use of engine cleaner BG Engine Purge

[JFP in PA]

Originally Posted by jakeru

My fairly new (to me) 2001 base with >100k on the clock recently got its first oil change. At only 7500 miles, which was half of the manufacturer recommended change interval, I was expecting it to look more clean than it did. But more alarmingly, I was quite surprised to find the newly changed oil, after simply idling the motor for a few minutes (to charge the oil filter), then letting it simply sit for several hours (to allow the oil level to stabilize, after which I drained about a pint to optimize the oil fill level) looks significantly darker than when it went in. That tells me there is residue in the motor.

I considered using a "flush" product, but I think the risk of unknown and potentially damaging chemicals lurking where you don't want them (e.g., in the lifters) is too great. I'll instead lower my oil change interval on the next change, and monitor the appearance of how carbon-loaded the drained oil appears. I might repeat that more than once if needed, New oil (some more than others - do you research to avoid this turning into an "oil holy war" thread) has detergent properties that should help clean residue from the motor, without needing to use any "additives" or "flush" products.

If you suspect build up, long before I would dump any aftermarket product into the engine, I would switch temporarily to a diesel oil such as the Shell Rotella T6, which is a 5W-40 0il that is both very high in detergency (required in a diesel) and in ZDDP (diesels do not have cats, so they can run high ZDDP).

When you change the oil after 3-5K miles, it will be ugly, but that is what you want.

[Gilles]

Originally Posted by JFP in PA

If you suspect build up, long before I would dump any aftermarket product into the engine, I would switch temporarily to a diesel oil such as the Shell Rotella T6, which is a 5W-40 0il that is both very high in detergency (required in a diesel) and in ZDDP (diesels do not have cats, so they can run high ZDDP).

When you change the oil after 3-5K miles, it will be ugly, but that is what you want.

JFP, a couple of years ago I bought a very low miles (but used) Volvo V70 non turbo for my wife to replace an identical one that was totaled by our youngest son (I am sure someone here can relate to this as well… ha)

The car was in pristine condition but the engine has some sludge build up that you can see when you put the oil on the engine and was considering flushing it, now the engine has about 80k and your idea of the Shell Rotella T6 sounds pretty good.

Question: Do you think that the high ZDDP content be fairly safe for the cat if used for 3-5k miles?

Thank you in advance for your comments!

[jakeru]

Thanks for the suggestion, JFP - I will take a look at running a synthetic 5W40 diesel oil for my next "engine cleaning" fill. From my experience with diesel engines, I recall their oil sure becomes dark (routinely completely black)!

By the way, pictured is what the 7500 mile old oil looked like (shown on a paper towel alongside new, uninstalled oil for comparison).

[Gilles]

Originally Posted by JFP in PA

If you suspect build up, long before I would dump any aftermarket product into the engine, I would switch temporarily to a diesel oil such as the Shell Rotella T6, which is a 5W-40 0il that is both very high in detergency (required in a diesel) and in ZDDP (diesels do not have cats, so they can run high ZDDP).

When you change the oil after 3-5K miles, it will be ugly, but that is what you want.

JFP,

Sometimes, I get a noisy lifter when the engine is warming up, do you think that switching (temporarily) to the Shell Rotella T6 somehow could help to clean the lifters?

My engine has a bit over 100k and other than the occasional lifter noise, it runs pretty smooth (Been changing the oil @ +/- 5k miles since new)

As always, thank you for our comments.

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