High oil consumption/good compression ???

[sdeck]

So I have been burning 1Q motor oil every 800 miles or so over the past 7000 miles. This is more than double the rate before I cleaned the intake manifold, ports, and valve stems. Cleaning ports and intake valves solved my power and smoke issues, but greatly increased my oil consumption. My compression is 490/495/490/495. I was close to the same before the cleaning, around 470/480/500/490. I am wondering if my 40K+ on WVO caused the rings to stick. Past 7K has been strictly dino (at >$4.00 gallon).

Can I have great compression and still have bad rings?

Thanks,

 

[wjdell]

valve seals - leaks - WVO - do some UOA's.

 

[naturist]

If you cleaned the valves and valve stems, it is possible you damaged the oil seals on the valves. This would give the symptoms you describe.

 

[dieseldorf]

Can I have great compression and still have bad rings?

S, as somebody else suggested, the rings may be hung up and the piston bowls "filled" with unburned residue giving false high compression readings.

How 'bout that cylinder leak down test

 

[BioDiesel]

I thought I've read other posts here stating valve seal leakage wouldn'
lead to oil leaking past the valve stems. Because a diesel doesn't operate with an intake under vacumn as a gasser does. [My '64 plymouth succumbed to this. Coasting a long exit ramp would suck in enough oil to foul a spark plug.]

sdeck, if youre intersted, I did once read of a M-B owner who thought cold sarting on wvo had gummed his rings, and he de-gummed them with an oil additive. PM and I can try to relocate

 

[sdeck]

What I can't get my mind wrapped around is why the consumption more than doubled after scraping the valve stems and ports.
1. damaged seals (or removed the coke that was helping to seal). Lots of gurus swear it can't cause oil use with the turbo functional. Bentley's indicates it is a problem.
2. increased airflow creating more suction thru CCV. Been trying to find out if there is any pressure modulation or flow restriction in the CCV but haven't gotten a straight answer from anyone. Mine seems to be a hollow, completely unrestricted disk o' plastic.

Anyone ever try CC additives to remove WVO gumming?

Thanks for all.

 

[sdeck]

UOAs

valve seals - leaks - WVO - do some UOA's.

My UOAs are posted in the TDI UOA thread a while back. Haven't posted the latest since the car was having so much trouble with clogged intake, I figured they were a mess anyway. Previous ones showed WVO in the CC as evidenced by increased viscosity and high Na/K. changing my purging habits started bringing that down. I am due for an OC soon and will send a sample in.

 

[wjdell]

takes to long to search for that - post a link - or enter them in the TDI UOA database

link in signature

 

[DPM]

Any clues in smoke? I'd agree with the stuck/ clogged oil-control ring scenario and add that the same could apply to the turbo's seal rings.
Valvestem oilseals could indeed leak, especially noticeable on overrun directly following a cold start ( trailing throttle down a hill when cold) although the lack of boost at idle could make it obvious then, too.

 

[sdeck]

Smoke seems black or dark grey (not blue) and only apparent under pretty serious acceleration. I had attributed it to the P520s I installed right before cleaning the ports (it's an auto). No blue smoke except a little bit on started (couple puffs then gone).

There was a ton of coke built up on the valve stems. I had attributed it to WVO in the CC vapors condensing on the stems, but since my rear main seal failed, I have wonderd about deterioration of other seals, including valve stems. If they were shot, the draining onto the stems could cause the coking. Most gurus around here claim it is impossible for oil loss to be thru the valve seals on the TDI. Bentley's claims it is a problem during idle. I idle a fair amount sitting in traffic.

So I can understand poor oil sealing rings causing oil loss, even with 490 compression, but why did the consumption more than double directly after cleaning the intake?

 

[wjdell]

Because 2+2 = 4, and you said heavy accelleration - the valve seals were bad and you finished them off. You nay have several things going but new seals should be on the list.

Maybe AutoRX will help you - some say it works. Write AndyH he has had epxerience with ring problems maybe he can give you some ideas of possible fixes. They may not be to bad. If they are is dissassemble.

 

[sdeck]

Yeah, valve seals were the only things that made sense to me (especially since I removed the carbon plug that was helping seal them), but all the gurus say no due to turbo pressure............

 

[wjdell]

122 k is awful short life - I use no bio or waste fuels. VW discourages this for a reason. Maybe the oil got polluted early and helped, I think when you use BIO and waste oil life can drop to 3k. Never the less was it worth it. I depend on my car and would do nothing that would reduce its reliability. You know the seals are bad and maybe other things. It might be wise to tear down now and rebuild while all the parts are still good. Look at the mains replace the rings and seals. Make sure your turbo is ok, replace any needed parts. Find a good engine man if you can not do this yourself. Go back to ULSD or B5 max.
Good Luck

 

[sdeck]

oil consumption cause/resolution

So my Jetta failed emissions and I had to finally bite the bullet and get it looked at. I know the high oil consumption was either turbo, rings, or valve stem seals. Turns out it was probably all three.

Took it to Anuthee on Tuesday after deciding the head needed to come off regardless. Some gunk in head, cam was marginal (some spidering on ends of lobes), lifters were a mess; 5/8 had stopped turning in bore at some point. oil passages looked OK, probably due to AutoRX treatment. Pulled head off. Cylinders 2 and 4 were scuffed/scored on one side. underside of head wasn't too bad. Some injector streaming apparent on piston crowns. Heavier than usual ridge on tops of cylinders. Pulled #4 piston. coking evident on side skirt and rings. oil control ring spring was very stiff. rod bearing was worn. Looked at turbo. >1 mm side-to-side play in shaft.

I am firmly convinced this is all due to 42K on WVO. principle causes (aside from just running WVO) were failure to reduce OCI, too short of purges, and short shut downs on WVO.

Head is being rebuilt, new cam/lifters/valves, cylinders will be honed, pistons cleaned/re-ringed, will upgrade the turbo to a new VNT17.

here are the pics:

I will post a link to this on the alt fuels forum as well as the GC forum. I saved a bunch of $ when diesel was $5/gallon, but I am giving it all back now. I will not say definititively that WVO cannot be done in a TDI. there are examples of folks more anal and informed than myself doing it successfully for 100K+ miles. But I will say that very few folks are going to get away with this long term and it requires a lot of effort. I went into this with my eyes open and was proven wrong. Hope others can learn from this.

Oh yeah, this is what the engine looked like 40K after quitting WVO.

 

[hvacr9e]

hey the piston markings read backwards says wvo....wow amazing stuff

 

[Dimitri16V]

that lifter on the left was definitely not turning in the bore

 

[Franko6]

Steve,

You remember our conversation way back when... somebody was recommending some 'instant engine rebuild' in a can... yeah right. I told you then, it was rings.

The damage to the cylinders in line with the wrist pin is typical. It is all the clinkers falling through the valves and tearing things up.

The reason you have such great compression and lousey rings is what I have called pyrolysed WVO. If you recall Duluth Roosters engine, there were virtually NO rings. They were all stuck in the piston groove. The only reason D.R.'s engine was running was from the goo left over from WVO.

If you notice, the rings are not holding back the WVO in the combustion chamber. The brown crap on the pistons is what has gotten by the rings. That is the worst part of WVO damage, as it will then destroy the quality of the oil by homogenizing. Remember the old Mobile 1 ads? They'd take regular motor oil and Mobile 1 and put the oils in a frying pan. The regular oil would look like tar when the got done cooking it. That homogenized WVO will cook onto everything, especially the turbo and rings.. the hottest spots.

It doesn't do any good to do specto-analysis, as the WVO has the same spikes in the analysis as engine oil. Strange but true. The only portion of an oil test that is accurate to determine WVO homogenization of the oil is viscosity testing.

I wish I could find the article now, but the Argentinian Bus Service, a fleet of 30,000 buses, uses a blotter test developed by the service manager of the bus fleet. The buses use a good portion of their fuel derived from canola oil. The company was doing oil analysis, but by the time the reports came back, the bus might have gone another 2,000km. By the time they received the report, it only confirmed there was an impending problem. The bus company developed the blotter system as a 'quick check'. The first year, they cut the maintenance bill by an impressive amount

Look up 'oil blotter test'. There are several sites that have sprung off the findings from the Argentine Bus company.

The first thing I would do, if I had to be running WVO, is eliminate the EGR and I would also use the 'elephant nose' snorkel on the CCV. That would help.

The other thing I would do is ONLY run the WVO at highway speeds, do anally complete purges, make sure my nozzles were in tip top shape and go UNDERSIZE nozzles with an 11mm pump.

I think overfueling to make up for loss of power due to the viscosity of WVO fuel is a big mistake.

 

[VeeDubTDI]

I think overfueling to make up for loss of power due to heavy fuel is a big mistake.

Bingo!

 

[sdeck]

hey the piston markings read backwards says wvo....wow amazing stuff

ROFLMAO. That is damn funny. Almost worth the rebuild. not.

 

[sdeck]

Righto Franko. The rings (at least in piston #4) had coke built up mainly along one side. They were freely moving in the grooves, but the spring in the oil control ring was all "cokey".

Any suggestions for aNut to clean them up?

 

[AndyBees]

In case I missed it, what brand and weight oil were you using in this engine? Also, how often did you change it?

Lastly, was the IP performing ok?

 

[sdeck]

Rotella T 5W40 synthetic. When Ifirst converted it, I changed it at 8K twice, then bad UOAs made me go every 4K.

IP is good. No issues there.

 

[aNUT]

Ahhh...that's starting to look better.

 

[TomB]

Steve,

... The first thing I would do, if I had to be running WVO, is eliminate the EGR ....

Removing emission controls is another reason I would never run WVO.

If you have to break the law to make it work and add more NOx to the air WE all breath then it should not be done.

I don't see how anyone justifies their right to be cheap and run WVO with subjecting everyone else to harm from the extra pollution. Seems really selfish and self-centered and short-sighted.

To top it off this stuff is shown to kill engines!

 

[VeeDubTDI]

Because most of the folks who run WVO claim that it's actually cleaner with a zero carbon footprint. This absolves them of any responsibility to the Earth.

 

[vwcampin]

I fully expect to see all of you in the Performance section berating them for modifying their vehicles from stock. It should keep you busy

The thing about WVO is that it is illegal to begin with. It is not an EPA approved fuel, so I am a law breaker without touching anything on my engine.

While I agree that tampering with emission devices is not a good thing, you are wrong in indicating that WVO has "extra pollution". WVO is using a recylced product for fuel that has only recently been created, where diesel is a fossil fuel. The emissions on WVO are also much less. I believe you can successfully run on WVO without tampering with your emission controls.

http://green.autoblog.com/2007/01/30...e-oil-emissio/

The above test was done at an EPA Certified Lab and shows that NOX actually tested lower than diesel.

Another study:
http://www.buffalobiodiesel.org/svo_emissions.pdf

*Disclaimer* I have lowered my EGR via VagCom, I have not removed it like a lot of people on this forum to hopefully lessen the clogging of my intake.

 

[reynolcj]

As a newb to the forum (not diesel) can you share the cost associated with rebuilding the motor so as to discourage my desire for a WVO system? I messed around with it on my 85 jetta diesel, but have my reservations (just confirmed) about doing it with the tdi. Knowing the monetary damage would probably seal the deal for me lol. Feel bad for you but hopefully others learn from your documented mishap.

 

[sdeck]

Car is back from Anuthee. Big thanks to him for taking this on and sticking with it. Head rebuild (cam, lifters, guides, etc.), rings/hone, VNT-17. After 300 miles, much quieter, 90% reduction in smoke, no noticable oil consumption. Drives great.

 

[scubagli]

At least your honest, in saying that it can be done right. I will not run this tdi on wvo, If I had a stock one and commuted 100+ miles a day I would consider it.

 

[Pcar993]

hey the piston markings read backwards says wvo....wow amazing stuff

hahahA good catch!