Zeca

Ok I have been reading about the dreaded sludge problems on the 1.8T for a while. I have a '01 1.8T STD Quattro Avant and have been the only owner..Car has now about 135K with oil changes averaging 10K between changes. ALWAYS used Mobil 1 Synth oil...Am I free from this (potential)problem or could it still loom ahead??
What are the causes of it?
I am planning on keeping it for many years to come.

Opinions Please.

turbo510

My unfounded opinion is that sludge is more likely on the 1.8T because the oil line supplying the turbo is located in exactly the hottest place, over the exhaust manifold, turbo and cat. If you add short trips where the oil doesn't' get to normal temperature during the drive, and clogged or broken crankcase vent parts, the conditions are all there. When you shut off the engine, oil in the turbo line gets extremely hot and more likely to "coke", while the majority of oil in the crankcase has water vapor from combustion churned into it that doesn't get evaporated off.

Reggie

10K oil changes is too long IMHO. 5K or 6 months should be your change interval. Especially with a turbo. I would put a can of oil detergent in now about 100 miles before your next oil change.

ezveedub

I would agree with running 5K service oil changes also. Make sure you also use the larger oil filter also.

rohit13

Put some zmax in with the oil. It is used at the Audi dealers so I would says its safe to use. Or sea foam. And change the oil before 6k with 0w-40 If your going to use mobile 1. Any Audi approved oil will do.

Zeca

I'll try the CD2 stuff before the next oil change..

The main question I guess was if Synth. Oil (like the Mobil 1) was immune to sludge forming.

As I understood it, synth. oil is/was less likely to "cook off" which I thought was the main reason for sludging on our turbo engines...

Thank you all.

tom_20m

you could save yourself some money and try pouring some ATF fluid into your crankcase. You just need about half a quart. Make sure to drain out a bit of oil. Run it for about 100 miles before your oil change. The ATF has plenty of detergents in it and will also lubricate. I did the seafoam in my audi when I first got it and chunks of stuff came out the oil pan. Knock on wood.. no trans problems yet.

tom_20m

Almost forgot, I use to be a big fan of mobil 1 but have changed over to castrol. I put mobil 1 synthetic in my new toyota tundra 5.7L and it turned dark brown as opposed to staying a nice golden brown like castro did. Price wise they were both the same per quart and truck takes 7.5 quarts. The castrol seemed to stay cleaner when it was drained.

ezveedub

FYI, any oil that stays cleaner or looks like new longer than another oil, is actually not cleaning the engine. Oil that turns dark quicker is cleaning and removing build up from the engine, which means its doing it's job.

tom_20m

Hi Ezveedub, I know. Engine oil color is no indication of the condition of the oil. The color change as you mentioned is due to buildup from the engine and suspended contaminants in the oil. You would need to send your oil out for an analysis to determine if it was still good. Fleet vehicles and our US government do oil analysis before doing oil changes. If you've ever owned a diesel, you could do an oil change and the new oil would still come out black.