leak down test, the compression rings of the piston is what you are applying the air pressure against. The oil rings are on the bottom. How can it test that ring? The only way is if the compression rings were bad

Customer: replied 9 months ago.
According to the shops I've been to around here, and the research I've done, all day it's piston rings being tested. I don't want to get stuck on that though :)) please tell me more about the catalytic converter, and how it would be the source of oil found in intake manifold, and the source of heavy smoke from the exhaust! If it's not one thing, it's literally another :(
Customer: replied 9 months ago.
all say, not all day, sorry!!!
Customer: replied 9 months ago.
Also, my car has never backfired, and no engine lights have come on. When I took it to Nissan, they said they scanned for codes and nothing came up, so they were assuming valve seals or rings being the problem.
Expert:  Jay replied 9 months ago.

Yes it is testing the compression rings of the piston. But the oil rings sit at the bottom of the piston. So when the piston is going up and down, oil will seep past the oil ring and ride along the cylinder wall and pass into the cylinders and burn. If you do a compression test, if oil is in the cylinders you will find compression to be higher than normal.

As for the catt converter. The top of the catt can break up. Most of the time from low octane fuel. So part of the damage could have been done by the previous owner. So if the top of the catt is broken up, when it gets sucked into the engine when mixed with the oil it becomes a lapping compound. When this happens this becomes a cancer for the engine cause it eats away the metals of the oil rings and all other metal components. Normally starting with a oil consumption issue, then could result in a head gasket issue.

If you are going to go as far as to do valve seals, you might as well have the rings checked as well.

I know this is not the answer you want to hear. Most manufactures. We set the oil level and mark it. then ask the customer to return with in 1k miles after marked. Depending on how much oil consumption, it tells us whether or not it's more of a mechanical issue, or possible crack case venting problem.

Do you have any more questions on this?

Customer: replied 9 months ago.
The numbers for both the leak down and compression tests were good.
I would love to have the piston rings looked at, but I can't find anyone that will do it. They've all been very quick to advise me to just put in a new/used engine. Trust me, if I had 5k, I'd pay off my loan and get a new car, not a new engine for it :/ so what should my next course of action be? Replacing converter?
Expert:  Jay replied 9 months ago.

Do you have those readings and results? I am more or less looking for the compression readings.

Customer: replied 9 months ago.
All cylinders read between 185 and 195
Expert:  Jay replied 9 months ago.

That is above the maximum range which is even more of a indication of a oil ring issue.

Max range is 185. Which it would never be at 185 with 96k miles. I would expect to see 160 or so.

Expert:  Jay replied 9 months ago.

When doing a compression test, if you add a little oil, it will raise the compression.

Customer: replied 9 months ago.
both wet and dry were done. Why would a higher than max number indicate an oil ring issue?
Expert:  Jay replied 9 months ago.

Which would give you those type of readings. So the person doing the compression test should have been able to identify that for you.

To do a ring job on this engine it would cost you more than if you were to replace the engine.

Expert:  Jay replied 9 months ago.

The oil in the cylinder actually seals off the cylinder more which raises compression. There is no need to to a wet compression test unless there was a running issue.

Customer: replied 9 months ago.
decrease in power
Expert:  Jay replied 9 months ago.

Everything you are saying and providing me is pointing towards rings.

Expert:  Jay replied 9 months ago.

https://dl.dropboxusercontent.com/u/105565483/Piston%20Rings%20%281%29.png

If you look at the ring layout. The oil ring is all the way at the bottom of the piston.

Expert:  Jay replied 9 months ago.

Do you have any more questions on this?

Customer: replied 9 months ago.
there's no way to check the oil rings?
Expert:  Jay replied 9 months ago.

Not with out taking the engine apart to check them.

the way you would check the oil rings is to break down the engine and then remove the rings from the pistons and place them in the cylinders and measure them with a feeler gauge.

https://dl.dropboxusercontent.com/u/105565483/piston%20ring%20check.jpg

Customer: replied 9 months ago.
No one wants to do that around here though, and it's frustrating.
Expert:  Jay replied 9 months ago.

a used engine is around 2100. With around 13 hours labor. So all together around lets say 3500. To take the engine apart to check rings is 20 hours labor and if found the engine is no good, then you are looking at 2100 again with a additional 10 hours labor.

Expert:  Jay replied 9 months ago.

They don't want to in your best interest and theirs.

Expert:  Jay replied 9 months ago.

Do you have any more questions on this?

Customer: replied 9 months ago.
Is there any temporary fix to this? Let's say it's not the rings, but the converter or something else that's getting oil into the intake manifold. Just until I can get my action plan together? And by fix I mean, get the smoke to stop
Expert:  Jay replied 9 months ago.

You can try adding stop smoke from your local auto parts store. That gums up the system a little which can temporarily seal the system and cut down or stop the smoke.

That is the best I can suggest for you.

If you have any more questions on this, please feel free to ask.

If not, and you're satisfied with my help, please Rate me. That is how I get credit for my work.

I hope I have provided you with Excellent Service.

Thanks Jay!

Expert:  Jay replied 9 months ago.

Don't forget to Rate me if your Satisfied with my help.

Expert:  Jay replied 9 months ago.

Do you have any more questions on this?

Expert:  Jay replied 9 months ago.

Hello?