Cleaning inside the engine

[santonio03]

Im getting my oil changed next week and before i do that what can i add my my oil that can cleaning my engine inside( like lifters and stuff). A mechanic told me to just add marvel mystery oil to my oil. is their anything better?

[gonzo4191]

you can add sea-foam to the engine oil even. But its usually better to run it through the intake hose!

good luck

[LeSabre in Buffalo]

Your mechanic is right. Marvel Mystery Oil is a very effective cleaner. Run the MMO for 1000-1500 miles before you change the oil. Then watch how much gunk comes out. Cut open the filter for a truly gnarly sight.

MMO cleans out stuff gently and suspends it in the oil. If any larger stuff gets cleaned, it'll be caught in the filter. Don't worry, this is what the oil and filter are meant to do.

Or, since you're changing oil next week, substitute a quart of MMO for a quart of oil, then change the oil at 2000 miles. Change the next oil change at 3000 miles, and then go back to your regular schedule.

If you want to really clean it out, use a 15w-40 oil like Rotella T5 with the MMO. IF you do that, change the filter at 1000 miles and top off with more Rotella. No sense in grenading your engine from lack of oil pressure caused by a plugged filter.

Also look at Auto-RX. I've used Auto-RX before, and it's good stuff. So is MMO.

[willwren]

I've seen the internals of more 3800 motors than most members here, and I've yet to see one that wasn't clean inside. I've never seen one that had sludge, and the only gunk was caused by coolant in the oil from an upper intake failure.

Save your money. Just do regular oil changes with quality oil, and your engine internals will stay clean.

[myfirstbonnie]

[renchjeep]

I have seen a few cases (not 3800's specifically) where people have used some type of "oil flush" or "internal engine cleaner" before an oil change on a high-mileage engine, and it cleaned out all the gunky crap alright, leaving low oil pressure and rod knocks behind!

Maybe the "new" engine cleaners are better?

Oil and filter changes every 3,000 miles for conventional oil (5,000 for synthetics) have always been my procedure. Be sure to check your oil level at each fill-up of gas, or at least every second fill-up. Your engine will thank you.

Modern "standard" oils are WAY better than they were just a few years ago. Synthetics are a step up on conventional oil, but I have heard bad things about changing from conventional to synthetic on mid- to high-mileage engines.

Everyone please feel free to confirm/deny, or add to my observations.

[willwren]

Somewhat pointless considering the original poster is banned, but most of those motors you've seen/heard about were probably loose-tolerance motors with very high miles, where the gunk was holding things together.

3800's don't have this problem. They're a performance oriented motor from the factory with very tight tolerances. It takes years of abuse to build up any gunk. So you can't HURT them by doing this, but you can't help them either.

Save your money for gas. Prices are going up.