Engine cleaner

[otis24]

I bought an older GMC pickup from a friend. Got it really cheap. Wouldn't start, may have a bad fuel pump. He had let another guy borrow the truck. That guy ran it a little low on oil. My friend thinks it may have a stuck valve. I bought the truck just to see if I could get it running and then sell it.
Another friend, a mechanic, suggested changing the oil and adding a quart of transmission fluid in exchange for one quart of oil. I had planned to add a quart of Marvel Mystery Oil. Which one will clean the engine better and faster?
I also plan to run a quart of transmission fluid through the carb just in case the valve's are sticking. Thanks for any help you can give!

 

[bkrell]

Most people don't really recommend transmission fluid. There are several types of cleaners and solvents that you can add. AutoRx is very popular on hear for a slow thorough cleaner. I myself like Berryman Chemtool B-12. Other folks don't b/c they think it too harsh. Never bothered me though. Anyway,read through the threads and check out the additives forum. This is a well worn topic.

 

[otis24]

I am currently using Auto-Rx in my Ford F150. I am looking for something quick and effective. I just plan on getting the Jimmy running and then selling it. Gurss I'll try the Marvel Mystery Oil (once the 10 inches of snow we are supposed to be getting melts).

 

[Fastride95]

MMO, Rislone, CD-2 Max, Seafoam, B-12 or any of the OTC engine flushes if you're just trying to clear some immediate problem and get it started.

ATF may work. Everyone is hung up on it's lack of detergents but I'm betting it works due to the solvent properties of the lightweight oil. I know the MMO will work well for unsticking valves and burns off fairly clean.

Personally, I'd pickup 2 oil changes worth of the flushing agent (follow directions) and a cheap light conventional oil like Supertech 5w-20 and just do them back to back. I'm assuming you'll use a flush that works with the engine idling (not under load) when I recommend such a light motor oil mixed with an even lighter flushing agent.

Use a higher viscocity oil you like + 1 qt of MMO for the 3rd and final change to run that out a few hundred miles or even to just leave it in there to sell it. Throw a qt of MMO, a canister of B-12 or bottle of Techron concentrate and a couple bottles of Heet in the fuel tank with 10 gallons of gas and run it around.