Does good cleaning = good wear protection?

[actionstan]

I see several threads where we discuss how clean an engine is after x amount of miles, or recommending certain oils for cleaning a dirty engine (Pennzoil!).

But.. I got to thinking.. just because an engine is clean? Does that necessarily mean that the oil has also done a good job of lubricating the engine and protecting it from wear? It seems like a high level of detergents and dispersant is what would clean and engine and keep it clean, but the anti-wear additives would keep the engine protected.

Is there any cross over here? Is it possible to have a spotless engine, which has worn quicker than it should have? One reason I ask is the oil in my Kia always has a very strong fuel scent. I have been running Pennzoil and Mobil1 for 7500 mile intrevals, mainly interstate driving, it gets gas mileage within its estimated rating, the engine also looks spotless from the fill hole and there are no drivability issues, currently the car is at 36k miles, Ill have a even better idea of how clean it is when I open the valve cover at 60k to check valve clearances.

Let me know your thoughts on cleanliness vs wear, thanks!

 

[Quattro Pete]

Originally Posted By: actionstan
Is it possible to have a spotless engine, which has worn quicker than it should have?

Sure... I mean, if you clean something too aggressively, you could actually damage it, wear it out in the process of cleaning. Kind of like scrubbing your dirty pots too much.

Alas, I'm not saying oil cleaning additives are really so strong as to do damage.

But back to your first question, yes, typically one set of additives is responsible for cleaning, and another for wear protection. A good oil needs the right combination of both.

 

[Quattro Pete]

Originally Posted By: actionstan
One reason I ask is the oil in my Kia always has a very strong fuel scent.

DI engine? Turbo?

These often produce higher than normal fuel dilution, and hence the smell. It really does not take much fuel in oil for it to have a strong fuel smell.

 

[tig1]

Auality oil will do both. That's why I have used M1 for the last 36 years.

 

[yvon_la]

yes there is such a thing as too clean an engine!but as far as I saw the issue come normally from fuel as far as I saw (exemple:biodiesel or x % ethanol gas,x being usually in the 5% or more range)but in oil?maybe not sure

 

[demarpaint]

Originally Posted By: actionstan
I see several threads where we discuss how clean an engine is after x amount of miles, or recommending certain oils for cleaning a dirty engine (Pennzoil!).

But.. I got to thinking.. just because an engine is clean? Does that necessarily mean that the oil has also done a good job of lubricating the engine and protecting it from wear? It seems like a high level of detergents and dispersant is what would clean and engine and keep it clean, but the anti-wear additives would keep the engine protected.

Is there any cross over here? Is it possible to have a spotless engine, which has worn quicker than it should have? One reason I ask is the oil in my Kia always has a very strong fuel scent. I have been running Pennzoil and Mobil1 for 7500 mile intrevals, mainly interstate driving, it gets gas mileage within its estimated rating, the engine also looks spotless from the fill hole and there are no drivability issues, currently the car is at 36k miles, Ill have a even better idea of how clean it is when I open the valve cover at 60k to check valve clearances.

Let me know your thoughts on cleanliness vs wear, thanks!


You mentioned a strong fuel scent. Keep in mind gasoline does a pretty good job of cleaning dirty engine parts, certainly not something I'd want to add to my oil though. I'd do a UOA and determine just how much gas is in the oil and rule that out as a possible problem.

 

[3800Series]

I know in worn out engines carbon and junk can actually help improve compression and cleaning them a lot can actually have negative effects on the engine.

 

[route66mike]

MolaKule pointed out a while ago that additives can compete with one another. As in anti-wear addtives may not like to have more detergents hanging around to work best and vice-versa.

 

[actionstan]

Originally Posted By: Quattro Pete
Originally Posted By: actionstan
One reason I ask is the oil in my Kia always has a very strong fuel scent.

DI engine? Turbo?

These often produce higher than normal fuel dilution, and hence the smell. It really does not take much fuel in oil for it to have a strong fuel smell.


This is a port injected naturally aspirated engine, no DI, no turbo, and no supercharger.

 

[bubbatime]

If your used oil smells strongly of fuel, you might want to try shorter intervals, in my opinion. Some engines dump more fuel into the oil than others.

 

[OneEyeJack]

Sludge in the presence of moisture is acidic and that kind of stuff does not lubricate as well as engine oil. Things to watch out for when getting rid of sludge are glycol, fuel and water. If you're going to clean out a "dirty" engine you should take your time, get involved, check things, change the oil and filter more often and use something that goes at it carefully like Auto-Rx. Any kind of solvent left in an engine is too much of a risk for me. I'm not smart enough to figure out how much is enough and it's too easy to overdue it. And all this only applies if you're going to keep the car. Otherwise, who cares. You're going to get something else before the sludge does any real damage unless is't so bad it becomes a deal breaker.

 

[dparm]

Eh, the human nose is ridiculously sensitive when it comes to detecting odors. Just because you smell some gas doesn't mean there is a ton of it.

My brother (chemist) once told me the human nose can detect some compounds of just a few parts per BILLION.

 

[SteveSRT8]

Originally Posted By: dparm
Eh, the human nose is ridiculously sensitive when it comes to detecting odors. Just because you smell some gas doesn't mean there is a ton of it.

My brother (chemist) once told me the human nose can detect some compounds of just a few parts per BILLION.


I have always been amazed by these folks who can smell, see, taste, or whatever, the differences in their oil.

Especially gasoline. Almost any engine will eventually yield oil that smells like gas if you leave it in long enough, and some hi performance tunes really dilute the oil quickly with fuel.

Yet we have virtually no real evidence of harm from some fuel dilution...

 

[LotI]

Originally Posted By: dparm
Eh, the human nose is ridiculously sensitive when it comes to detecting odors. Just because you smell some gas doesn't mean there is a ton of it.

My brother (chemist) once told me the human nose can detect some compounds of just a few parts per BILLION.

Yup. The gas man told me that our noses are more sensitive than their sniffing equipment. The sniffer does better finding exactly where the leak is.

 

[chrisri]

Originally Posted By: bubbatime
If your used oil smells strongly of fuel, you might want to try shorter intervals, in my opinion. Some engines dump more fuel into the oil than others.


+1. You should also look at various sensors around your motor: lambda sensor, tps, icv and temperature sensor.They all can cause engine running rich.

 

[2KBMW]

Originally Posted By: route66mike
MolaKule pointed out a while ago that additives can compete with one another. As in anti-wear addtives may not like to have more detergents hanging around to work best and vice-versa.


+1 I was thinking the same thing. So Pennzoil will cause more engine wear?