http://www.amazon.com/Gunk-High-Mileage ... B000AME4V4

Do any of you guys have first hand experience with this product or reviews on it?

Since we're on this topic, I've heard a lot of Marvel Mystery Oil but no experience with it either. http://www.amazon.com/Gunk-High-Mileage ... B000AME4V4

^Marvel mystery oil is actually some really good stuff. It loosens carbon build-up REALLY well, but it has to soak, it isn't just some run through and it is instantly clean thing.

i wouldnt use MMO if you have any oil leaks. I had been running regular oil for a couple years with a leaking distributor, but within a couple weeks of putting in MMO it caught fire, oil got down to the alternator (supercharged engine) and it started there, and also took out the dizzy electronics, some wires, the cap and the rotor with it. luckily the whole thing didnt burn up and i was able to fix it easily. I then learned that the MMO has a MUCH lower flash point than regular oil about 150* instead of 450* or more for regular oil (they say you can use MMO in the gas as well which is probably why). It is also very thin compared to most oil and i noticed it seemed to burn more oil when using MMO (the oil level would drop quicker, i noticed this on another car that wasn't leaking oil as well).

harobikr444 wrote:i wouldnt use MMO if you have any oil leaks. I had been running regular oil for a couple years with a leaking distributor, but within a couple weeks of putting in MMO it caught fire, oil got down to the alternator (supercharged engine) and it started there, and also took out the dizzy electronics, some wires, the cap and the rotor with it. luckily the whole thing didnt burn up and i was able to fix it easily. I then learned that the MMO has a MUCH lower flash point than regular oil about 150* instead of 450* or more for regular oil (they say you can use MMO in the gas as well which is probably why). It is also very thin compared to most oil and i noticed it seemed to burn more oil when using MMO (the oil level would drop quicker, i noticed this on another car that wasn't leaking oil as well).

...444 FTW!

ogdougynutty wrote:^Marvel mystery oil is actually some really good stuff. It loosens carbon build-up REALLY well, but it has to soak, it isn't just some run through and it is instantly clean thing.

Carbon buildup where? In your oil?

If you are looking to clean up the system it's hard to beat BG products.
http://www.bgprod.com/

For the most part these products are still rarely needed or particularly beneficial. The occasional injector cleaner (like once a year) isn't a horrible idea but if you are running decent gas shouldn't be needed.
I like running a bottle of iso-heat through the tank once a year just in case any water has collected.

If you change your oil regularly then internal buildups shouldn't be an issue and solvents like the ones posted here can actually knock oil loose that is sealing old seals and it can even knock larger bits loose that could clog fine oil passages.

Most of the claims by products like MMO are complete BS such as

By creating a top ring seal, it produced higher compression and, by preventing blow-by on power strokes, it resulted in more power. Mystery Oil also improved gas mileage and minimized engine wear.

So although it could have beneficial uses in a very limited capacity it's probably about 1% of what they claim.

yoshimitsuspeed wrote:

ogdougynutty wrote:^Marvel mystery oil is actually some really good stuff. It loosens carbon build-up REALLY well, but it has to soak, it isn't just some run through and it is instantly clean thing.

Carbon buildup where? In your oil? /quote]

No, like places where carbon builds up i.e. pistons and exhaust valves. Mistakenly found that out when i did a head gasket, when i sent the head out to get skimmed it took a little while to get it done. So i put a little bit of MMO in the cylinders to keep them from getting dry. Put everything back together ran the car and about a week later I did a normal tune-up and when i pulled the plugs, the top of the pistons were clean as clean could be.