Why am I burning oil?

[Vsicks Pathy]

Is it still knocking?

[OR99.5Speed]

Err, hate to be the bubble burster, but most of the top of the motor has to be removed, incl intake manifold, exhaust manifold and heads, then the heads/valves inspected (repaired), rings installed and everything reassembled. does this sound like a 3-4 hour job ? Sorry, no...

 

I just had a 4cly Honda redone. Head gasket, rings, cylinder honed, head milled, new valves, seats and guides (+full tune up)for $1800... Thats an easy 1 bank 4 banger, not a V6...

 

B

Hmmm...thanks for the advice!

 

After talking to Dad it seems the best thing to do is to suck it up and get the engine rebuilt. I remember from my 4.0 Jeep days that if you were going to tear into your engine you may as well get a 4.7 stroker kit. Since the VG was used in the 300ZX of the 80's there has to be somewhat of an aftermarket, and the 3.3 can't be too much different.

 

My question is: Since a mechanic is going to be replacing the internals or at least going to be in the vicinity is there any performace internals such as pistons, etc. that would give more performance to the gutless 3.3?

[OR99.5Speed]

Is it still knocking?

No, there is no knocking. When the engine is three quarts low (I know, I know) you can hear a tapping while sitting inside the truck. Obviously the tapping frequency increases with revs. When the engine has the normal amount of oil it seemingly runs fine, possibly with a slight loss of power, but at the same time I'm not beating on it in this condition. The engine makes the normal amount of noise with the normal amount of oil.

 

I'm just wondering what caused it. I've never heard of an engine going from no consumption to 1 quart/100 miles.

[Mr. Pickles]

I personally wouldn't risk driving at all really, especially on a 600 mile trip where you're gonna go through 6 quarts of oil. You're running the risk of breaking down somewhere along the way, you'll probably be looking at replacing the cat and O2 sensor if you drive it burning all that oil, plus what happens if you do actually make it to school? Now you're 600 miles from home and still have a screwed motor.

 

As for the motor swap to a different size, I'm pretty sure you're looking at some custom swaps of parts. There are posts on here talking it through, but I can't recall anybody actually going attempting it. Of course it CAN be done, but it sounds more like you're looking for a straight drop in, plug-n-play install.

 

So, my vote would be to stop driving it around risking further damage or issues while you're guessing and asking for input, and actually check it out/get it checked out to see what the problem is.

[oilman]

I'm just wondering what caused it. I've never heard of an engine going from no consumption to 1 quart/100 miles.

running 3 qts low for 800 miles is what caused it.

It you are just now noticing the black mark above the exhaust pipe then I would say for syure that you didnt start burning that much oil until you heard the loud knocking and went to your mechanic.

 

You might be able to get a crate reman engine instead of rebuilding your engine for close money. A factory reman is always preferable over having someone do it for you. Those engines are built in a factory with all the necessary tools by someone who does several of them a week, as opposed to the local shop who rebuilds maybe a couple engines a year, and maybe doesn;t have the right tool handy. I dont know about availability of the 3.3 as a reman, but I'd check into it before I had someone do it.

 

As to your earlier question about oil weight that will last longer, go heavier! like 20-50wt. Unless you live in cold conditions, in tha case just keep alopt of oil handy. and as mentioned there are lots of additives to slow oil consumption.

[OR99.5Speed]

running 3 qts low for 800 miles is what caused it.

It you are just now noticing the black mark above the exhaust pipe then I would say for syure that you didnt start burning that much oil until you heard the loud knocking and went to your mechanic.

 

You might be able to get a crate reman engine instead of rebuilding your engine for close money. A factory reman is always preferable over having someone do it for you. Those engines are built in a factory with all the necessary tools by someone who does several of them a week, as opposed to the local shop who rebuilds maybe a couple engines a year, and maybe doesn;t have the right tool handy. I dont know about availability of the 3.3 as a reman, but I'd check into it before I had someone do it.

 

As to your earlier question about oil weight that will last longer, go heavier! like 20-50wt. Unless you live in cold conditions, in tha case just keep alopt of oil handy. and as mentioned there are lots of additives to slow oil consumption.

Cool, I appreciate the help! 20w-50 sounds like a good idea.

 

If I were to rebuild the engine I would have to find a good mechanic who could do it (and I don't know any at all) so it seems like it would be somewhat of a crap shoot. I was thinking either factory rebuilt or a used engine out of a wrecked vehicle. There seem to be more people wrecking Xterras than Pathfinders! I wonder if an Xterra engine would fit right in? Maybe use an Xterra ECU? I know that when the Xterra got the Supercharger in 2002 the hood had to be raised to accomodate the supercharger. Wonder if the Pathfinder hood is tall enough?

 

Here is an Xterra Supercharged engine, don't know if it would work or fit:

Xterra Engine

 

Regular Xterra VG33E, says it will fit Pathfinder:

Xterra VG33E

 

VG33E used engine:

VG33E

[OR99.5Speed]

I personally wouldn't risk driving at all really, especially on a 600 mile trip where you're gonna go through 6 quarts of oil. You're running the risk of breaking down somewhere along the way, you'll probably be looking at replacing the cat and O2 sensor if you drive it burning all that oil, plus what happens if you do actually make it to school? Now you're 600 miles from home and still have a screwed motor.

 

As for the motor swap to a different size, I'm pretty sure you're looking at some custom swaps of parts. There are posts on here talking it through, but I can't recall anybody actually going attempting it. Of course it CAN be done, but it sounds more like you're looking for a straight drop in, plug-n-play install.

 

So, my vote would be to stop driving it around risking further damage or issues while you're guessing and asking for input, and actually check it out/get it checked out to see what the problem is.

It sounds like you are right on all counts. I'm not too worried about the cat and O2 senson, they have 103k anyways. I can always hollow the cat out in 2 minutes if I need to on this one. But sounds like a good idea not driving. If I don't make it to Indiana for a meeting on Sunday then I can't attend school in the spring, so that sounds waaay too risky.

 

I'm asking about stuff now so I can see what my options are and how much I should be expecting to pay for a full engine rebuild. If I rebuilt it I would want a VG34 stroker, but then I imagine that's gonna cost some serious money. I really really wish that Xterra motor would drop right in but I'm not the pioneering type when it comes to cars. I also wish the 2001 Pathfinder engine would work, but the same issue with OBDII and ECUs would be present.

 

What is the normal compression for a good engine? I have an appointment at the dealer at 3pm today to get a compression test. I'll let everyone know what the results are.

[k9sar]

for your engine, the compression pressure in psi is 173. Minimum of 128 but there should not be a difference of more than 14psi between any 2 cylinders.

 

if one or more cylinder is low, pour a little engine oil in through the spark plug hole and recheck it.

 

If compression improves, rings are probably worn or bad

If compression stays low, could be a stuck valve or one seating improperly

If compression in any 2 adjacent cylinders is low and oil doesn't help, you have a head gasket leak

Edited January 4, 2006 by k9sar

[88pathoffroad]

If my Pathy engine got fooked up like yours because of a Firestone problem, first I'd get a lawyer. Then I'd go back to the Firestone I went to , back it up to the first open bay, put it in Neutral and floor it. Let 'em eat smoke. Bastards.

 

Honestly, I don't know why you're not looking into suing Firestone. You seem content to just lie there and take it up the butt while they caused thousands of dollars worth of damage to your truck by not doing the maintenance properly...

[OR99.5Speed]

Honestly, I don't know why you're not looking into suing Firestone. You seem content to just lie there and take it up the butt while they caused thousands of dollars worth of damage to your truck by not doing the maintenance properly...

Because I can't prove that it was Firestone. I don't even know that it was Firestone, but they were the last ones who changed the oil. I have my oil change reciept and the oil change was from before Thanksgiving break. I didn't notice anything weird, didn't notice any oil burning, didn't hear anything wrong until I found I was three quarts low. I just don't see how much blame I can put on Firestone. I mean, maybe they underfilled it by a few quarts and then I drove on it and it burned up a quart without me noticeing and sludged up the engine? I'll talk it over with Dad but we just have no proof that they screwed it up.

 

Well, so I went to the dealership who I trust and who is really honest today. I talked to the service advisor about my situation. Thanks K9sar for posting the compression #s but we decided not to even do a compression test, as there is no point in checking the compression of an engine that 1)will be junked and be replaced by a used engine or 2) be rebuilt and possibly not be as good as a used engine but will be equally expensive. We took off the oil filler cap and shined a flashlight into the valvetrain, the sludge was one of the worst he has ever seen. On a scale of 1-10 of sludge, mine was an 8 or 9 but doesn't knock. I don't think I'll be driving up to Indiana because it's such a crap shoot.

 

I want to get a used engine out of an Xterra off of Ebay one of the ones I posted a link to. That seems the best option.

 

What do you think is the going price of taking out my engine, stripping the accessories, and putting the accessories onto the new engine? Maybe another $1000? Is that all that is involved? Apparently making an Automatic tranny Xterra motor into a Manual Pathfinder motor is a real PITA.

 

Thanks!

Edited January 4, 2006 by OR99.5Speed

[OR99.5Speed]

UPDATE:

 

I took the Pathfinder into a reputable shop today, worried that I would need a new engine. I told them to see what the problem was, hoping I didn't collapse a piston ring. After two arduous hours, here is their findings:

 

"Customer states vehicle smokes when accelerating -check and advise. Perform compression test if necessary.

 

We found engine oil is fuel contaminated, fuel pressure normal. We found Mass Air Flow sensor 118 gr/sec on snap acceleration (Known good meter from Infiniti QX4 on lot 52.89 reading). Engine going rich on acceleration causing overfuel, contaminating oil, causing burn. Plugs are OK (covered in soot but should clean with normal use). PCV valve getting clogged, compression OK at this time. Recommend Mass Air Flow sensor, PCV valve, change oil & flilter & monitor oil consumption.

 

Mass Air Flow sensor ($550 parts & labor)

PCV valve ($45 parts and labor)

Oil Change ($25.27)

 

I'm just getting a dino oil change because I'm gonna Auto RX it to help with the sludging. Expensive sensor, dealer cost is $390!

[Precise1]

Glad it was not the motor, but there is still the mystery of the low oil... watch it closely for a while... $550 for MAF ??? WTF ??? I'd be junkyarding it !!

congrats on it being less of an issue than you thought !!

 

B

[OR99.5Speed]

Glad it was not the motor, but there is still the mystery of the low oil... watch it closely for a while... $550 for MAF ??? WTF ??? I'd be junkyarding it !!

congrats on it being less of an issue than you thought !!

 

B

Thanks B!

 

What I"m hoping the low oil was was that since fuel was mixed with the oil by running pig rich that the oil was combustible. I will be keeping a close eye one the oil level though. And it did compression check just fine.

 

I also will be Auto RXing it, just curious if anyone has tried it.

[mws]

Hmmm.... Methinks it will be a borderline miracle if there isn't some kind of damage from running with that low of oil...

 

Did they do a compression check and a leakdown test?

 

If not, I highly advise doing so before spending any $$$ on the MAF.

[OR99.5Speed]

Hmmm.... Methinks it will be a borderline miracle if there isn't some kind of damage from running with that low of oil...

 

Did they do a compression check and a leakdown test?

 

If not, I highly advise doing so before spending any $$$ on the MAF.

They did a compression test and it was okay, no leakdown test, which in hindsight should have been performed.

 

I have a 600 mile drive tomorrow, so I will monitor the oil consumption. Mobil 1 synthetic and filter went in today...

[dfather99]

The rental car company i work with uses firstone for their "lofr's" lube oil filter and rotations. and they don't mess with the rental vehicles but from talking to them perosanly i wouldn't take my car there. to put it softly they have "quota's" what ever the hell that means right

 

That is why i take it to either myslef or a known mechanic. The trick is to take it to a place that only does oil changes and doesn't wan't to touch the rest of the engine. cause they don't have anything to gain by messing with your rig. ie. jiffy lube(only if you watch them) and wal mart(same deal) places like monro, midas, firstones i dono.

[OR99.5Speed]

UPDATE:

 

I've put about 5,000 miles on the Pathfinder since then, a lot of it highway driving around 3700 RPM. I've taken it up to 110 MPH with no problems.

 

It's cold here in Indiana, and I have noticed that the truck leaves a cloud of blue smoke if I get on the throttle when the motor is dead cold, i.e. sitting overnight. I haven't noticed blue smoke or oil consumption at all when the engine is warm.

 

Also, the Pathfinder has not noticably been consuming oil. I don't add oil between changes. The dipstick is ridiculously hard to read but it shows full even after I repeatedly check it. (I learned my lesson before)

 

One thing is that the Pathfinder still runs a little rich. After a 600-mile road trip there will be a little bit of black soot over the rear bumper above the tailpipe. I can also see black smoke the rearview say, racing from stoplight to stoplight, seemingly over 4000 RPM.

 

Maybe the O2 sensors have been fouled? Gas mileage isn't too different than before, maybe 10 less miles on a tank but certainly within the window of error. No codes or anything.

 

Any clues?

[navygz19]

Man...it sounds like you drive the snot out of your pathy (it's not a Maxima you know ) Maybe you should consider being a teensie weensie more gentle w/ it, especially if yor burning oil and are considering the fact that you may have fried your piston rings

I've put about 5,000 miles on the Pathfinder since then, a lot of it highway driving around 3700 RPM. I've taken it up to 110 MPH with no problems

Pathys have no business traveling at 110 mph!!! Again, maybe c onsider being a little more careful.

I have thouroughly enjoyed reading these 3 pages of...ummm...literature!

[OR99.5Speed]

I put the 110 MPH part up there knowing I would be chastized for it...Higher speeds give you an excellent indication of what needs attention. By the way, these are on deserted highways, not passing traffic. PSI is set at 36 and I have good condition S-rated tires with no bubbling and perfect alignment.

 

I was getting an alignment a couple of weeks ago at Sears. The attendant asked me, "Do you feel any vibrations or pulling?". To that I responded with a smile, "Yeah, there's a vibration from the rear of the car about 96 MPH on up." He checked "No" and wen't to the car.

 

I constantly went 138 in my chipped VW GTI 1.8T, I needed aerodynamics. You could feel the float at over 130, and could also feel the suspension working at 100% soaking up irregularities that would have gone unnoticed.

 

I drive the Pathfinder pretty hard at times, but not all of the time. I'm not the guy weaving in and out of traffic on the highway and I don't drive like a jackass. I'm the one with the cruise set at 85 with the Valentine 1 on. :bow:

 

The piston rings aren't toast. I just thought they were when it was actually my MAF that was broken. I don't think anything is really. It seems just as slow as before, but there are no weird noises or knocks from the top or bottom end. Being a manual, I drive it admittedly more spirited than an automatic, but that is just around town.

[OR99.5Speed]

it's not a Maxima you know )

 

We just sold my brother's modded 2001 AE 5-speed Maxima. :sniff:

 

When I drove it I got worse mileage than the Pathfinder...also I always thought I was going to get a ticket, even with the V1. I'm not sure I can have a fast car...

[M in KC]

OR99, consider running the prescribed amount of Sea Foam in your crankcase. My '91 exhibited the same symptoms of oil consumption as you describe. 5 oz. of that stuff and my valve guide seals are tight again and i haven't had to add a drop of oil between changes since.

 

JMTC

M