[k0rupt3d]

I Just picked up a 289 motor it is extremely dirty iv flushed water through the thermostat housing 10 times and still the water is dark redish brown. I don’t want to tear down the motor to flush the water jackets. Anyone have an idea how to clean it out?

[phillystangman]

run simple green through the engine and flush several times simple green is non corrosive and doesnt sud to bad used it on a 302 block and worked great

[andrewmp6]

If its that nasty your better off stripping it.

[Ivy66GT]

Andrew might be right about stripping the engine. But if that isn't in your plans then a detergent flush is a first start to get rid of the grease and oil. Nearly any detergent that doesn't make a lot of suds will work; I used dry dishwasher detergent first dissolved in heated water. Sodium metasilicate pentahydrate is the REAL thing to use but its harder to find: its called Red Devil TSP-90 available in the paint department of some hardware stores, its their phosphate free TSP.

After you have flushed out all the detergent you can run citric acid though it which will clean out rust but is mild enough that it doesn't affect much of anything else. Its the Mercedes specified way to clean a cooling system. For a 289 I use 2 pounds of powdered citric acid for a complete radiator/block flush again dissolved in water before putting it in the radiator. Even if the water looked clean before the citric acid will bring out a lot of crud. Several places sell citric acid for $15-20 for a 5 pound bag. Google it. The edible 'food grade' acid will work but its not required unless you want to drink the radiator water.

[k0rupt3d]

cool thanks alot guys im gona try that this weekend

[k0rupt3d]

Originally Posted by Ivy66GT

Andrew might be right about stripping the engine. But if that isn't in your plans then a detergent flush is a first start to get rid of the grease and oil. Nearly any detergent that doesn't make a lot of suds will work; I used dry dishwasher detergent first dissolved in heated water. Sodium metasilicate pentahydrate is the REAL thing to use but its harder to find: its called Red Devil TSP-90 available in the paint department of some hardware stores, its their phosphate free TSP.

After you have flushed out all the detergent you can run citric acid though it which will clean out rust but is mild enough that it doesn't affect much of anything else. Its the Mercedes specified way to clean a cooling system. For a 289 I use 2 pounds of powdered citric acid for a complete radiator/block flush again dissolved in water before putting it in the radiator. Even if the water looked clean before the citric acid will bring out a lot of crud. Several places sell citric acid for $15-20 for a 5 pound bag. Google it. The edible 'food grade' acid will work but its not required unless you want to drink the radiator water.

I was just thinking about the process last night and was wondering do I just take the thermo off and pour the detergent right in then after a few flushes pour a scoop of it in?

[Ivy66GT]

I left the thermostat in place. Especially the citric acid works better the warmer it gets so you need the thermostat to get the coolant temp up to where the acid will do a good job.

I heated the detergent and a gallon of water in a pan on top the kitchen stove to make sure it was dissolved. Then drained the radiator and block, poured the detergent solution in the radiator, filled it up the rest of the way with water and started the engine. This may trap an air bubble so after it ran a bit I shut it down and refilled the radiator. Ran it on high idle for several minutes after the thermo opened then shut it down, drained and did repeated flush cycles of water until the drain water looked clean.

Once I had done it with the detergent, I repeated the whole process again using citric acid.