[wlake73]

is a can of motor flush advisable prior to oil change? 2007 sx21 merc v6

[Oregondunes]

how old, black and grungy is your motor oil ?

the only time you need something like that is in a motor that hasnt had an oil change in like 5 years. If you think you wanna flush the engine, drop in a gallon of diesel before you change it. let the engine IDLE til warm, then drain.

After refilling the oil, startup and let idle til warm again, then change the filter only one more time and your ready. Dont forget to check the level and add after the last filter change.

[wlake73]

thanks, oil is one season and clean. but hi revving boats i thought may need more care. 09 was first change since new in 07 after 20 hours and it was black but flowed smoothly.

[Oregondunes]

Don't get sucked into snake oil gimmicks. Sure if you got a boat that after 5 years and had never been serviced and the oil looked like fudge, then I'd say YEAH use something. But dumping a couple quarts of diesel in her and letting her warm up in the driveway before you drain her wouldn't hurt. I'd stil swap filter after a change and a warm up tho.

[Dredd]

What does the diesel do to help "flush" the oil?

[Oregondunes]

Dilutes or thins the oils and any deposits. If there is any build ups they will flush out. Though by diluting the oils they don't offer much protection. Don't rev the motor. Let idle only.

[Dredd]

Hrm, makes sense I just hadn't heard of it before. Sounds scary though.

[Oregondunes]

Old skool