Flushing Engine with Citric Acid

[Klink]

Mercedes Benz flushes it's aluminum radiators and engines with citric acid. I believe they remove thermostat and pour 12% citric acid granules which is first dissolved into sufficient water to fill the radiator. The engine is run for x minutes, and then flushed out with fresh water. I can provide more details later.

I've used the mixture before to clean rusted metals parts, and it leaves them clean and smooth (not rough like muriatic acid). I used it to flush out an old Perkins diesel that was really rusted bad.

Now, I wondering if this system can't be used in my 1990 Johnson 115 to clean the passages? Putting the mixture in a barrel and letting the engine run in it for whatever time.

Any thoughts?​

 

[Klink]

Re: Flushing Engine with Citric Acid

Mercedes Benz flushes it's aluminum radiators and engines with citric acid. I believe they remove thermostat and pour 12% citric acid granules which is first dissolved into sufficient water to fill the radiator. The engine is run for x minutes, and then flushed out with fresh water. I can provide more details later.

I've used the mixture before to clean rusted metals parts, and it leaves them clean and smooth (not rough like muriatic acid). I used it to flush out an old Perkins diesel that was really rusted bad.

​

More details:

 

[Klink]

Re: Flushing Engine with Citric Acid

I'm talking about food grade citric acid, it is not a strong acid like muriatic. You can eat it, it tastes like sour balls.

 

[colbyt]

Re: Flushing Engine with Citric Acid

It is an interesting concept. 13 ounces to the gallon should not be all that strong. The flushing would be real important.

 

[emckelvy]

Re: Flushing Engine with Citric Acid

Add a little grape flavoring and I bet it makes a mean Bug Juice!

It should do a good job of cleaning; I still remember seeing sailors soak firemain valves & parts in Bug Juice on the aircraft carrier, when I worked in the naval shipyard.

Cheers..........ed

 

[Klink]

Re: Flushing Engine with Citric Acid

It will work very well on inboard engines with heat exchangers (diesel and gas) and such, as they are just like automotive engines. However, a 2 cycle engine like mine (1990 Johnson 115 V4 Crossflow) is very dirty, there's fuel and oil in the exhaust due to scavenging. If you notice in my instructions, the engine must first be cleaned with dishwashing machine soap (it makes no suds) to get rid of the oil in the engine. The oil in the engine neutralizes the cleaning effect of the citric acid. For that reason, thinking it over, it just wont work on an older 2 stroke.