Flush Engine Before switching to Synthetic

[checkitout]

Just purchased a 1995 es300 and it is due for an oil change, I'm going to switch to Valvoline maxlife synthetic 5w-30w and use thier new maxlife oil filter (the car has 81,500 miles on it)
I've read here and on other forums that you shoul flush the engine befor switching to a synthetic oil.
If this is so any sugestions as to what flush to use and anyone had any experience with the maxlife synthetic oil or filter? As a side note he had the dealer do his oil changes and used quaker state dino oil ( he had the 250,000 mile waranty from quaker state,but it reads use chage oil every 4,000 miles and he's slighly over that now--so they would not honnor the waranty now--i'm assuming)

 

[Quest]

naaah! I wouldn't "flush" the engine with anything but the following (if you really want to "flush" it, which I pretty much doubt the need for that): AutoRx, or HDEO/XD-3 oils.

Ordinary "flushing" calls for harsh solvents (kerosene, paint thinner or Stoddard sovents,etc) are extremely hard on engine seals such as crank/cam seals, valve guide seals,etc. The swelling will definitely ruin the seals no matter how short the flush duration is.

Worse yet: harsh solvent has the tendency to break loose large chunks of sludge or carbonacious debris during the cleaning process and when those debris ended up in your sump pan, it will clog your oil pickup screen and starve your lubrication system to death. Next thing you know: 5 miles down the road after you performed a 10 min flush, your oil light came on and you spun a bearing or 2 due to oil starvation (good luck try claiming warranty with that!)

The best way to "flush" your engine is to resort to using AutoRx or use high detergency motor oil such as HDEO or XD-3.

Do it the gentle way, or none at all. That is my take to your situation.

 

[pitzel]

I concur, pop over the border sometime and stock up on XD-3 0W-30. 81k miles on 4k mile changed dino shouldn't be a problem, even Quaker State dino.

Don't bother with flushes, etc.

 

[BlazerLT]

Yes, flush before the switch.

 

[pscholte]

I initially interpreted your question as meaning, "Do I need to do a special flush in order to change to syn oil?" If that is what you are asking, "no, you don't." If you meant a flush for cleaning purposes, you can if you want. Please see below.

I will bet if you ask all the major oil companies if you need to flush (in order to make the switch), you will get an overwhelming "No, No, No" I'll do a quick check but I think you are wasting time and money, unless you just want to clean the engine before you put in syn.

From the Mobil1 website FAQ: (I believe they intended this question to apply to all versions of M1 as it is not repeated in the "regular M1" section.)

Do I need to flush my engine before switching to Mobil 1 Extended Performance?

You do not need to flush your engine prior to changing to Mobil 1 Extended Performance

From the Pennzoil website: Synthetic motor oils can be used occasionally or regularly.

Do you REALLY think Pennzoil would make that statement if you had to flush your engine every time you switched either way?

From a syn oil website:
How do I change to synthetic lubricants?
For a mechanically sound engine with less than 60,000 miles, and which has been well maintained (i.e. regular and frequent changes of dinosaur (petroleum) oil), you simply drain out the old and add the new synthetic lubricant with a fresh filter.
For vehicles with more than 60,000 miles or one with a questionable maintenance background, you may wish to clean the engine with an engine flush before installing the new synthetic motor oil. Without the engine flush a synthetic motor oil will use its inherit high detergency properties to clean a dirty engine resulting in a high volume of dirty oil being trapped in the oil filter. Furthermore, dirty oil has a tendency to burn more than clean oil resulting in an increase in oil consumption. If the newly installed synthetic motor oil becomes very dark (except for diesels) after only a few hundred miles, chances are the engine was still dirty upon changing to a synthetic motor oil and an engine flush and/or another oil change is warranted.

[ May 26, 2005, 10:31 PM: Message edited by: pscholte ]

 

[cortazzo]

I've read that when some people switch to syn after a history of using dino the first drain comes out very dirty and then starts to clean up after further drains. I'm about to switch my Jimmy to M1 this week, i'll probably run a short OCI just to be safe.

 

[Dick in Falls Church]

Within a few months after AMSOIL introduced their engine flush, complaints about excessive oil consumption during first change dropped dramatically.

Do you have to flush? Of course not. Should you flush? I do, with any car over about 25,000 miles. Just changing will clean things, too, but more slowly. If the engine is dirty, there is a chance that the oil filter will get pretty well filled up in the first couple thousand miles, and oil consumption may increase. If so, change the filter and top off.

Hving said that, when I picked up my 88 Saab 9000T it had 87K on it. Shop put in AMSOIL 10W-30 without a flush. Ran it a year (10K) with no problem, no oil added.

 

[Audi Junkie]

If you mean a running a quick fill of cheap oil before starting the synth, yes...it's recommended. I'd actually say use either supercheap oil for super-short or a 15w-40 for 2-4 weeks. The idea being that you can start with a slightly cleaner engine and not contaminate the new synth oil. Auto-Rx is a whole diferent story.

 

[gsnod]

What about running a synthetic blend for a few weeks or a thousand miles to do a little cleaning...

Will a blend start you on the way to use of a full synthetic?

 

[Audi Junkie]

To flush or not to flush, that is the question. It depends on the level contamination you are willing to tolerate. This all partly depends on how long your last oci was and how long you are inclined to drain your oil time-wise. An hour at home drains better than 30 seconds at a Quickie lube. Another factor is budget and value of the car. I'd be more inclined to flush a restored Porsche or Alfa than Grannie's Valiant.

Let's define "flush" better. A flush, to me, is just an intermediate oil to leave the engine internals clean...er for the top-quality oil that's intended for regular service, next fill. This practice makes sense and is recommended in some SAE manual and in the latest Mobil literature I saw where flushing was implied prior to use of the Mobil 1 EP.

Another time I do a quickie flush is after ARX cleaning with the same filter but before the formal Rinse Phase and new filter. This should drop out some gunk from ARX into the 1st filter and let me run a premium oil for "rinse" longer than the 1500 recommended miles.

 

[eljefino]

I'd do a quick OCI with cheap oil, not because you're going to synthetic, but simply because you don't know where this car's been. That's my SOP for any used vechicle I bring home.

I also use the manufacturer's recommended grade for that first change, just to get a baseline. If the prior owner loaded it up with 20w50, I want that out of there to see if I burn any.

I will literally bring out the drive-on ramps in the rain, at night, when I bring something home so I know for a fact what I've got in there.

If you have "dollar tree" stores pick up some trop-arctic 10w30 semi-syn for $1/qt for a quick rinse. Summer is also the perfect time for a run of 15w40 HDEO for cleaning (goes against my OE viscosity rule though.)

 

[Bror Jace]

I'm skeptical of 'flushing' if you mean adding any kind of serious flushing agent such as ATF, Seafoam, Gunk, Marvel Mystery Oil, etc ... before switching 'types' of oils.

I will add one or two ounces of MMO or 1 ounce of Neutra 131 to an entire crankcase for the last 100 miles before a drain if I feel the enigne could use a little extra cleaning ... but I don't go out of my way to recommend it to others.

For the sake of this thread, I'm leaving out Auto-RX as that is a serious, specialty product with its own regimen.

I think a short interval with a conventional oil is a pretty sound idea if you want to get the most out of a new synthetic. Gunk and/or acids left behind by previous neglect can take their toll on a synthetic's additive package and make going an extended time the first time a bad idea unless you know the engine was really well cared for.

But no, I don't think any kind of serious 'flush' is necessary before switching to synthetic.

--- Bror Jace

 

[Pablo]

I think a half quart of LC for a few hundred miles might be a good but subdued flush. No hard data, just a thought. Maybe go with a full quart if space and lack of worry permits.

 

[deuginthesky]

Do all green coloured engine cleaners are ester based ?