Clean Oil 101

Turbo Steve

Top Post Dawg
Joined
Jan 11, 2000
Location
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Controlling engine oil contamination will enhance your TDI engine's expected service life more than any other wear factor, even more so than one's choice of motor oil (although this is important too.) Instead of focusing on whether Delvac 1 is better than Series 3000 (both excellent oils which I endorse), perhaps we should set our sights even higher towards our TDI's filtration systems.

Regarding the 1.9L's filtration systems, of primary concern is dirt and debris in the range of 2 to 15 microns, which cause havoc and eventual death to any engine's internal components. There are two considerations which I put forth for your review:

1. Keep dirt and debris out to begin with - Air Filtration
2. Filtering dirt and debris efficiently after it gets in the oil - Oil Filtration.

Using high quality filtering products on both counts, will add up to fewer oil changes and less engine wear because the cleaner the oil is, the better the seal will be between the piston rings and the cylinder wall, thereby resulting in lower oil consumption and less blow-by getting into the crankcase to contaminate the oil.

Our TDI engine needs clean oil all the time, and in order to help you understand why contaminants can harm your TDI engine, let's review a few of the principle functions of oil and why it's important to keep it clean:

The Primary Functions of Synthetic Diesel Oil in a TDI Engine

Synthetic Oil Seals - Synthetic oil creates a seal between the moving piston rings and the adjacent cylinder walls, and between the valve stems and the valve guides. This "sealing" action keeps the synthetic oil out of the combustion chamber and also the combustion blow-by-gasses out of the oil in the crankcase. Hence, the better the seal, the more power is transmitted to your crankshaft and naturally the greater the TDI engine's efficiency.

Synthetic Oil Cools - Temperatures within the combustion chamber of a diesel engine get very hot and the antifeeze coolant within the Cooling System is asked to carry away most of this heat. One lesser-known function of the TDI engine's Cooling System is that of the synthetic oil, as it cools the cylinder walls, the pistons and rings, the crankshaft and bearings, and all other internally moving parts. In short, synthetic oil cools about 25% - 30% of the TDI engine and the antifreeze coolant does the rest. Without the cooling properties of oil, your TDI engine would run red-hot and quickly seize up.

Synthetic Oil Cleans - One of a synthetic oil's most basic functions is to help keep our TDI engine clean. As an example, carbon deposits are constantly being formed on the cylinder walls and can buildup very quickly if the Injection Timing is off or poor quality diesel fuel is used. Naturally, the pistons and rings, which move on a thin film of synthetic oil, tend to remove these carbon / blow-by deposits in a squeegee-like action or in a similar manner as a windshield wiper-blade cleans the windshield. Obviously, this squeegee-like action of the piston rings pushes a small amount of oil upward to be burned in the combustion chamber, and in it's downward motion, pushes these carbon / blow-by deposits back into the oil pan, creating soot and other harmful contaminants.

Synthetic Oil Lubricates - Maintaining proper lubrication is important for the efficient operation of our TDI engine. As a lubricant, a Group IV / V synthetic diesel oil actually decreases the power required to overcome friction and easily reduces wear or rubbing between bearing surfaces.

Proper lubrication in our TDI engine will result in increased power and longer engine life. If it were possible to keep our synthetic oil 100% clean (along with adequate oil pressure), there would always be a thin film of oil between bearings and journals, and there would be no engine wear because of no contaminants present in the oil. Obviously, no oil and no filtering device is perfect and our TDI engine slowly wears out, but over a course of 300,000 + miles.

Moreover, one of the chemical properties of a synthetic oil is it's viscosity or thickness. The viscosity of an oil is a measure of its fluidity or resistance to flow or "fluid friction", as some put it. With all other things being equal, it is the viscosity of a synthetic oil that determines the friction loss, the amount of heat generated, the mechanical efficiency, the load carrying capacity, the film thickness, or the amount of wear an engine undergoes. Clean lubricating oil must be free of as much contamination as possible in order to perform it's job in the most effective manner possible.

In summary, only "clean synthetic oil" can seal, cool, and lubricate our TDI engine for maximum durability and peak efficiency. All automotive and lubrication experts agree that clean synthetic oil performs these four functions (as outlined above) better than dirty oil.

When we want to wash our clothes, we don't use dirty water, ... do we? (A couple of you characters might, but I don't.
) Likewise, we shouldn't be using dirty synthetic oil to clean the carbon or blow-by from the cylinder walls.

Clean oil will remove dirt better than dirty oil, and using the best air, fuel, and oil filtration devices available give clean synthetic oil a major head start in: 1. sealing, 2. cooling, 3. cleaning, and 4. lubricating our high-performance TDI diesel engine.

[This message has been edited by Turbo Steve (edited February 03, 2001).]
 

Turbo Steve

Top Post Dawg
Joined
Jan 11, 2000
Location
.
Normally I don't ask folks to air their dirty laundry, but out of curiosity, how is your oil holding up?
 

Bad Karma

Well-known member
Joined
May 27, 2001
Location
Monmouthshire, UK
Looking after engines is something I belive passionately in. In my situation however I do not buy new cars. I prefer older, more obscure cars which people will notice more. The type of car I am looking at presently will come with 100k on the clock already.

I know that better late than never applies. But with this mileage and having been maintained normally is it fair to assume that the damage will have begun and that stringent oil decontamination measures will not be worth the trouble. What I am asking is that if wear is present already, is it possible to prevent it going further?

I have been reading the threads about stationary by pass filtering and would like such a device. Would it be worth building one for use on an old car. Obviously if the engine was treated to a full rebuild the answer would be yes. OK, the economics would dictate that if such a machine can gain an extra 20k from a car then it is worth it. I however like to drive a car knowing, in theory at least, that it should last indefinately.
 

TooSlick

Top Post Dawg
Joined
Dec 2, 1999
Location
Dixie
TDI
Audi 100S
Bad Karma,

Wear is a continual process ...even the best synthetic oil and filtration system cannot turn back the clock, but you can certainly slow down the wear rate from the time you install a by-pass filtration system and upgrade your oil.

Unless the engine is really shot and burning significant amounts of oil, I think this is a worthwhile improvement. I just purchased an Amsoil by-pass filtration kit to install on my 1990 Audi 100 - it has 185,000 miles on it!

TooSlick
 
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