[Enzo3440]

2007 frontier 4.0 91k
-driving fine Tuesday, Wednesday morning running a bit rough my gf noticed while driving, Wed afternoon absurd amounts of smoke coming from exhaust
-smokes bad when idling, accelerating, after it’s warm, all the time and gets absurd level smoke when revving
-white smoke, but smells more like oil than coolant
-puddle under tailpipe after revving,pretty watery

tests
-did block test and radiator is free of exhaust gas
-exhaust gas was coming from oil fill cap
-coolant looks clean but when running has big bubbles at times
-oil on dipstick looks perfect
-cylinder 5 had a misfire code p0305
-pulled plug#5 and it was oily with build up, all other are good
-installed new injector, no change
-Compression test numbers were good but over 200, however since it’s a ***** I left the plugs in (my thought was I didn’t have a cylinder to cylinder issue and I was focused on 5) I then confirmed 4 and 6 were the same
-I changed the pcv valve, the one in there was for sure bad, no rattle, but still no change. It maybe got better for a minute then back to crazy smoke.
-there seems to be a small oil drip from the exhaust manifold to cat flange on both sides

So it seems the rings, valve seats, and gasket are fine. I have a hard time believing all that smoke and so suddenly could be from valve stem seals. Seems like that would get worse overtime not all at once. Could a wiring issue cause the injector to be stuck open?

 

[busemans]

and number 5 is still oily now that you changed it out? pull it again and check it since you have driven a bit on it. since its oily, i bet its not an injector but i don't know what since your compression check was good.

do a vacuum check and see what it pulls and the swing of the needle. that can tell you if its the stem seals.

 

[Cusser]

James Bond level smoke screen coming from tailpipe

Is OddJob chasing you ?

 

[Enzo3440]

and number 5 is still oily now that you changed it out? pull it again and check it since you have driven a bit on it. since its oily, i bet its not an injector but i don't know what since your compression check was good.

do a vacuum check and see what it pulls and the swing of the needle. that can tell you if its the stem seals.

So I plugged my brake bleed tool into the small nipple on the front of the manifold. Vacuum read 20 but the needle would swing like crazy when blipping the throttle. But I thought it was normal for vac to increase. Could they fail that quickly? And produce that much smoke?

And I haven’t driven it, it wouldn’t be possible with this much smoke. I’m not exaggerating with the title.

 

[Grampy Matt]

bubbles in the cooling system is a classic sign of a bad head gasket

 

[keith56]

One possibility is a clogged oil return passage. The evidence is the #5 plug fouling. Remove the valve cover on that side of the engine right after you have run it for a few minutes to see if oil is pooling around the valve stems in that last cylinder. The oil return drains will be on the exhaust side, usually in the corners but I have seen them in the center, exhaust side (Fords).

 

[busemans]

So I plugged my brake bleed tool into the small nipple on the front of the manifold. Vacuum read 20 but the needle would swing like crazy when blipping the throttle. But I thought it was normal for vac to increase. Could they fail that quickly? And produce that much smoke?

And I haven’t driven it, it wouldn’t be possible with this much smoke. I’m not exaggerating with the title.

vacuum will swing wildly when you give it gas because you lose vacuum when you open the throttle plate. thats normal

Quick Tech: How to Read a Vacuum Gauge to Pinpoint Engine Problems - OnAllCylinders

 

[busemans]

check what keith says.

 

[Enzo3440]

One possibility is a clogged oil return passage. The evidence is the #5 plug fouling. Remove the valve cover on that side of the engine right after you have run it for a few minutes to see if oil is pooling around the valve stems in that last cylinder. The oil return drains will be on the exhaust side, usually in the corners but I have seen them in the center, exhaust side (Fords).

Ok thanks I’ll check that today and report back.

 

[Enzo3440]

One possibility is a clogged oil return passage. The evidence is the #5 plug fouling. Remove the valve cover on that side of the engine right after you have run it for a few minutes to see if oil is pooling around the valve stems in that last cylinder. The oil return drains will be on the exhaust side, usually in the corners but I have seen them in the center, exhaust side (Fords).

I think I can see the passage and it looks clear.
Take a look at plug #5 it’s bad. Also lots of oil in the intake. Not sure what that shmutz is on the cam though. Also found oil on the valve cover screw so either bad gasket there or tons it in the valve-train.

 

[CT_Nismo]

If #5 is causing all your smoke, you can back check it by taking off the coil firing wire. If you run the engine and see no smoke, then for sure it is #5 cylinder. How the oil got in there is a mystery. But it will be costly to fix no matter what the cause is.

 

[keith56]

Your head looks really clean. The oil under the cam lobes is intentionally trapped there to keep the lobes lubricated all the time. I don't see the return holes but I would use something thin, long and flexible like an tie wrap used for electrical cable bundles. Poke it down any suspected drain holes to see if it goes down into the oil pan.

Usually the drains get clogged by oil sludge, but I don't see any evidence of sludging on your head.

 

[Enzo3440]

Your head looks really clean. The oil under the cam lobes is intentionally trapped there to keep the lobes lubricated all the time. I don't see the return holes but I would use something thin, long and flexible like an tie wrap used for electrical cable bundles. Poke it down any suspected drain holes to see if it goes down into the oil pan.

Usually the drains get clogged by oil sludge, but I don't see any evidence of sludging on your head.

Yeah everything looks good, I’ll check that. Any other ideas? Can I do compression test with valve covers off?

 

[Enzo3440]

Your head looks really clean. The oil under the cam lobes is intentionally trapped there to keep the lobes lubricated all the time. I don't see the return holes but I would use something thin, long and flexible like an tie wrap used for electrical cable bundles. Poke it down any suspected drain holes to see if it goes down into the oil pan.

Usually the drains get clogged by oil sludge, but I don't see any evidence of sludging on your head.

So I cranked the car a bunch with the valve cover off when doing another compression test and the oil is draining perfectly. Compression on all cylinders 234-240. So it has to be valve stem seals? I do think I noticed exhaust coming up but not exactly sure from where, spark plug or valve.

 

[invasion08]

So I cranked the car a bunch with the valve cover off when doing another compression test and the oil is draining perfectly. Compression on all cylinders 234-240. So it has to be valve stem seals? I do think I noticed exhaust coming up but not exactly sure from where, spark plug or valve.

I think you messed up your compression test. Those numbers are way to high. If it was a bad valve it would only smoke on start up.

https://www.autozone.com/diy/ignition/how-to-do-an-engine-compression-test

 

[Enzo3440]

I think you messed up your compression test. Those numbers are way to high. If it was a bad valve it would only smoke on start up.

https://www.autozone.com/diy/ignition/how-to-do-an-engine-compression-test

Yeah I did exactly those steps. Even valve stem seal?

 

[invasion08]

Yeah I did exactly those steps. Even valve stem seal?

Your compression gauge is broken then.

 

[maineiac]

Your compression gauge is broken then.

or there is oil or other fluid in cylinders, bad carbon buildup in cylinders, sticky exhaust valves. gauge could be correct


ok so getting back to the issue
cyl 5 misfire per code - misfire codes can sometimes call out incorrect cylinders

did you confirm its actually 5 and 5 only by disabling spark on that cylinder and look for any change in the way the engine runs? what happens on all the other cylinders same test...?
do you have a scan tool able to look at fuel trims - if so what are they per bank long and short term?
are you sure the smoke smells oil or could it be fuel? you did say white and not blue tint...

if its fuel smell the issue is most likely the misfire causing a lean condition at the a/f ratio sensors causing the ecm/pcm to drive the other cyl very rich creating white fuel smelling "smoke".

quick note 02 and a/f ratio sensors detect the presence of 02 only, if you have a misfire it looks to the sensors like the exhaust is very lean because the misfire is essentially pumping unused 02 into the exhaust.

 

[invasion08]

or there is oil or other fluid in cylinders, bad carbon buildup in cylinders, sticky exhaust valves. gauge could be correct


ok so getting back to the issue
cyl 5 misfire per code - misfire codes can sometimes call out incorrect cylinders

did you confirm its actually 5 and 5 only by disabling spark on that cylinder and look for any change in the way the engine runs? what happens on all the other cylinders same test...?
do you have a scan tool able to look at fuel trims - if so what are they per bank long and short term?
are you sure the smoke smells oil or could it be fuel? you did say white and not blue tint...

if its fuel smell the issue is most likely the misfire causing a lean condition at the a/f ratio sensors causing the ecm/pcm to drive the other cyl very rich creating white fuel smelling "smoke".

quick note 02 and a/f ratio sensors detect the presence of 02 only, if you have a misfire it looks to the sensors like the exhaust is very lean because the misfire is essentially pumping unused 02 into the exhaust.

Then why is it that high on all cylinders? The way the OP described the smoke leads me to believe it is an oil problem. With out seeing it in person it is hard to tell. Could also be a bad head gasket, but who knows with videos or seeing it in person.

 

[shift_RUSH]

Would a leak down compression test prove useful here?