Oil Consumption Mystery Solved!

[ZEUS]

Yeah, I think the title of this thread will end up being changed - or should be. I'm not convinced either. Def. worth a look though!

[blacksambo]

Where is Tone on this EGR issue? He always seems to speak common sense.

[Trudy Carp]

I was so excited to here that an Isuzu dealer actually knew how to properly deal with VX issues, I wasn't totally clear on how this happens, left out a detail.
The egr restriction causes the computer to slightly richen up the the fuel mixture. This washs out the rings and the oil becomes slightly deluted with fuel. This also contributes to pcv restriction within the lines. Denver Isuzu charges $208 to run a special chemical cleaner through the system to clear the tube and all the lines. The gas in the oil slowly damages the bearings. Since the computer made the adjustment, you may only see an intermitant check engine light in response.

[IndianaVX]

before my vx threw the belt, i was looking at different instrument "snakes" , and rifle cleaning brushes, just for the purpose we are talking about, cleaning that tube......if its the same one im thinking about, you can see the end of it in the throat of the trottle body. 7.62 seemed a little too tight, and i didnt go real deep at all. plus i think there is a bend or two in there, so thats why i was thinking about an trumpet or french horn snake. these snakes are like a tightly wound spring, thats kinda stiff, but will go thru tubing and corners and such, and they have a stiff NYLON brush on each end. the whole snake thing is about 3 feet long. feed thru the throttle body, come out at the egr? my idea was cut short, and still have the stuff, but not the vx to work on.
i had also been using sea foam deep creep spray down that tube, as it breaks up carbon making it easy to scrub away, but i dont know how well a nylon brush would hold up with the spray. if it would melt the plastic, also why i was looking at the rifle bore brushes.
sitting here thinking aobut this, i wonder, if after soaking the tube in deep creep, and letting it soak for a bit.....if the "right brush" could be tied to a light, yet strong string, then, feeding that string into the tube in the trottle body. attach a shop vac at the egr, suck the string thru the tube, and out the egr, shut off vac, and pull the brush up thru the tubing, and repeat. dont know, wish i could try that one out. sigh

well, ill quit rambiling, but i know that tube is always dirty on mine, and when i clean my egr, i always cleaned that tube best that i could,but i never felt like it was the best cleaning that could be done.............

[UtahVXer]

This link has been posted a few times before; maybe it should be referenced permanently somewhere, since it is a common persistent issue.
http://isuzufaq.ibctech.ca/#faq1

[Trudy Carp]

I must start by apologizing for the errors in the explanation for how the Egr tube started it all. This was originally spread out on 5 pieces of Post it notes and after many interuptions, it still took me half an afternoon to finish the post. I called Keith for a clarification.
Once a small amount of carbon starts building on the inside of this tube, the computer reads it's effect on flow and riches up the fuel. This washes out the rings and small amounts of raw gas begin to contaminate your oil, bearings don't like this. After a short while, combustion gases start getting past the rings placing more crankcase pressure on the pcv system, sucking gas diluted oil up into the intake to further add to the carbon buildup in the tube and confuse the computer. ( ever have an intermittant CEL that kept insisting the upstream oxy's were a problem?) It was not the egr tube that would be plugged on blown motors, it was the pcv valve and lines. The fuel contaminated/low oil conditions damaged the rings. Mine is scheduled for this service and I will share my results.

[etlsport]

quick way to check on whether or not this is happening to you would be getting your oil tested... http://www.blackstone-labs.com/

i had mine tested not too long ago... no abnormal traces of fuel found in my oil.. i burn about 1 qt every 3k

[Ldub]

I must start by apologizing for the errors in the explanation for how the Egr tube started it all. This was originally spread out on 5 pieces of Post it notes and after many interuptions, it still took me half an afternoon to finish the post. I called Keith for a clarification.
Once a small amount of carbon starts building on the inside of this tube, the computer reads it's effect on flow and riches up the fuel. This washes out the rings and small amounts of raw gas begin to contaminate your oil, bearings don't like this. After a short while, combustion gases start getting past the rings placing more crankcase pressure on the pcv system, sucking gas diluted oil up into the intake to further add to the carbon buildup in the tube and confuse the computer. ( ever have an intermittant CEL that kept insisting the upstream oxy's were a problem?) It was not the egr tube that would be plugged on blown motors, it was the pcv valve and lines. The fuel contaminated/low oil conditions damaged the rings. Mine is scheduled for this service and I will share my results.

What's the point of getting the EGR tube serviced if the rings are, as you say, damaged?

[Trudy Carp]

It has improved the way she runs, better smoother take off. Still plan a set of plugs this weekend. I can read my oil dipstick better. Oil was so diluted, the dipstick just looked wet top to bottom, couldn't establish a level. Now, after a week on this oil change, the oil is thicker and you can easily determine the level. Still doesn't smell of fuel, yet.

Bottom line, not all of us will be lucky enough to avoid a blown engine in spite of the egr service. I'm sure, in a lot of cases, it'll be "too little, too late". I fully expect mine to go bang. It was pretty bad, you could smell fuel on the dipstick 1000 miles after a fresh change. I'm thinking I already have the beginings of bearing damage and am debating getting the bearings replaced while I still have a good motor to do it to. Waiting till she blowns doesn't leave you much to work with.

Hope some of you had low enough miles to take advantage of this info and plan regular servicing of the egr system.

[blacksambo]

For whatever it's worth I queried my dealer about egr service and they stated unequivocally that there was no such thing. Yes, they advised leaving the whole thing alone and that in many years of Isuzu service they never have touched or replaced one. This seems funny versus all the wisdom expressing behavior to the contrary on this site, but so far both our '99's have never been touched in 100K miles???

[JHarris1385]

I can read my oil dipstick better. Oil was so diluted, the dipstick just looked wet top to bottom, couldn't establish a level. Now, after a week on this oil change, the oil is thicker and you can easily determine the level.

HUMMMMM..........maybe this is my problem
I have NEVER been able to determine the level of my oil and could not figure out why. The dipstick looks wet 3/4 of the way up the whole stick with thin oil residue. SH1t something else to fix on it.

[nfpgasmask]

That's really weird. Are you sure you are not overfilling? I change my oil every 3000 with Mobile-1 10W. After I change my oil, the oil is so clean it is hard to see on the dipstick, but you can certainly see a line going horizontally across the stick marking the level. After about 2000 or so miles, my oil begins to blacken, making the level very easy to detect. I have never noticed a gasoline smell on my dipstick. I will have to take a closer sniff next time I am under there.

My VX takes exactly one 5 quart jug of oil to fill her up. I burn oil pretty regularly as well. In between oil changes I probably will add at least a quart, maybe a quart and a half, depending on how hard I drive. I change my PCV almost every time I change my oil as well. I have no CELs and my VX runs good. I still worry however.

Bart

HUMMMMM..........maybe this is my problem
I have NEVER been able to determine the level of my oil and could not figure out why. The dipstick looks wet 3/4 of the way up the whole stick with thin oil residue. SH1t something else to fix on it.