Do you really have too......?

[oilpan49]

Since synthetic oil is a very fine, clean and pure oil, is it really necessary to flush out the motor if it's been running on synthetic oil??? Say you use a high quality oil, Amsoil for instance, If you run around like normal and change it out when the oil is hot every like 6K or so, it's not really necessary to flush out the engine is it everyttime you change it, right??? Maybe like once every 30K miles or so to keep the engine spic and span??? Tks guys

AR

 

[47HO]

If you have been running synthetic for the life of the engine, I would see no reason to EVER flush the engine.

 

[Terry]

See my comments on a lubricants ability to clean and lubricate. One aspect is sacrificed for the other.

Many Synthetic oils do run cleaner, but over time the internal combustion engine will accumulate build up at high pressure, hot areas cooking off the oil.

Dispersants will keep the engine at one level of cleanliness but cannot clean through layers of Carbonacous build-up without giving up lubricity in the process.

Another reason Auto-Rx was developed.

 

[TooSlick]

I'd say from personal experience that if you are running synthetic lubes and extremely long change intervals of 20k-25k miles, it is worthwhile to use AutoRX - added to a petroleum oil for 1000 miles - every 100k miles or so. Even with a synlube, you will get some light deposits in areas of the engine where the oil doesn't flow very much and deposits tend to "condense".

TooSlick

 

[MavRick]

quote:

---

Originally posted by Terry:
See my comments on a lubricants ability to clean and lubricate. One aspect is sacrificed for the other.

Many Synthetic oils do run cleaner, but over time the internal combustion engine will accumulate build up at high pressure, hot areas cooking off the oil.

Dispersants will keep the engine at one level of cleanliness but cannot clean through layers of Carbonacous build-up without giving up lubricity in the process.

Another reason Auto-Rx was developed.

---

Terry, some of the synthetics use higher amount of esters than others. Will a high ester based oil do better at keeping the engine clean? I think Auto-Rx is an ester based synthtic formula isn't it?

 

[Pablo]

If you change synthetic oil every 6K miles or so, really there shouldn't be any reason to flush if you used the syn. from the beginning.

I would make exceptions for:

air cooled cars (now really, pablo)
turbos that aren't water jacketed/cooled
Toyota sludge motors
engines that are infamous for sticking rings

Those beasts I would flush at 50K miles "just in case"

 

[buster]

I have run M1 and now Amsoil from 18k miles to 100k miles. I havnt done any inspection for sludge or deposits, but my local Toyota dealer sells BG Engine Flush. They said this brand is excellent and that many other menchanics swear by it. The BG formulation is mild and is less likely to cause seal damage. 4/5 dealers I have been too told me not to bother with any flush if running a high quality synthetic. With a Toyota though, you never know. Check out BG Engine flush. It is a two step process, flush and then a conditioner. I'm not sure if the conditioner should be used if you are using a synthetic oil. BG also has machines, at Toyota, which they use to flush engines out. This is very costly and most likely not necessary. I would go with the can stuff for engine using synthetic. And if Toyota uses it, most likely it is good stuff. The question I have is if you use it, will it hurt the engine seals?

[ December 12, 2002, 09:25 PM: Message edited by: buster ]

 

[oilpan49]

I have not used BG engine flush, The only Engine flush I have used is Amsoil Engine flush, seems to work great at cleaning out all the crap in engines, but I am curious to know if it has solvents in it which can be hard on bearing surfaces. I think I will try Auto-rx next time. I have used synthetic in all my veichles and my mom and dad use it too! We all use and like Amsoil, great stuff!!!

 

[Terry]

Yes the Esters are key to the cleaning aspect of a motor oil, But... if the chemistry is busy being worked to clean you will sacrifice lubricity. In every vehicle I tested the Auto-RX formulation in, syn and non syn oils the oxidation rose during cleaning, nitration dropped during and after treatment, whether the operator could see a difference in the oil color or cleanliness of filters/components etc. Also emissions tests backed this observation up.

That tells me from and analysis point of view that this stuff cleans where normal solvents miss the mark, the rings, valveguides, etc.

My understanding of the esters in Auto-RX is that they are derived are from a natural source. It includes other natural sourced esters that provide lubricity, EP, and some pourpoint help since it gets thick quick in cooler weather.

I do know that the primary esters for cleaning are not found in ANY other automotive application in the world. To be gentle to metal and clean hardened carbon is really amazing to me.

I'm one of the guys a few years ago who would have agree that Amsoil or Redline was the way to keep clean, and was a NO adds kind of guy. Since I have No allegience to any brand including Auto-RX I tell it like I see it tested. So as time moves on and we test more I see things change.

Sorry for the ramble.

 

[oilpan49]

I have heard that using certain engine flushes can blow head gaskets????? Is this true or just BS!??

AR

 

[digitaldrifter91]

i heard that to, thats why i dont use it.

 

[buster]

There are good engine flushes that won't harm your engine, BG being one of them. Like i said, if Toyota uses it, it most likely is good stuff.

 

[Pablo]

Flushes: I think that if you dump too much of any non lubricant (read: solvent) in your engine you will do harm. That said I haven't heard specifically of anyone harming an engine with Amsoil flush. I have used it a couple times in the turbo. Although people will rip a seam sometimes when you mention solvent flush - I really think the better brand, IDLE only types are harmless.

Truth? Here's what I have witnessed: A unnamed person used BG flush and got the bright idea to drive with it the car. The car was not a known sludge producer - person went 3.5k+ miles. Car had serious lower end issues....Moral? Follow directions!!!!!!!!!!!!!!

 

[metroplex]

why even waste money on these new fangled flushes?

Just buy a quart of ATF (any type/brand will do) and dump it in (drain out about a quart of engine oil first). There will be enough viscosity/lubricant in there to keep your engine lubed properly for a 50+ mile drive.

The main component in ATF is a detergent based compound that will clean the insides of your engine.

Other than that, synthetics themselves clean engines better than dino lubes. I saw the Group III 10W-30 I used in my 5.0 literally take the sludge out of the valve covers right on the spot. As I poured it in, whatever hardened brown deposits there were started to peel right off.

 

[oilpan49]

uuuuuuhhhhhh?????? ATF is a hydraulic(sp?) fluid. I have never heard using ATF fluid to flush out an engine, interesting remedy though???

 

[OneQuartLow]

This keeps reappearing.

ATF cleans some deposits well, but not all, and it'll leave its own deposits that will require another cleaner. Keep it for the transmission.

David