High silicon (dust?) and iron in VW 2.0 TDI

[landyman]

UOA done on my Volkswagen Amarok 2.0 TDI. This is the fourth yearly analysis - always done before service. Things were ok for the previous three.
Now, however, things have gone horribly wrong in my opinion.

Diagnosis from wearcheck:
Cylinder/liner wear rates are high. Piston and ring wear rates are higher than normal. Check that blow-by is not excessive. No fuel dilution evident. Higher than normal silicon (dust) level in the oil - check air intake system for leaks and for defective oil filler cap, breather or dipstick and dipstick holder. Dust entry made the oil unfit for further use. Oil already changed do not drain again. Please return feedback.


Some background - about 2000km ago I saw smoke coming from engine compartment one morning, and found that the crankcase breather pipe was not properly clipped on to tappet cover. This can then suck in unfiltered air after the filter into the engine :-( Vehicle was at dealer shortly before that, but they said they did not work in that area.

Code


1 2 3 4

Miles in service: 7616 7400 8680 5740

Vehicle mileage: 27000 34300 43000 48800

Iron normalized

per 1000km (621 miles): 5ppm 5.5ppm 6ppm 29.5ppm


The question is - how much permanent damage will the dust have done, and will it get better with clean oil now?

 

[Bjornviken]

What oil are you using?

 

[landyman]

Originally Posted by Bjornviken
What oil are you using?


Dealer serviced; this is what they say: Castrol Edge Professional LongLife III 5w30

 

[CT8]

The dirt sands the cylinders etc What ever wear there is is permanent. Change the oil and drive the car. It is not worth worrying about.

 

[Cressida]

My guess is there was/is something going on beside that slight increase in dust that caused your wear numbers to bump.

 

[landyman]

Originally Posted by Cressida
My guess is there was/is something going on beside that slight increase in dust that caused your wear numbers to bump.

Let's hope it was, and not is. In fact, it got four new injectors last year courtesy of VW - starting with a bit of smoke. One injector was not properly installed and came "loose" while driving making a horrendous racket. Had to have it flatbedded back to dealer.

 

[landyman]

Originally Posted by CT8
The dirt sands the cylinders etc What ever wear there is is permanent. Change the oil and drive the car. It is not worth worrying about.

You think it will be fine as a once off occurrence? I realize the wear is permanent :-(

 

[CT8]

Originally Posted by landyman
Originally Posted by CT8
The dirt sands the cylinders etc What ever wear there is is permanent. Change the oil and drive the car. It is not worth worrying about.

You think it will be fine as a once off occurrence? I realize the wear is permanent :-(

It is not worth worrying about just drive it.

 

[landyman]

Why do used oil analysis if you can't worry

 

[Donald]

I would do another oil change just to make sure the iron and silicon are all gone. An oil change should get most. A 2nd oil change will get almost all of the rest.

So some dust got in and caused some wear. The cylinders are worn a little more than normal for the mileage.

But as other have said, no matter what the answer is, what are you going to do about it. Most likely nothing. Your not going to tear down the engine and rebuild it. Nor get a new engine or sell the car because of some extra wear.

So you live with it. Mistakes are made all the time with cars. It normally does not ruin them,

 

[dnewton3]

Not time to panic.
Time for patience and continued diligence.

It's likely that the uptick in Si would explain the cylinder wear; both the Fe and Cr indicate there's something afoot.

You have a few choices ....
- drive it for a few hundred miles (kms) and get another oil/filter change. Do this perhaps one or two times in short distances. This is an attempt to flush out the Si and excess metals. Also - work diligently to see if you can find the Si intrusion. Then, wait until your annual OCI and take a sample again. See if things have not come back down to a normal state.
- if you don't want to spend the money on a couple quick OCIs, that's OK, but realize that even if the event was a one-time thing, you're still going to see some residual evidence in the next couple UOAs, if you don't choose to flush the system in the aforementioned cycle flushes

Either way, I'd see if you can find an Si leak. If the Si and Fe and Cr are elevated AFTER a few flush cycles, then you have true contamination intrusion and it's an issue. If they subside, it's nothing to freak out about; you engine will survive this event and motor on.

 

[landyman]

@dnewton3 - thanks for the reassuring post

I am definitely planning on doing another change in say 2000km - perhaps do an oil analysis at the same time as well.

The silicon source is most likely the crankcase breathing pipe that was left off by a dealership :-( It is getting its annual service now so I've asked them to properly check all possible leaks.

(Sorry for posting in wrong section of forum :-o)