Why should you never drive with an engine flush in?

[JT20]

Been thinking about this. What are the dancers of having a flush product in the oil for longer than it says, wouldn't it all get filtered out anyway?

Assume (added into the) dirty oil that's coming out (of the engine anyway, before changed,) something like adding it from the store after work (engine warmed up) before you go home to change it.

Edit. Dangers not dancers

 

[Pablo]

At best follow the instructions. Most flushes are idle only (no load on engine) and most drop the oil viscosity. They are not filtered out (?)

Oil flushes have a specific usage/place. Why do you need a flush?

 

[JT20]

At best follow the instructions. Most flushes are idle only (no load on engine) and most drop the oil viscosity. They are not filtered out (?)

Oil flushes have a specific usage/place. Why do you need a flush?

Well, I am over-thinking this engine noise. (This only on every other start up noise that is not present when the engine is running, specifically.) What if whatever oil passage that directs oil to my filter is plugged up. It may or may not be the case but, I am asking myself if more oil should be coming out when I take the filter off (which is very easy to get to.)

I did intend this as a more general thread but I could use why I'm even thinking about it on mine for the context, sure.

 

[WylieCoyote]

The particles of sludge it loosens will get caught by the filter, down to a certain micron in size, depending on the filter, but the product itself will remain in the oil, and therefore, in the engine, until you drain it. I'm no chemist, but anything that isn't engine oil isn't a lubricant, which is why I won't use flush products or 'cleaners'. I prefer to let high-detergent synthetic oils do the work. IMO, solvents are the opposite of oils, and will break down the components of the oil that are supposed to be protecting the bearings from metal-to-metal contact. I can't recommend flush products at all, and I certainly can't recommend leaving them in longer than prescribed.

 

[wpod]

The flush reduces the lubricating capability of the oil

 

[toneydoc]

Dont do it

 

[BISCUT]

I don't believe there are many uses for MMO in modern engines or gas tanks but a slow clean in the engine is one. I am running 3k OCI with ST and some MMO for the last 500 miles in a Sentra with 160k miles I picked up. I'll do that for 2 or 3 OCI's then change filter and move to ST and 5k changes. I can't speak for others but going slow without a flush in the way I described makes me feel better.

 

[rob1715]

The particles of sludge it loosens will get caught by the filter, down to a certain micron in size, depending on the filter, but the product itself will remain in the oil, and therefore, in the engine, until you drain it. I'm no chemist, but anything that isn't engine oil isn't a lubricant, which is why I won't use flush products or 'cleaners'. I prefer to let high-detergent synthetic oils do the work. IMO, solvents are the opposite of oils, and will break down the components of the oil that are supposed to be protecting the bearings from metal-to-metal contact. I can't recommend flush products at all, and I certainly can't recommend leaving them in longer than prescribed.

Exactly. Why do you want to flush? Modern oils are getting better each year, and flushes are normally due to a lack of maintenance. A bottle of something won't save a piece of machinery that has not been maintained. That a westernized way of thinking. And if anyone is buying a vehicle that needs a flush, why buy it? It hasn't been maintained.

 

[JT20]

This would be the stuff https://www.amazon.com/Niteo-Motor-...words=gunk+engine+flush&qid=1606235126&sr=8-5

I'm paranoid over an ADBV sound.

Not even in the oil before it is changed?

 

[WylieCoyote]

If you have so much sludge that you feel it is getting ready to do more damage than a flush, maybe you should consider a teardown. Things go from bad to worse quickly inside a sludgy engine when you introduce a flush. Plugged oil passages will make you wish you hadn't messed with it. Your insistence on a flush gives the impression you've got something serious going on, so please share the circumstances with us.

 

[demarpaint]

Oil is thinned considerably, as a result protection is compromised, especially if the engine is under load.

 

[JT20]

If you have so much sludge that you feel it is getting ready to do more damage than a flush, maybe you should consider a teardown. Things go from bad to worse quickly inside a sludgy engine when you introduce a flush. Plugged oil passages will make you wish you hadn't messed with it. Your insistence on a flush gives the impression you've got something serious going on, so please share the circumstances with us.

Not really an insistence, just that this ADBV noise has me freaking out.

I'm about to just change all the oil Full Synthetic 5W-30, have to decide on one Just May use Mobil 1 because it's either that or SuperTech full syn... And have this noise done away with.

Might even choose M1 0W-30 AFE.

Come to think of it.. while Supertech Full Synthetic 5W-30 likely would be just fine, I've never actually tried Mobil 1 oil so this could be my shot.

M1 0W-30 AFE.. A good choice?

 

[ABN_CBT_ENGR]

Not really an insistence, just that this ADBV noise has me freaking out.

Partner listen, you are making an unqualified GUESS as to the noise and possible remedy which personally I doubt has anything to do with the noise.

Before you start throwing ideas (and money/time) at it, get it properly diagnosed.

You don't need an engine flush either.

 

[JC1]

You need to stop fretting about the noise and trying to see if a flush fixes it. What vehicle is this and how long have you owned it and has the maintenance been done at proper intervals?

I would cut open the oil filter once it's removed to see how much crud is in the filter. If you are as paranoid as I think you are, I'd remove the valve cover/s and see what the condition of the motor is.

 

[JT20]

I solved the problem.

I did not use a flush.

Tomorrow morning for sure, I'll know I am full blown paranoid lol.

 

[JT20]

Kind of surprised nobody asked me what I did.

Well I am eating dinner. Then I go outside and finish it up.

Im still not sure why it stopped doing what it did because of what I did, and obviously it's not first start tomorrow morning yet but I just drove around like 9 miles or so and I do believe I got it licked...

Now to share what dinner is ..

 

[TiGeo]

Oil is thinned considerably, as a result protection is compromised, especially if the engine is under load.

This. Really that simple. Follow the directions.

 

[JT20]

I ended up NOT doing the flush.

I have 90-95% NEW oil in there, with wonderous and good/great results.

Oddly enough, it is when I filled past the full mark on my dipstick and in the sump that the problem went away.

One good drive to work and it may have been eliminated.

I did do Mobil 1 0W-30 (4 quarts) and I had a quart of Mobil 1 15W-50 on hand so I put that in to do the overfull, which weirdly has seemed to solve the problem.

I put the Fram Ultra in about 100 miles ago, maybe slightly less than that...

I can mail my filter to 53' Stude when the car hits ohhh 165,000 miles (presently at 162,875 miles, this is a Subaru EJ 2.5) if you like and if that is cool with him

Did I mention the weird ADBV issue is solved?

Maybe it happens less with a smaller filter ....

 

[Kira]

Your posts were a crazy jumble of disjointed sentences.
Was this your first oil change in this car?

How on Earth did you settle on a noise your engine being an "ADBV noise"? That'd be a first.
An ADBV is a pliable flap washer which is supposed to prevent back-flow upon shutdown. One making noise has never been mentioned.
One thing I believe is that some work better than others.

Those 2.5l Subaru engines are known for the noises they make. And thank you for taking 18 posts to tell us what engine you have.
Any chance of telling us the year of your car or how old it was when you got it or if you know it's service history?
Details in thread starting posts really help.

A pal bought a noisy 2001 Forester from a neighbor. It didn't have 60K on it but was a typical "bad Subaru".
He indulged a lifelong dream to solve engine noise by filling the crankcase with transmission fluid and letting it idle for 15 minutes. It didn't change a thing.
I told him that the harsh solvents of earlier fluids had been omitted decades earlier. I learned that here. He did it anyway.

A word on ADBV if I may.
We had a run of the Saab 2.3l 4 cyl. engines in my extended family. The spin on (aka canister, aka can) filter was side mounted on the block.
LOTS of oil changes were done on those 7 Saabs over 18 years.
When you unscrewed the filter, the oil in the top of the engine would drain out. It had been held there by the ADBV obviously.
Sometimes the ADBV worked and sometimes it didn't. If no oil followed removal of the filter it's safe to conclude the ADBV didn't do it's job.
Note: I always performed oil changes on a warmed up/recently shut-down engine so there was no chance of "overnight leak down" or some such.

I didn't have resources to set up an experiment involving every brand of filter out there but I can tell you the AC-Delco product worked every time. Others would too. Some appeared to have no ADB effect.
Using a Subaru filter in your Subaru is smart. Fram Ultras are ultimately praised here. I use one on my truck.
Some later Subaru models have high mounted filters so any ADB function is accomplished from within.

Some oils are "quieter" than others. There's a lot to know.

 

[JT20]

Your posts were a crazy jumble of disjointed sentences.
Was this your first oil change in this car?

How on Earth did you settle on a noise your engine being an "ADBV noise"? That'd be a first.
An ADBV is a pliable flap washer which is supposed to prevent back-flow upon shutdown. One making noise has never been mentioned.
One thing I believe is that some work better than others.

Those 2.5l Subaru engines are known for the noises they make. And thank you for taking 18 posts to tell us what engine you have.
Any chance of telling us the year of your car or how old it was when you got it or if you know it's service history?
Details in thread starting posts really help.

A pal bought a noisy 2001 Forester from a neighbor. It didn't have 60K on it but was a typical "bad Subaru".
He indulged a lifelong dream to solve engine noise by filling the crankcase with transmission fluid and letting it idle for 15 minutes. It didn't change a thing.
I told him that the harsh solvents of earlier fluids had been omitted decades earlier. I learned that here. He did it anyway.

A word on ADBV if I may.
We had a run of the Saab 2.3l 4 cyl. engines in my extended family. The spin on (aka canister, aka can) filter was side mounted on the block.
LOTS of oil changes were done on those 7 Saabs over 18 years.
When you unscrewed the filter, the oil in the top of the engine would drain out. It had been held there by the ADBV obviously.
Sometimes the ADBV worked and sometimes it didn't. If no oil followed removal of the filter it's safe to conclude the ADBV didn't do it's job.
Note: I always performed oil changes on a warmed up/recently shut-down engine so there was no chance of "overnight leak down" or some such.

I didn't have resources to set up an experiment involving every brand of filter out there but I can tell you the AC-Delco product worked every time. Others would too. Some appeared to have no ADB effect.
Using a Subaru filter in your Subaru is smart. Fram Ultras are ultimately praised here. I use one on my truck.
Some later Subaru models have high mounted filters so any ADB function is accomplished from within.

Some oils are "quieter" than others. There's a lot to know.

Hi Kira. Yes, a lot of firsts. First oil change, yes that is true. (To me on the car. It sat awhile) First Subaru. First time using Mobil 1. First Fram (Ultra.) First Fram before that. First new oil filter on it before that. First time thinking of using an engine flush product, as opposed to transmission fluid or other solvent. So more than a few firsts.

I have a 2000. I believe they call it an EJ251. No head gasket problem so that's good ..

This filter mounts vertical, straight up and down. Presently got the Fram Ultra on it. Previous filters, I had a car with a canister filter.. on the top. Always messy. Also had a truck with it remote-mounted. Not sure the last time I had one where it was on the side.

I at first thought maybe there was a ADBV issue, then perhaps a PSID drop issue, as filter size, as mentioned, the greatest the size, the longer oil should take to fill it. Now, gravity helps this one fill; it has to fight gravity to come back up to lubricate.

If the ADBV was maybe stuck closed and causing the initial lack, that is what made me flip out and think oh, there is a problem. Sounded like rod knock. Sounded the same as the Piston Slap (much more likely what it was) because lifter tick has pretty much gone away. Which lead me to come and ask the question, and I chose to trust wisdom and not use the flush.

Quick summation, somehow someway, an overfill condition has appeared to quiet the noise. I then thought maybe I had a oil lubrication/lubricity issue. Mobil 1 in for less than 100 miles and I'm noticing the engine seemingly shut off smoother; which also probably makes no sense.

But I believe it is cleaning sludge.

Will look for the color of the oil when I get home.. all good?

Was this your first oil change in this car?

Yes, it was.

Yesterday was Oil Change #1. 162,875. Filter changed Fram Ultra ~162,800.

No large chunks came out. I don't think I saw any, actually. Maybe some small ones but not for certain. Oil smelled a little more like gas than I would have liked but it is a new fill in there now, as mentioned, primarily Mobil 1 0W-30.