1997 1Z Oil Consumption < 200K miles

[markd89]

I'm running the 1Z engine from a 1997 Passat TDI in my conversion. Oil consumption is high at about 1 quart per edit:500 miles or so. The engine has < 200K miles and has been running Rotella T6 5-40. For now, I just add oil at each fillup but I'd like some ideas on causes/solutions.

Since the engine is not in a Passat anymore, I'll list the changes from stock and other factors that might be useful:

1. Home made PCV filter/catch can. PCV gasses run into a 1/2 gallon bottle to filter them before being returned to the intake as stock. Oil does collect in this but nowhere near the same amount as is being used.

2. Disabled EGR.

3. Malone tune appx 1.5. DLC1019 injectors. Air-water intercoolers.

4. Stock turbo. The outlet is wet with oil, but there is no big pool of oil in the intercooler.

5. Highway 10 psi boost typical. Max for the tune is 16 psi.

6. Highway RPMs are 3000-3300 typically, which is more than a Passat would do in 5th gear unless you were going really fast.

7. For most of the 50K miles on the swap I have been running an additive of 2 stroke oil + Power Service. I recently switched to just Power Service because I was thinking maybe the 2 stroke oil residue was perhaps affecting the rings. After doing this, I see no change in oil consumption but the oil seems to be a little clearer.

8. Hot oil pressure

1000 rpm (this is my idle speed) appx 12-15 psi
2000 rpm 30 psi
2500 rpm 40 psi
3000 rpm 50 psi

So my questions:

What is typical to cause oil consumption in a 200K mile 1Z?

Any clues on my consumption based on the data above?

If I want to put off a repair, would using a heavier oil, i.e. 10w-50 slow consumption? Recommendations?

Thanks much!

Mark

 

[Yblocker]

You will get a big range of "average" on this question. It ranges from a group that inserts a face if the engine burns a quart every 5,000 miles which is completely normal, to the other end of the spectrum where feeding a quart every 1,500 miles is felt to be par for the course. Feelings aside, your consumption is high enough to create visible, blue oil smoke, and is not likely to be improved much with a heavier oil, though you could try a 15W-40 Rotella or equivalent and not hurt a thing at this point.

It sounds to me like the turbo is likely worn, and combined with worn valve guides, your oil consumption isn't surprising. At 200k, and 20 years, the valve guides will be worn, and contrary to what some will tell you, worn valve guides will cause increased oil consumption on a diesel too. If it were me, I'd check for play in the turbo shaft first. A bit of detectable side to side play is normal but any axial play (in and out) is sign of wear and will cause oil burning.

 

[vtpsd]

A quart per 500 is pretty high, easy check would be the turbo. I dont think valve guides can make it burn that much. Are you leaking? That stupid plasic breather tube on the block can loose a lot of oil.

I have a good k03 turbo from an AHU that would bolt on that I would sell for $100 if you wanted to go that route.

 

[UhOh]

A lack of pooling doesn't mean the turbo isn't passing oil; just means that you're supplying enough boost to push the oil through.

From my understanding of oil consumption issues, ranking from the most likely to the less likely, these are the more common sources:

1) General leaking (numerous places);
2) Turbo;
3) Rings;
4) Cylinders (rings might be OK, but they cylinders are oval'd out);
5) Valve seals.

#4 & #5 could be swapped around as they're likely close in commonality.

 

[mohawk69]

I changed the gaskets on the oil cooler and I changed what I think is called the J tube. I was marking my spot wherever I parked so have you checked for actual leaks?

 

[Yblocker]

A leak to contribute meaningfully to loosing a quart per 500 miles would be substantial and obvious, which makes that diagnosis easy enough. Glazed cylinder walls will do it and fits in the above list around number 3. That can be improved with the engine still in the vehicle, but at that point you need to be measuring the bores for taper and wear and becomes a bigger job. Start with the turbo.

 

[markd89]

Gents, thanks for all the help!

There are no meaningful leaks. I did spot a little oil on the turbo oil return where it connects to the block. The bottom of the turbo will be damp with oil. I'm not sure where that is coming from.

I don't have clouds of smoke. Usually I don't see any in the mirror, but I'm not behind either. I'll ask a friend to tail me and maybe record it.

But, first, I'll pop the intake off the turbo and give it a wiggle since that sounds like a good possibility.

I'll report back with what I find.

Thanks again!
Mark

 

[Owain@malonetuning]

An older VW diesel that doesn't leak oil

Agree with the turbo, best to start with the easy stuff first. Does it smoke blue on cold startups? under heavy load? or is consumption pretty steady?

 

[markd89]

An older VW diesel that doesn't leak oil

Agree with the turbo, best to start with the easy stuff first. Does it smoke blue on cold startups? under heavy load? or is consumption pretty steady?

No big oil leaks because I already replaced the rear main seal, oil cooler, oil pan gasket, PCV tubes, valve cover gasket, turbo oil feed line, etc. ;-)

I only see smoke on very heavy acceleration. I figured it was fuel not oil. I'll take a closer look. I'll also have someone do a cold start while I watch.

Thanks,
Mark

 

[BobnOH]

Time for a compression test?

 

[UhOh]

Bob, there was a recent discussion in which one of the BIG guns around here noted that oval'd cylinders won't show up in a compression test (yet such can account for oil consumption). If one has a compression tester it wouldn't hurt to run a couple of tests, though they could end up being inconclusive vis a vis this issue.

 

[AndyBees]

Mark noted the engine is in a vehicle that he did a swap (78 VW Bus). So, like me with my Vanagon engine swap, he went over that engine with a fine toothed comb to make sure it didn't have oil leaks. At 200k miles on the engine (originally belonged to TDI Club member MrGutWrench), my engine has no oil leaks..... a damp spot here and there! But, no leaks. (My 2000 Jetta with 361k miles has no leaks.)

Mark, as a few others have suggested, I think the oil loss is through the Turbo.

I'm surprised at your boost numbers with a Malone 1.5 Tune. Those are the numbers on my ALH prior to a Malone Stage 1 tune. Mine spikes (and that may be a problem) up to 24 psi and runs a steady 15 psi on level grade at 70 mph...... cranking the same RPMs you mentioned.

Start with your Turbo!

 

[markd89]

Andy, thanks as always!

Turbo is starting to make sense. The outlet is always wet. The outlet tube is not a perfect fit. I think it's 1.25" and the outlet is 1.1" or something. Even with it clamped down, I get some oil leaking out there. Seems that I would need a fair amount of oil getting lost to see that. Today I'll pull the inlet and feel the wheel.

On boost.. Hard to remember but I think it did used to boost higher, maybe 18 or 19. That also supports the turbo being tired.

Thanks again and I will report back!

 

[AndyBees]

Yeah, I'm a bit concerned about my VNT15 Turbo. It seems to be putting far more oil through it than early-on~! Seems it took a midge over 1 quart of oil to keep it topped off during the almost 12k mile road trip last summer, compared to less than a half qt on the same trip in 2014. And, like yours, I'm seeing oil at the hose clamp coming off the Turbo.

 

[markd89]

I took off the intake and wiggled the wheel. There is some play there - not enough to touch the wheel to the housing but enough to leave maybe a sheet of paper width gap.

I took some videos which show:

1. I have not been as fastidious as Andy I did replace everything leaking and questionable but didn't do a full rebuild. It could be a lot cleaner in there.

2. You may be able to see the wiggle.

Please take a look and see what you think. I am not opposed to replacing the turbo anyway as 200K miles is a lot and I'm not seeing full boost.

http://realityisreality.com/turbo/turbo1.mp4
http://realityisreality.com/turbo/turbo2.mp4
http://realityisreality.com/turbo/turbo3.mp4

 

[UhOh]

I'm a bit bandwidth challenged right now so I am not able to watch those videos. But...

There's radial play (which I am assuming is what you saw when you said "wiggle"), and then there's axial play. There will always be some radial play because there's no oil pressure (assuming you're not reaching in there with things running! ); not touching the housing is good. Axial play is the thing that's the greater concern- shouldn't have any: pulling in/out on the shaft is how it's checked. More knowledgeable folks can state how axial play influences oil passing/consumption- my memory banks don't contain any relevant info on this (but I could guess that it has a lot to do with it)

 

[markd89]

I'm a bit bandwidth challenged right now so I am not able to watch those videos. But...

There's radial play (which I am assuming is what you saw when you said "wiggle"), and then there's axial play. There will always be some radial play because there's no oil pressure (assuming you're not reaching in there with things running! ); not touching the housing is good. Axial play is the thing that's the greater concern- shouldn't have any: pulling in/out on the shaft is how it's checked. More knowledgeable folks can state how axial play influences oil passing/consumption- my memory banks don't contain any relevant info on this (but I could guess that it has a lot to do with it)

Yep, radial play is there. I didn't notice any push/pull on the shaft.

 

[markd89]

I have a video of a cold start and a little revving: http://realityisreality.com/turbo/cold-start-and-rev.mp4

Any clues there?

I had a friend follow me and video and there is smoke only on heavy throttle and it looks black. I'm figuring that's fueling not oil.

Any ideas?

Thanks!
Mark