How well do synthetic oils clean engines?

[skaughtz]

When I purchased my '07 Camry it had about 60k miles on it and a sticker from a lube shop stating it had conventional oil in it. The specs for the car call for 0/5W-20 full synthetic, so I changed out the oil and put in PP 0W-20. I had read that PP is supposedly a great oil for cleaning out your engine of varnish. Recently I did a pre-vacation trip tune up on the car and replaced the oil with PP 0W-20 again after a 4,200 mile OCI (the first since I originally replaced with PP). What came out looked exactly like conventional oil. Slightly thick and black.

As I just can't justify spending $30+ dollars on an oil filter cutter, I'm assuming the filter did its job. I'm also assuming that for the majority of the 60k miles prior to me having the car, conventional was being used. What I am curious about is if anyone else has seen how well synthetics clean out engines in a similar state over a longer period of time than my short OCI. Also, if there is a specific synthetic that I may want to try to help clean it up a bit. I'm not really concerned about any damage (so the conventional vs. synthetic debate doesn't need to be had), but I do like seeing clean fluid going in and coming out. It gives me that warm fuzzy feeling.

 

[Quattro Pete]

PP and PU are supposed to be pretty good at cleaning, but there is only so much any oil can do. And it's not actually the base oil but the additive package (detergents) that is responsible for cleaning.

Quote:
What came out looked exactly like conventional oil. Slightly thick and black.

Well, that's good. That means it's doing some cleaning, IMO.

Of course some oils will turn black regardless. That's just a result of additives being subject to high temperatures.

 

[GMBoy]

The cleaning of your engine will be a slow process over several oil changes. Even then, it will not clean up everything.

 

[NMBurb02]

Originally Posted By: skaughtz
... but I do like seeing clean fluid going in and coming out. It gives me that warm fuzzy feeling.

Clean fluid going in is good but if you want the oil to do some cleaning, don't expect it to come out clean. As the oil cleans the engine, anything too small to be captured by the filter will be held in suspension and discolor the oil. Clean oil coming out means that it did not do much cleaning or there wasn't much to be cleaned up.

 

[WobblyElvis]

Nothing special is needed. If the engine does have sludge build up, you want to remove it slowly. Use any synthetic of the correct grade and change it at reasonable intervals and you are done.

 

[HerrStig]

Originally Posted By: skaughtz
When I purchased my '07 Camry it had about 60k miles on it and a sticker from a lube shop stating it had conventional oil in it. The specs for the car call for 0/5W-20 full synthetic, so I changed out the oil and put in PP 0W-20. I had read that PP is supposedly a great oil for cleaning out your engine of varnish. Recently I did a pre-vacation trip tune up on the car and replaced the oil with PP 0W-20 again after a 4,200 mile OCI (the first since I originally replaced with PP). What came out looked exactly like conventional oil. Slightly thick and black.

As I just can't justify spending $30+ dollars on an oil filter cutter, I'm assuming the filter did its job. I'm also assuming that for the majority of the 60k miles prior to me having the car, conventional was being used. What I am curious about is if anyone else has seen how well synthetics clean out engines in a similar state over a longer period of time than my short OCI. Also, if there is a specific synthetic that I may want to try to help clean it up a bit. I'm not really concerned about any damage (so the conventional vs. synthetic debate doesn't need to be had), but I do like seeing clean fluid going in and coming out. It gives me that warm fuzzy feeling.
Never affirm, seldom deny, always distinguish.

 

[zach1900]

Some might say that certain conventionals have better solvency. Really. Top conventional oil like PYB are better than some blends and full syns.

 

[zach1900]

I didn't know the 2007 called for syn

 

[KCJeep]

There is a good bit of evidence syns keep an engine cleaner with proper intervals. Very little to none IMO that they clean a dirty engine any better than anything else.

Doesn't sound like your engine is very dirty anyway, continued use of the PP at proper intervals is likely all you need to acheive the results you seek.

 

[HangFire]

I wouldn't expect an engine with 60K to be that dirty, even if conventional was used.

 

[mongo161]

Originally Posted By: zach1900
Some might say that certain conventionals have better solvency. Really. Top conventional oil like PYB are better than some blends and full syns.


+1....5k intervals will help clean up any engine.

 

[BikeWhisperer]

Originally Posted By: HangFire
I wouldn't expect an engine with 60K to be that dirty, even if conventional was used.


The other thing lube shops do besides use conventional oil is continue the 3k, 3 month change interval myth.

If this engine used SM and SN conventional oils at anywhere near that change interval then I doubt the engine has any significant deposit issues.

 

[Kuato]

Sounds normal, like the PP is cleaning things for you.

 

[Oro_O]

Originally Posted By: NMBurb02
Clean oil coming out means that it did not do much cleaning...


Important point. Had them same experience.

We bought a used Lexus. The window sticker was from a quick-change shop that put generic bulk 5w-30 in it. I drained it after 3k miles and it looked quite fresh. I put in Pennzoil Platinum HM 5w-30, which turned darker in 500 miles than the bulk shop oil had in 3k. I was pleased with this result and felt confident the PP was doing what it was supposed to.

PS, there's no need for a purpose-built cutter. Just pick up an angle grinder with a cut-off disc on it (or put one on a drill, etc.). This doesn't have to be a precision operation...

 

[skaughtz]

Originally Posted By: Or
PS, there's no need for a purpose-built cutter. Just pick up an angle grinder with a cut-off disc on it (or put one on a drill, etc.). This doesn't have to be a precision operation...


I don't often facepalm myself, but wow, I can't believe I was that stupid, haha. Thanks man

 

[Shannow]

Typical synthetic oils (GrIII and GrIV) have little polarity, and poor solvency.

As a result, "synthetic" oils per se IMO aren't a valuable cleaning product for an engine...the finished package may be with better detergents/dispersants, and the better oxidation resistance of those base oils may mean less self made junk for the oil to deal with during an OCI.

 

[bbhero]

PYB ??? A good choice maybe

 

[Brad_C]

Originally Posted By: bbhero
PYB ??? A good choice maybe

Why is it any time someone mentions the word "clean" someone else goes "PYB", like it's the universal solution to engine cleaning and obviously available all over the world?

Shannow posed a well reasoned question about synthetic oils. "PYB" is not an answer, and particularly as he (and I) live in a hemisphere where "PYB" is not available, not even relevant.

Now I've got that off my chest, my completely unfounded theory is it would seem that its a balance between an additive pack that is probably similar to that found in regular oil combined with the synthetic that leaves less behind. So it takes out more than it leaves and by that action "cleans".

My personal experience has been an engine I bought at 400,000k that had obviously been run on years of conventional oil and a lax change schedule. No sludge as such but plenty of grunge and varnish. 50,000k of Mobil 1 has made a noticeable difference to the cleanliness inside the block as observed with a borescope through the crankcase ventilation holes. Can't comment on the head being cleaned as I rebuilt it when I got the car, however it is still sparkling inside whereas before I rebuilt it the lifter valleys were highly varnished.

I suppose it's all about detergent in the add pack, but I don't really know. In another similar motor that had about 500,000k on it I wasted some money on AutoRx. Mobil 1 had better results long term.

 

[wemay]

Is varnish ALWAYS a precursor to sludge? Some will say varnish is much-to-do-about-nothing and other's will opine it's a sign of coming troubles. I think, depending on the engine platform and maintenance history, the answer falls somewhere in the middle.

 

[Quattro Pete]

Originally Posted By: Brad_C

Why is it any time someone mentions the word "clean" someone else goes "PYB", like it's the universal solution to engine cleaning and obviously available all over the world?

Nobody said that PYB is available all over the world. The OP is in the US, so he received a US-based answer. If we only had to stick to products that are available all over the world, the options would be very limited. If you would like to ask what these options should be in Australia, you are most welcome to start your own thread.