Gas in the oil? I think we may be onto something here

[MrJim]

Many of you know that I have been battling very weird oil issues for just over a year now. It all seemed to focus around an oil change on my Pathfinder last Winter where they used an engine flush that "seemed to be forever stuck in the motor throughout multiple oil changes. Even then, it would quickly break down my oil too.

 

It was so odd. I could putter around town, or on the trails for hours and days, but if I hit higher RPMS, like jumping on the freeway, my oil would quickly thin and start blowing past the rings until there was no oil. It even seemed to smell like that engine oil flush every time we spelled it. I have to say that this may finally repair this unending nightmare that I have fighting all year long.

 

So my oil issue was not my pressure sending unit as i thought. The more I read about it and think about it, the more I think that my friend Rob is right with the whole fuel injector idea. I was reading several accounts of bad O rings on the injectors causing gas in the oil, causing it to smell like mine and in turn breaking the oil down quickly and the leaks happen faster as the RPMs are higher and the fuel pressure increases. I have to say that was pretty damned ingenious of him to to put all of that together. I have been watching videos on how to remove and service the injectors tonight and except for removing the intake to access the driver side injectors, it doesn't look that hard. I was even thinking about looking into 300z rails and injectors, because apparently they have a much higher flow rate and that was one of the main reasons that the same engine as the Pathfinder has more HP in the 300z cars. I am really excited about maybe finally winning this battle. I am sorry for not hearing this more openly when Rob brought it up before. I think he really has this pegged and now I just need to do the work to find out. Either way, new injectors couldn't hurt. just like on my truck, if you have gas smell in your engine, and it appears to be breaking down the oil consistency as soon as you rev higher and start to build higher pressure. This could all come down to bad O-rings no longer sealing the injector properly. OH, there will be a video, especially if this fixed my issue. Making a "how to" removed, refurbish, and reinstall your Pathfinder O-Rings would be a good one to have out there anyway. I have high hopes that this could finally be the answer to this crazy problem with my oil.

 

I can't tell you how excited I am to think that six small injectors or even just their O rings could be causing all this.

 

Be sure to stay tuned as I am hunting for injectors and injector kits.

 

We will see shortly......

[silverton]

Good luck!

[MY1PATH]

if you do go to 300zx injectors and rails for your vg32(?) get the top-feed ones as they are easier to deal with, easier to find and easier to upgrade in the future...

[nismothunder]

Lets hope this fixes it because my engine is doing something very close to what yours is.

[sewebster]

How does the gas get into the oil from the injectors?

[nunya]

How does the gas get into the oil from the injectors?

leaking past the injector when the cylinder ain't firing and dumping the fuel right in the oil pan... went through it with my 4runner one of the times i had the top end apart, didnt have one of the injectors seated 100% correctly and it thinned to oil out in no time (40 weight oil too).

[sewebster]

leaking past the injector when the cylinder ain't firing and dumping the fuel right in the oil pan... went through it with my 4runner one of the times i had the top end apart, didnt have one of the injectors seated 100% correctly and it thinned to oil out in no time (40 weight oil too).

 

You mean leaking past the rings? But won't it be stopped by the closed intake valve (I guess it could be leaking).

[lint]

How many miles on your rigs Nismothunder and Mr. Jim?

[MrJim]

I have 185,000 miles on the odometer.

[Precise1]

I was even thinking about looking into 300z rails and injectors, because apparently they have a much higher flow rate and that was one of the main reasons that the same engine as the Pathfinder has more HP in the 300z cars.

 

I'm pretty sure the HP comes from different heads, cams, etc and the flow rate is just there to keep up, not the other way around.

 

In all honesty, before you start chasing theories and buying parts, why don't you do (or have performed) compression tests (both dry and wet) and maybe test the fuel pressure/leak down rate, etc to get some solid info first.

 

Can the injector seals be damaged/shrunken from the vehicle sitting so long??

 

B

[Cuong Nguyen]

I too and in the hunt for answers. Perhaps find out a way to test the fuel pressure and see if it drops after you prime the fuel pump. Pull the injector rail out and set a piece a wood under it and see if the injectors leak after you prime the fuel pump. I don't think I've heard of the o rings shrinking or going bad but I may have that issue seeing that I have like over 210k miles on my motor.

[MrJim]

I'm pretty sure the HP comes from different heads, cams, etc and the flow rate is just there to keep up, not the other way around.

 

In all honesty, before you start chasing theories and buying parts, why don't you do (or have performed) compression tests (both dry and wet) and maybe test the fuel pressure/leak down rate, etc to get some solid info first.

 

Can the injector seals be damaged/shrunken from the vehicle sitting so long??

 

B

 

 

I think that it has to be an issue with damaged or shrunken injector o-rings. Your right about having pressure tests done. I need to do that. I see that Walmart offers a fuel injector cleaning for $18. If I have bad o-rings, that won't do anything for me, but I wonder what they do exactly (because its just Walmart and only $18)? I have seen reputable shops with large machines that they hook to the fuel rails and it washes them out methodically, but Walmart may just put something in your fuel tank? I am curious to find out.

[MrJim]

I too and in the hunt for answers. Perhaps find out a way to test the fuel pressure and see if it drops after you prime the fuel pump. Pull the injector rail out and set a piece a wood under it and see if the injectors leak after you prime the fuel pump. I don't think I've heard of the o rings shrinking or going bad but I may have that issue seeing that I have like over 210k miles on my motor.

 

They sell o-ring replacement kits for a reason. They must go bad from time to time. Its a first for me, but I have not seen it all. Yet.

[5523Pathfinder]

Jim, I would do what was suggested by testing the fuel pressure. T in a guage and pinch of the return line. If the pressure drops, then you have a leak. Heck, you can pinch of the rubber hose connecting the rails to isolate which side has the issue. Plus, if you were leaking that mcuh fuel, you should either be running rough, or pissing through a lot of gas. You could go as far as to have the emissions checked. That would tell you if you are not buring correctly. Also, not buring all the fuel off could be from many other factors(plugs, wires, compression, ect). One more thing may be carbon buildup on the valves and piston. Our engines are well know for it and preforming a decarbon service might help as well. This would be done through the intake or a vacuum line. You could use a bit of water and do it yourself.

[MrJim]

Jim, I would do what was suggested by testing the fuel pressure. T in a guage and pinch of the return line. If the pressure drops, then you have a leak. Heck, you can pinch of the rubber hose connecting the rails to isolate which side has the issue. Plus, if you were leaking that mcuh fuel, you should either be running rough, or pissing through a lot of gas. You could go as far as to have the emissions checked. That would tell you if you are not buring correctly. Also, not buring all the fuel off could be from many other factors(plugs, wires, compression, ect). One more thing may be carbon buildup on the valves and piston. Our engines are well know for it and preforming a decarbon service might help as well. This would be done through the intake or a vacuum line. You could use a bit of water and do it yourself.

 

 

 

Thanks. I will try that. I am going through ALLOT of fuel lately and it is "sometimes" misfiring. I have new plugs and wires in it, plus new PCV valve. I am not sure about my emissions, because I think we took out the Cat when I added the dual exhaust. I have to check. Its been a few years. Tell me more about using water to do a decarbon service?

[5523Pathfinder]

Decarbon by water? Well, whay you would do is get a cup or container to hold about a cup or more(pop can amount, 12oz is perfect). Find a vacuum port after the throttle body. Some use the brake booster hose, some use smaller. If you use the booster hose, pinch it off after you disconnect it from the booster so the engine wont die(its a huge vacuum leak). While the engine is running, put open end in the water then pull out. You only want to pull in a small amount at one time. If you pull too much in, you risk the chance of hydrolock!! You will fee the engine stumble then clear up. Its a good idea to hold the throttle open a bit to raise the idle. Repeat until the container is empty. Once again, do not rush it! Once you are done, go driv eyour rig, kinda hard to burn off anything left behind. Oh, it may smoke some. Thats ok. Just drive around until the smoke stops. You are done.

 

If you were closer, I would hook up our intake apperatice to your rig. It basicly does the same thing, except the nozzle atomizes the chemical and is sucked through the throttle body and entire induction system. This works well also. I do it every 15k or so.

[Precise1]

Derek, I have heard of people using a spray bottle on mist and spraying directly into the intake tube. Is there any reason not to use that method? It seems a little more user friendly and easier to meter.

 

B

[5523Pathfinder]

Ive never heard of someone doing it that way! It might work, but Im not sure it will have the same immediate affect. When using a chemical, the atomization allows it to soak into the carbon, then it basicly rips is off, or melts. You can try misting the water, I dont really know. I have seen guys do it the other way time and time again. Even did it myself a few times.

 

Forgot to add that going through the intake boot, is creating a huge air leak. Keeping the motor running, opening the tube and spraying the water, would be a heck of a juggling act. You can control the leak by using a vacuum line. Easy to pinch or plug.

Edited December 2, 2010 by 5523Pathfinder

[lint]

I've used a mister before in decarbonizing my other cars....just haven't gotten around to doing in yet on the 'finder. Basically, I just take out the air filter, rev the motor and mist.

Like others say....be very careful not to use too much water, as you may hydro-lock! And that would be bad...

[Precise1]

When using a chemical, the atomization allows it to soak into the carbon, then it basicly rips is off, or melts. You can try misting the water, I dont really know. I have seen guys do it the other way time and time again. Even did it myself a few times.

Well, misting VS vacuum line, misting seems like it will disburse better. After all, the vacuum line is not sucking it up and distributing it drop per drop to every cylinder. I don't know...

 

I'll experiment after my overdue smog check...

 

 

Basically, I just take out the air filter, rev the motor and mist.

Exactly what I had had thought.

 

B

[XSrcing]

Faulty injector 0-rings WILL NOT introduce fuel in to your oil. You will either have a vacuum leak or fuel will leak on to your intake manifold. There is NO path between the injectors to the oil pan other than through your piston rings.

 

Do a compression test and I bet you will find one or two cylinders very low with ring blow-by.

[krmiller07]

I just solved this 'rough running, gas sucking' problem, a couple of months ago. After talking to several 'techs', who all said I had everything from bent valves to a vacuum leak (intake gasket) because it seemed to run better after it warmed up). I decided to try an 'intake cleaning'. Rather than try the misting procedure, which I have done before ( I recommend the BG Products). I decided to try using a product made by Chevron. There are 2 types available. Since I've used 'TECH-RON', which is made by them, in the past with great results. I used 2 bottles to about a 1/4-1/8th a tank off fuel. Initially, the truck will run like crap. But bear with it. As the fuel level gets lower, it's running a higher concentration of cleaner through the system. Let it do the work, many times the carbon build up, is heavy and hard. Caked to the valves, intake runners etc. Once it softens up it will burn off. Now when your nearly running on empty, fill up the tank and drive the thing hard. Making a point to keep the revs up, and the air/fuel mixture rushing through the system. After a couple of days, you should notice an improvement in idle, mileage and overall performance. I read a TSB on here, that addressed this problem quite a while ago. However they were recommending that as a fix, the techs were suppose to remove the heads and remove the carbon with walnut media blasting.

Edited December 4, 2010 by krmiller07

[ripadam16]

I just solved this 'rough running, gas sucking' problem, a couple of months ago. After talking to several 'techs', who all said I had everything from bent valves to a vacuum leak (intake gasket) because it seemed to run better after it warmed up). I decided to try an 'intake cleaning'. Rather than try the misting procedure, which I have done before ( I recommend the BG Products). I decided to try using a product made by Chevron. There are 2 types available. Since I've used 'TECH-RON', which is made by them, in the past with great results. I used 2 bottles to about a 1/4-1/8th a tank off fuel. Initially, the truck will run like crap. But bear with it. As the fuel level gets lower, it's running a higher concentration of cleaner through the system. Let it do the work, many times the carbon build up, is heavy and hard. Caked to the valves, intake runners etc. Once it softens up it will burn off. Now when your nearly running on empty, fill up the tank and drive the thing hard. Making a point to keep the revs up, and the air/fuel mixture rushing through the system. After a couple of days, you should notice an improvement in idle, mileage and overall performance. I read a TSB on here, that addressed this problem quite a while ago. However they were recommending that as a fix, the techs were suppose to remove the heads and remove the carbon with walnut media blasting.

 

Mine's been getting bad mileage as well, I'd like to try this & see how it will do. Like to try the cheap stuff first & see if it works before digging higher. Do you remember how many ounces were in each bottle? Advance around the corner has a 12oz & a 20oz bottle. Don't want to under/over do it. Once you fill your tank back, do you drive it hard until that tank is empty or just until the improvement starts to show? Thanks!

[Towncivilian]

It doesn't matter which bottle you use, you can't overdose on Techron (PEA) in sane amounts (i.e. don't put three gallons of the stuff in your tank).

 

It is best to do short trips to allow the cleaner to soak in, don't burn through the entire tank as you would on a lengthy highway trip for example.

[ripadam16]

It doesn't matter which bottle you use, you can't overdose on Techron (PEA) in sane amounts (i.e. don't put three gallons of the stuff in your tank).

 

It is best to do short trips to allow the cleaner to soak in, don't burn through the entire tank as you would on a lengthy highway trip for example.

 

 

Ok I may be a little confused.

 

It sounds like krmiller07 is instructing to put a couple bottles in the tank when you only have about 1/4 tank of gas left, then run it to almost empty, & then fill up with regular gas (no Techron) & run that through

 

And it sounds like you (Towncivilian) are instructing to add a couple bottles into a full tank & just run that through on short trips until almost empty.

 

Sorry to sound like a complete fool, I just want to make sure I am understanding correctly. If I did mess that up, just let me know. Thanks guys.