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Engine flush?

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Ned Kelly

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Anyone ever flush their engine to clean it out? I know you can get stuff like STP engine flush and others, but they are basically kerosene/diesel fuel. You can buy that at the gas station for alot less when it's not labelled as engine flush. See the bottom of this link for the main ingredient of engine flush:
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=16004096

and also for carb cleaner:
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=3007075

I have heard from mechanics that you can drain your crankcase, change oil filter, add 2 qts diesel, 3 qts cheap oil, run for 10 min at idle (no load), and drain. Repeat. Third time change filter and add 5qts oil and your engine is flushed.

What about using 30SAE (which is usually a high detergent oil) to clean out your engine? Run SAE30weight for a day or two and then change oil as normal? Any negative effects of running straight 30wt oil?
 
Not a good idea to try and flush your engine. What will happen is anything that you are able to break loose will end up clogging the hydraulic lifters or worse the oil pick-up screen. The sludge or build-up that might be inside your engine isn't harming a thing as long as it isn't floating around the engine or already clogging up the oil pick-up screen.
 
i have heard and done this trick.

5qt oil change but sub with 1 qt of atf and 4 qt oil. then drive 1k miles and redo. the oil comes out black ! . and it slowly loosens sludge so it will not plug up the stuff as fast if it was to try and do so.

but the best steps to a clean motor are good grade / brand oil and 3k mile changes.
 
Just pick up a can of seafoam and follow the directions. If that won't clean out your engine, nothing will.
 
seafoam or autoRX. Either will do the trick, slowly.

Dont go too fast, you'll clog up all those passages. The ATF trick does work, but its a little aggressive at times. You could also switch to a HDEO (diesel) oil, those have a lot more detergents than your regular oils.
 
speaking of oil:
What makes a good oil for an engine, what is a good weight? does more horse power mean you have to get a higher weight? hotter climate-thinner/colder climate-thicker?
i have a 454 (basically a mildly hopped up rv motor) with about 30k miles and am using 10-40 weight oil, i dont know why i use it other than, thats what my dad told me to use. i want to use full synthetic oil but it seems most of them are 10-30 and 20-50. would this increase/decrease engine performance, harm my engine? i never really spin over 4000rpm either if that makes any difference.
 
flush out the rings and bearings!..

I don't reccomend "flushing" a cranckase out that way,unless your sure the motor has had regular oil changes,and was never run with non-detergent motor oil..I've seen many old motors in older cars,tractors,etc,start smoking badly,or blow up shortly after "flushing" them..it loosens all the sludge and peices of stuff normally held captive in sludge,at the bottom of the oil pan,and can send it throughout the entire engine,where it acts as a grinding compund...

Many engines I have taken the oil pan off of,had peices of nylon timing gear teeth,broken valve stem seals,even the metal clips from a hydraulic lifter,peices of broken push rods,and the push rod seat where they sit in the lifters,all glued to the bottom of the pan by tarry sludge!--if not for the sludge,the motors would have likely been damaged or ruined,if they were free to float around the crankcase!..so a little sludge ain't always a bad thing!..

I have run 15W-40 diesel oil in gasoline engines with good results,but it does have a lot more detergent than your usual oil,and can loosen deposits as well..I've also added 1 qt. of Marvel Mystery Oil to the crankcase,that stuff seems to work well,but I can see where that could cause problems too,in an old sludged up motor..it's best to put a new (cheapie) oil filter on before flushing,if you must do so--then run the motor for several minutes at idle,and dump that filter,and put a new "good" brand one on when you change the oil..

My dad used to tell me it was a normal practice to flush engines out with kereosene before changing the oil in the 50's and 60's..the oil they had was nowhere near as good as todays,all they had was straight weight non detergent oils back then ,until they came out with multi-viscosity 10W-30 and 10W-40...

I usually only "flush" a motor that had anti-freeze get in the oil ,due to leaky head gaskets,and even then those motors usually start knocking soon after,if you let the coolant attack the bearings long enough..

Straight weight oil is no different than the multi weight as far as detergent,only difference is SAE 30 is 30W all the time,and will thicken into molasses at low temps..(there is still some non-detergent straight weight oil available,but it is not reccomended for anything newer than 1960 or so)..

I would run 15W-40 diesel rated oil in a motor known to be clean inside,it protects cam lobes better,and keeps the engine much cleaner..I'm talking full sized six or V8 motors,not V6's or 4 cylinder econobox motors--they need 5W-20 or 5W-30 in most cases..the wrong oil will damage them,many newer motors need THIN oil,and synthetic is reccomended in some....

I've read that 10W-40 is no longer recomended for many engines..something to do with the additives needed to make it cover such a wide range of viscosity breaking down ,and making sludge and varnish,and not lubricating well ...:crazy:
 
I was running 10 40 in my 427, but it has been soo cold this winter, I switched to 5-30 synthetic blend. It made a huge difference! I run a high volume oil pump, and with the heavy oil the truck was hard to start cold, and the oil pressure would jump up to around 80 psi. With the 5-30 synthetic blend, truck starts easier, and oil press is where it should be. also I found the oil (Phillips Trop-artic) for $ 1.60 per quart, pretty good for a synthectic blend, cheaper than the walmart brand recycled crap! I really like it and will probably use it again this summer, just switch to 10-30 or 10-40 blend Doug
 
stevos67k20 said:
hotter climate-thinner/colder climate-thicker?
Click to expand...

In that line of thought it's the other way around. Thinner for winter, thicker for summer.

If you have really good oil pressure with a lighter weight, I would cation against going too heavy, it could be too much and blow some seals.
 
Straight 30 and 40 are EXCEPTIONALLY common for marine apps, gas and diesel...
 
Glad to see someone agreeing with me. I've been building engines for 20 years professionally now and flushing an old engine is the worst thing that could be done.
 
4X4HIGH said:
Glad to see someone agreeing with me. I've been building engines for 20 years professionally now and flushing an old engine is the worst thing that could be done.
Click to expand...

Ok, I'll take this advice (and based on what others are saying here) as the vehicle I bought runs nicely and I don't want to risk killing the engine. I don't know it's maintenance history. My other vehicle has recieved relegious oil changes (synthetic) since the motor rebuild a decade ago, and is probably very clean inside.

Psychologically I'd like to flush the older engine to clean it out and then I'd FEEL it's clean..... but this may be more of a benefit inside MY MIND and not so good in practice. Everything is working fine, so I'll let it be. Thanks guys, you may have saved me from destroying a well running older engine if I flushed it.:doah:
 
4X4HIGH said:
Glad to see someone agreeing with me. I've been building engines for 20 years professionally now and flushing an old engine is the worst thing that could be done.
Click to expand...

Hey Scott, what do you think of people running this type of stuff through a motor to try and free a sticking lifter?
 
The old timer sticky lifter trick is to add 1 quart of ATF and run it. That will usually cure the problem without loosening up all kinds of crap in the engine.
 
txfiremank5 said:
In that line of thought it's the other way around. Thinner for winter, thicker for summer.

If you have really good oil pressure with a lighter weight, I would cation against going too heavy, it could be too much and blow some seals.
Click to expand...

i have a light duty high torque (low rpm) 454, with about 60 cold psi and about 40psi warm oil pressure at idle. am i using the right oil for my truck? its 10-40. if i go synthetic, what weight should i use for max performance? would a lighter/heavier weight be more beneficial?:thinking:

sorry to steal the thread but i think somebody else might also benefit from my question :doah: :dunno: ...maybe
 
10-30 synthetic should be good. It has much better properties than dino oil and protects well at very low and very high temps. I've been running synthetic in my 454 since 1989 and the engine is very clean inside and much easier to start in cold weather (compared to 10-30 dino oil).
 
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