Oil Related Engine Cleaning

[OVERKILL]

Originally Posted By: KrisZ


That is a marketing claim and what I meant as "case on file" is a record of someone actually cleaning up an engine from sludge and varnish just by using synthetic oil.

Second point, that I raised several times when this claim from Mobil 1 is referenced, is that looking at the before and after pictures I don't see any sludge. All I see in the before pictures, especially the oil pick up tube, is a very dirty oil and possibly in a heavy weight that clings to all the parts. I still see plenty of shiny metal and I definitely don't see any crusty sludge formations.
So, just like with any marketing claim, I do not believe it because we are only shown what we want to see.


Of course it is a marketing claim. I see sludge on the left-hand side of the picture (and it isn't all cleaned up in the "clean" picture, but a lot of it is gone).

 

[HangFire]

I'm surprised no one has mentioned PU (Pennzoil Ultra). It is marketed as a strong cleaning oil.

I'm enjoying the debate. I would take the "try something, if that doesn't work, try something else" approach... and change filters often.

 

[stchman]

Originally Posted By: ChrisD46
Just bought a used '02 Trailblazer with the 4.2L 6 cylinder in it and 7 qrt oil capacity . My question is : The engine has moderate sludge and heavy varnish - would it be better for the first few OCI's to use conventional oil with up to 20% MMO OR a good synthetic oil for cleaning ? How to judge how many miles to go for the first few OCI's ?


I would go get some Supertech(or the cheapest 5W-30 conventional you can find) conventional oil and filter.

Change the oil, run it for 1000 miles and then change it again with Mobil 1 and a good oil filter.

 

[Arctic388]

Originally Posted By: HangFire
I'm surprised no one has mentioned PU (Pennzoil Ultra). It is marketed as a strong cleaning oil.

I'm enjoying the debate. I would take the "try something, if that doesn't work, try something else" approach... and change filters often.


I am using PU to try and clean up my sludge monster. see my other comment for documented results i am getting.

 

[nitehawk55]

Originally Posted By: Arctic388
Originally Posted By: HangFire
I'm surprised no one has mentioned PU (Pennzoil Ultra). It is marketed as a strong cleaning oil.

I'm enjoying the debate. I would take the "try something, if that doesn't work, try something else" approach... and change filters often.


I am using PU to try and clean up my sludge monster. see my other comment for documented results i am getting.


Yes and keep us posted on how you're doing with that one please .

 

[fdcg27]

Originally Posted By: KrisZ
Originally Posted By: blackman777
Don't use additives.
They simply aren't needed, especially since oils already have additives.
The synthetic oil will remove the sludge All By Itself without assistance. Just make sure to change it at 1000, then 3000 miles (to remove the loosened-up sludge from the pan).


Total baloney that I see being repeated here to no end. Sure, fresh oil will carry out any loose or soft deposits into the filter or carry it some place else, but it will not clean the engine. Why do people keep repeating this nonsense when there is absolutely no case on record where fresh oil alone cleaned the engine up from sludge or varnish?


Let me put such a case on the record.
Around a dozen years back, I bought a '96 Ody (first gen, really more of a tall Accord wagon than a minivan) with about 110K that showed lots of deposits around the valve gear. It ran great and the VTEC 2.2 was strong, but it was dirty.
The oil I drained out of it smelled badly and was quite thick.
With no more than short (at 2K, real short) OCIs, this engine cleaned up nicely.
Oil alone will clean and the gross deposits will clean up pretty quickly. Motor oil is designed to suspend insoluables and the detergency will both prevent new deposits as well as slowly remove existing ones. The key in a cleanup might be to avoid overcoming the oil's dispersants.
I'd be really wary of putting any solvent in a really dirty engine. Yes, oil screens do plug, with typically disasterous results.
Note also that some of the MMO enthusiasts have never used the stuff in a really dirty engine, since they've never allowed one to get to that state.

 

[nleksan]

As a (bio) chemist I can tell you that esters in particular but also PAO, will absorb petroleum buildup over time, and they WILL clean the engine. I am not going to speculate how long it takes, but I prefer not to let my engine get dirty in the first place.

 

[KrisZ]

Originally Posted By: blackman777
Let me put such a case on the record.
Around a dozen years back, I bought a '96 Ody (first gen, really more of a tall Accord wagon than a minivan) with about 110K that showed lots of deposits around the valve gear. It ran great and the VTEC 2.2 was strong, but it was dirty.
The oil I drained out of it smelled badly and was quite thick.
With no more than short (at 2K, real short) OCIs, this engine cleaned up nicely.
Oil alone will clean and the gross deposits will clean up pretty quickly. Motor oil is designed to suspend insoluables and the detergency will both prevent new deposits as well as slowly remove existing ones. The key in a cleanup might be to avoid overcoming the oil's dispersants.
I'd be really wary of putting any solvent in a really dirty engine. Yes, oil screens do plug, with typically disasterous results.
Note also that some of the MMO enthusiasts have never used the stuff in a really dirty engine, since they've never allowed one to get to that state.


Did the sludge looke something like this:

Or maybe this:

Because if it did, then oil alone would never make a dent in removing the hard, crusted on stuff, only the soft and loose layer from the top. Which would still be a good thing overall. Don't get me wrong, I believe that the cleaning you described did happen, but the deposits in your engine were more than likely soft and not baked on to the metal.

I think that this is the crux of this whole thing. Sludge can be many different things. If it is caught fairly early it will be mostly in gel-like form and not caked on, so it will be much easier removed. Are synthetics better at removing these types of deposits? I seriously doubt it. I believe that any fresh oil will suspend the deposits and carry them out, provided that it is changed early enough so that they don't fall out of suspension again.
However it seems that most people automatically treat all sludge cases the same and I think that is why we have so many believing that oil changes will remove sludge. Sure it will, but only certain types of sludge, the baked on stuff shown in pictures above will remain likely forever unless mechanically removed.


I also strongly disagree that oils are designed to clean up engines. Sure there is plenty marketing material about the subject, but all the standard tests that oils have to pass are about deposit control, not deposit removal. Please point me to materials where it is shown that part of oil design criteria is engine cleaning capability and what are the standardized tests for that.

 

[Shannow]

Originally Posted By: nleksan
As a (bio) chemist I can tell you that esters in particular but also PAO, will absorb petroleum buildup over time, and they WILL clean the engine. I am not going to speculate how long it takes, but I prefer not to let my engine get dirty in the first place.


Given that to lay down the product in the first place, oils had to be oxidatively degraded to the point of saturation, and then the remainder gets dropped out, IMO, the issue takes many oil changes and miles to become a problem.

Given that each new oil change is gathering already deposited sludge, and producing its own, I beleive that you can only do really short OCIs and get the "dissolved" stuff out, small piece by small piece (like it was laid down)

or use some elecrostatic process, or (cooled) depth media to take it out of the circulating stream, allowing the oil to re-gather deposits.

without either, the oil is saturated and can't pick up any more.

 

[Ducati996]

You need to approach this carefully!
You don’t want to be too aggressive so I would use any name brand oil with a new quality filter (Fram Ultra)?? and change it after 500 to no more than 1000 miles. The danger here is loosening up too much sludge to fast and causing the filter to go into bypass, if that happens you could be in serious trouble.
I’ve seen this happen a couple times so don’t get impatient and try to rush the process with solvents & additives, as mentioned it will clean up nicely using quality motor oil.
Repeat the oil & filter change a couple times and extend the drain interval as the engine cleans up.

Ducati996

 

[fdcg27]

That's pretty much what it did look like, and plenty of clean, fresh oil did slowly remove the gunk. It really doesn't take all that many changes and it is certainly safe. I didn't use anything special either, just odds and ends I either had laying around or picked up cheap. This worked for me, although it might not work in every case. Honda engines seem to have enough oil splashing around under the valave cover that they stay clean up there, which may also aid in cleaning up deposits.
Oil does have ample detergency and it also has polarity, although an ester basestock would excel in this over a Grp II, III or IV.
A few short OCIs would be my first resort if I bought a car with an engine showing excessive deposits.
If that produced no visible results, I'd consider either stronger medicine or simply driving and ignoring.

 

[ChrisD46]

Moving forward - would it be better to run a few OCI's with PYB or just move forward with the oil I want to stay with (PP) and just use that moving forward ?

 

[KrisZ]

Originally Posted By: fdcg27
That's pretty much what it did look like, and plenty of clean, fresh oil did slowly remove the gunk. It really doesn't take all that many changes and it is certainly safe. I didn't use anything special either, just odds and ends I either had laying around or picked up cheap. This worked for me, although it might not work in every case. Honda engines seem to have enough oil splashing around under the valave cover that they stay clean up there, which may also aid in cleaning up deposits.
Oil does have ample detergency and it also has polarity, although an ester basestock would excel in this over a Grp II, III or IV.
A few short OCIs would be my first resort if I bought a car with an engine showing excessive deposits.
If that produced no visible results, I'd consider either stronger medicine or simply driving and ignoring.



Good to hear you had positive results.

 

[fdcg27]

PYB is less expensive and has plenty of calcium.
If I were doing short runs, I'd use PYB, or maybe T5.
Probably not worth the extra expense to use PP.
OTOH, if you can pick up either PP or PU at a deal, as some have, why not use it?
If I ran across some almost free VR1, as one member did, it'd be my short OCI cleaning oil for sure.

 

[ChrisD46]

Curious now about the Rotella T5 - does a Heavy Duty Motor Oil such as T5 have a more stout cleaning package than a Passenger Car Motor Oil - such as PYB ?

 

[ChrisD46]

I will update that after adding 9% ~ 10% MMO and driving over 300 miles (mostly highway up to engine temp for 25 miles one way ) - the oil is still clean and no flakes , chunks or any sort of debris to be found . At 9% ~ 10% MMO in a 7 qrt. sump - I don't think I have to worry about a fast & furious engine clean . Yes I will continue to monitor every 100 miles or so and check for any aggressive cleaning indicating the oil and filter should be changed soon .

 

[fdcg27]

The honest answer is that it might.
It will have a stronger dispersement package, though.
This will matter if you really start freeing up debris.

 

[ChrisD46]

I also am curious - any DEXOS 1 rated oil would have a superior cleaning add pack versus all conventionals (PYB) and a lot of synthetics ?

 

[matrass]

Originally Posted By: nitehawk55
Thank you Matrass and TrevorS.... voices of reason .


You are welcome. I was just trying to let the op know that in the same ride my piston slap got a lot louder after using Kreen. not exactly sure what type of crud it removed but the noise is a lot louder after using one small treatment. not having heard of any negative reviews on the site I decided why not try it as my truck was getting close to 100,000 miles. looking down the fill hole it looked very clean before the Kreen as I used mostly M1 and PP for the 5,000 ocis. lots of short trips for my ride and I only put on 10,000 miles per year, so I just change it 2 times per year. I love my truck and once the temp gets to around 150 the sound goes away and it is so quiet. glad to see the OP is taking the slow and easy + monitor approach.

 

[blackman777]

Originally Posted By: ChrisD46
I will update that after adding 9% ~ 10% MMO and driving over 300 miles (mostly highway up to engine temp for 25 miles one way ) - the oil is still clean

You didn't need the MMO.
As documented a few posts above (and in other threads) all you needed was straight oil and more frequent oil changes (1000, 3000, 3000, etc).