Citirc Acid Cooling System Procedure

[catch2otwo]

So some of you may recall VWNate1's procedure where he uses a citric acid solution to clean/derust the cooling system. Mine was pretty bad so I decided to give it a try. I have a trip from SF to Montery coming up so I wanted to make sure it was nice and squeaky clean.

1st step - Flush out old stuff. I had it easy, my system was filled with water, no coolant. If you have coolant, please use a catch pan or something...

Pulled the plugs out of the block. These two plugs are located one on either side in the middle of the motor where the oil pan meets the block.



^^ You can see the water rushing out with plugs removed.

Here is what we are working with...




As you can see the rust is pretty crusty.

So next step is to flush it all out. Go get your garden hose, turn it on, and flush the radiator as well as the block. I put my garden hose on both top ports of the rad and also into the bottom side of the water pump. You should see water coming out of both ports on the block. I actually had to stick a pick into the driver side port to unclog it.

Button it all back up.

Degrease the inside... Nate recommended Shout detergent. Im not sure what the difference is between Shout and the other stuff, but thats what I used also. I used 1 cap full, about a 1/4 cup and filled the cooling system with straight tap water.

Ran it to and from work which is about 15 miles each way.
The idea is to get the system up to temp and let the solution circulate. The acid solution will not work if there is oil residue so this step is important.

Next step is drain the Shout solution. Essentially repeat everything until your water runs clear. The shout smells nice like fresh laundry!

Acid solution part! Nate suggested 1lb of citric acid powder to 3 gallons of water. I bought 5 lbs of citric acid powder off ebay. I used a food scale to roughly measure up 1 lb and then dumped 3 gallons of warm water into a 5 gallon bucket. Mixed it all up and in it went. keep mixing and filling until your system is full.

PRO TIPS:

1. Mix your powder and water in a bucket, dont pour the powder straight into the radiator. You want a good mixture before putting it in the system.

2. Mix up extra and keep it in a gallon jug to keep in your truck. Since you just drained your whole system, chances are you will have to top off. I just keep an eye on my over flow and have added some when it looked a little low.

Here is the inside of my rad after about 3 days. This is driving back and forth to work with a few side trips.



You can see there is quite a difference already. Nate mentions it really starts to work when the solution turns black. Mine is still pretty clear so I will check back in a couple days.

So far so good! Thanks nate for all your help.