is cleaning always a good idea on high mileage engine?

[MrBaumTastic]

Cleaning has risks. If cleaning loosens carbon deposits enough to break loose and circulate in the oil, than can cause problem. A chunk of carbon deposit in a non-critical area might relocate to someplace critical, such as clogging an oil passage or going through the bearings.

For example, an old mechanic friend told me that when he was a kid, detergent motor oil was a new thing. His dad switch the family car from Valvoline non-detergent motor oil to Valvoline detergent motor oil because his dad wanted to clean the engine. A week later their family left WA State to drive to CA on vacation. They made it to Oregon and then their car started making wierd noises that kept getting louder until eventually the car broke down.

A later autopsy of the engine revealed some carbon deposits had broken loose from somewhere and circulated through the oil until they got stuck in the engine bearings where they remained. The bearings were ground up.

Cleaning is not always a good thing.

With that story in mind, if I switch to a higher detergent oil, I change the filter at the time of oil change and change filter again 200-250 miles later. That said, I'm not obsessed with cleaning. I have no reason to go higher detergent than a common modern oil already has.

That anecdote is from what, 30 years ago? Longer maybe? Idk when detergent motor oil was a "new thing".

 

[Carlostrece]

That anecdote is from what, 30 years ago? Longer maybe? Idk when detergent motor oil was a "new thing".

I think anedote occurred in the 1960s or early 70s. Not sure exactly when. The lesson is still valid.

The lesson is that loosening stuck on deposits has risks because it can relocate deposits stuck in harmless places to start circulating in the oil. The deposits might relocate to a harmful location, such as clogging oil channels, cutting bearings, or other. That's ^ a risk if an engine really is dirty prior to cleaning.

Cleaning has some risks. Cleaning is also often unnecessary. That's the lesson and it's still a valid concern.

The OP asked if cleaning is always a good idea. The answer to that is no. It's not always necessary and sometimes isn't a good idea.

That said... The OP's vehicle has had oil changed every 3K miles. It's already clean. If he does waste time and money cleaning it, there won't be any risks for him because it's already clean.

For the OP, why bother to clean an already clean engine?

 

[Lubener]

I still can't figure out why so many are hung up cleaning out their engines which run just fine. The only sure way to a spotless engine is to tear it down which in your case is not worth it.

 

[joekingcorvette]

I would just keep changing the oil on a regular basis. The engine will probably outlast the rest of the vehicle.

 

[OVERKILL]

That anecdote is from what, 30 years ago? Longer maybe? Idk when detergent motor oil was a "new thing".

Detergents started to be popular in the 1950's (but were around longer than that). It was typical for folks to use non-detergent oils on engines without oil filters (they were optional in many applications) so that contaminants generated during use would accrue in the form of deposits and not circulate around the engine. This meant sludge and other deposits were not only common, but expected and considered "normal". This is also from the time period where engines would need regular rebuilds. Oval bores, large ring ridges, massive amounts of blow-by, this stuff was not unusual and I remember seeing it in Auto class in the early 90's, both in our textbooks, and when we tore old stuff down.

ND30 and 40 were popular with the antique boat crowd, so my grandfather and folks like him kept lots of it in stock. Our Y-blocks had bypass filters (optional!) and so we ran regular oil in them. The old Chris-Craft and Chrysler flatheads didn't, so they typically got an ND oil. I even ended up running M1 5W-30 in the hi-po Y-block we had.

 

[ChrisD46]

If you are doing 3K OCI's with decent quality oil, barring a mechanical malfunction, I don't know what there is to clean.

You would think your theory is correct but over time with a GDI engine you may want to add a bottle of Rislone to the oil (every other OCI) to keep rings clean .

 

[MrBaumTastic]

You would think your theory is correct but over time with a GDI engine you may want to add a bottle of Rislone to the oil (every other OCI) to keep rings clean .

So it really cleans that well?

 

[gfh77665]

If I had a 1994 Ford E150 Club Wagon 5.8L with nearly 300K on it, or anything simular, I would not worry about any special cleaning. Just continue regular changes with whatever name brand oil and filter is on sale. Nothing more.

 

[ChrisD46]

So it really cleans that well?

I believe Rislone helps with rings cleaning - I’m in the “it can’t hurt” camp as the ingredients suggest a decent cleaner .

 

[Leroybrown]

If it runs well and doesn't burn oil then what you have been doing works. It doesn't seem there is anything to gain by changing the routine now.

 

[bbhero]

Glad you fessed up --- you have used ALOT of Liquimoly Engine Flush over the years. Lol

I think. There a AA type meeting group for people who use Liquimoly Engine Flush all the time…