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Cooling System Flush
The over the counter cleaners available at any FLAPS generally have fallen short (IMHO) in their ability to safely remove scale and deposits from an engine's coolong system. I have used various brands over the years with poor results at best and many dollars wasted in the effort to keep cooling systems working well.
Having owned vehicles with aluminum radiators, heads and blocks and borrowing from our friends at Mercedes Benz I have come up with a safe and expeditious cleaning regimen. The techniques is suspiciously easy and I have found in limited testing (6 vehicles) that it will not damage the metallic components on an engine.
Again, Mercedes Benz cleaners use the same ingredient, I find buying off the web in bulk to be much lower cost.
materials needed:
10-15 gallons distilled water
3-5 lbs citric acid, use food grade citric acid.
Steps:
Engine cold
1. Open heater control valve to max temp, remove lower radiator hose and heater core line, drain old coolant into container and discard.
2. Reinstall hoses and refill with distilled water. (if your engine has a specific air bleed requirement perform it per the manufacturer)
3. Operate the engine for 3-5 minutes at high idle.
4. Let cool at least 10 minutes then drain coolant. Do no be impatient, if you dump the coolant too soon you can warp components due to heat soak effects.
5.Using a plastic container mix citric acid with water to form a thick soup.
Pour the "soup" into the radiator filler. On a badly scaled system go heavier on the citric acid.
6. Refill the unit with distilled water. Bleed air as before, operate engine to purge air properly (again per mfgs directions) then let the engine fast idle for 45-90 minutes. If you have a tachometer 1500 RPM is OK. Keep an eye on the temp gauge to make sure that your unit does not over heat during this procedure. On a badly scaled 4 cylinder engine I've found the process takes a little over an 45 minutes. The indicator I used was the temperature gauge falling (engine getting cooler) as the radiator efficiency increased.
7. Drain, refill with distilled water, purge air and operate the system as described under items 2, 3 and 4 at least three times minimum. Unless you have very soft water resist the temptation to use a garden hose for this step.
8. Refill with the correct mixture of your anti-freeze of choice making sure to purge air as required. Operate the engine for a few minutes to check for leaks.
9. Take a last look to make sure that lines and connections are tight and all tools accounted for before you close the hood.
In my opinion if you are converting from Dex-cool to another type of anti-freeze this technique removes desposits very well and presents the best possible set of conditions for a successful switch over.
This technique has worked well for me, it is up to you to determine if the procedure can be safely carried out on your vehicles' cooling system. I cannot be held responsible if your system develops leaks. I have found that some pinholes developed on the radiator in one of my vehicles that the earlier scale masked.
Good Luck
Andromeda
99 Lumina LS 3100
Having owned vehicles with aluminum radiators, heads and blocks and borrowing from our friends at Mercedes Benz I have come up with a safe and expeditious cleaning regimen. The techniques is suspiciously easy and I have found in limited testing (6 vehicles) that it will not damage the metallic components on an engine.
Again, Mercedes Benz cleaners use the same ingredient, I find buying off the web in bulk to be much lower cost.
materials needed:
10-15 gallons distilled water
3-5 lbs citric acid, use food grade citric acid.
Steps:
Engine cold
1. Open heater control valve to max temp, remove lower radiator hose and heater core line, drain old coolant into container and discard.
2. Reinstall hoses and refill with distilled water. (if your engine has a specific air bleed requirement perform it per the manufacturer)
3. Operate the engine for 3-5 minutes at high idle.
4. Let cool at least 10 minutes then drain coolant. Do no be impatient, if you dump the coolant too soon you can warp components due to heat soak effects.
5.Using a plastic container mix citric acid with water to form a thick soup.
Pour the "soup" into the radiator filler. On a badly scaled system go heavier on the citric acid.
6. Refill the unit with distilled water. Bleed air as before, operate engine to purge air properly (again per mfgs directions) then let the engine fast idle for 45-90 minutes. If you have a tachometer 1500 RPM is OK. Keep an eye on the temp gauge to make sure that your unit does not over heat during this procedure. On a badly scaled 4 cylinder engine I've found the process takes a little over an 45 minutes. The indicator I used was the temperature gauge falling (engine getting cooler) as the radiator efficiency increased.
7. Drain, refill with distilled water, purge air and operate the system as described under items 2, 3 and 4 at least three times minimum. Unless you have very soft water resist the temptation to use a garden hose for this step.
8. Refill with the correct mixture of your anti-freeze of choice making sure to purge air as required. Operate the engine for a few minutes to check for leaks.
9. Take a last look to make sure that lines and connections are tight and all tools accounted for before you close the hood.
In my opinion if you are converting from Dex-cool to another type of anti-freeze this technique removes desposits very well and presents the best possible set of conditions for a successful switch over.
This technique has worked well for me, it is up to you to determine if the procedure can be safely carried out on your vehicles' cooling system. I cannot be held responsible if your system develops leaks. I have found that some pinholes developed on the radiator in one of my vehicles that the earlier scale masked.
Good Luck
Andromeda
99 Lumina LS 3100
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