Engine Flush Debate
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Take a look at these photos.
First one engine at 70K, previous owner most likely did some oil changes on schedule, but maybe went beyond the 7500 mile book value. "Golden" crust.
Next one, you like your catch of the day blackened? Higer miles, infrequent oil change, typical "I can't afford it" service posture.
Next one, non-Rover, but certainly super sludge delight. High miles between changes.
Next, Rover that had oil changed at 3,000 mile intervals, Castrol, then switched to Rotella. About 180K miles.
Last, interior with "varnish".
Now if you have one of the four delightful engines, some solvent on a rag or Q-tip and rub it on the dried gunk you can see thru the oil fill cap. If the dried stuff comes right off to clean metal, maybe that solvent will do some good. If all you get is a little color, it wil take solvent a long time to produce results. If the stuff is already baked on, it is there to stay. If you can wipe it off with your finger, the cleaning agents in Rotella will get it over time. Rotella, and other top quality diesel oils, are formulated not only to clean, but also to hold that stuff in suspension (soot management), so it does not just sink to bottom of oil pan. In suspension, the filter will trap it.
If you add a solvent (kerosene, naptha, mineral spirits, ATF) you reduce the viscosity of the existing oil. It may get into a small place that regular oil is having a problem reaching. However, with reduced viscosity you have increased wear. Sorta like using 200 grit sandpaper to whiten your teeth. You also have the distinct possibility that large enough gunk will come loose and clog oil pick up screen, and/or oil filter and other places.
You might free up a sticky lifter, but you should not consider the use of a solvent flush as the cure for what ails you. And it can't make up for 200,000 miles of running hot with 10W30 oil changed every 35,000 whether it needed it or not.
A brief use of solvent may produce some darkened oil that drains. But running around with 5 quarts of ATF in the engine for a week is not a good plan.
First one engine at 70K, previous owner most likely did some oil changes on schedule, but maybe went beyond the 7500 mile book value. "Golden" crust.
Next one, you like your catch of the day blackened? Higer miles, infrequent oil change, typical "I can't afford it" service posture.
Next one, non-Rover, but certainly super sludge delight. High miles between changes.
Next, Rover that had oil changed at 3,000 mile intervals, Castrol, then switched to Rotella. About 180K miles.
Last, interior with "varnish".
Now if you have one of the four delightful engines, some solvent on a rag or Q-tip and rub it on the dried gunk you can see thru the oil fill cap. If the dried stuff comes right off to clean metal, maybe that solvent will do some good. If all you get is a little color, it wil take solvent a long time to produce results. If the stuff is already baked on, it is there to stay. If you can wipe it off with your finger, the cleaning agents in Rotella will get it over time. Rotella, and other top quality diesel oils, are formulated not only to clean, but also to hold that stuff in suspension (soot management), so it does not just sink to bottom of oil pan. In suspension, the filter will trap it.
If you add a solvent (kerosene, naptha, mineral spirits, ATF) you reduce the viscosity of the existing oil. It may get into a small place that regular oil is having a problem reaching. However, with reduced viscosity you have increased wear. Sorta like using 200 grit sandpaper to whiten your teeth. You also have the distinct possibility that large enough gunk will come loose and clog oil pick up screen, and/or oil filter and other places.
You might free up a sticky lifter, but you should not consider the use of a solvent flush as the cure for what ails you. And it can't make up for 200,000 miles of running hot with 10W30 oil changed every 35,000 whether it needed it or not.
A brief use of solvent may produce some darkened oil that drains. But running around with 5 quarts of ATF in the engine for a week is not a good plan.
Last edited by Savannah Buzz; 06-01-2012 at 08:21 PM.
#10
Join Date: Apr 2006
Location: Denver, Colorado
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If the engine is a little sludged up internally, why not, put in a can of Gunk or any other engine flush, follow the directions and then change your oil.
I do this once a year to stay ahead of an engine issue and I feel it is a benefit to do it, if you don't want to that is your call, I have had 100's of people do it, haven't blown up an engine yet and most are quite pleased at how much quieter the engine runs.
I do this once a year to stay ahead of an engine issue and I feel it is a benefit to do it, if you don't want to that is your call, I have had 100's of people do it, haven't blown up an engine yet and most are quite pleased at how much quieter the engine runs.