I have seen similar issues with the over zealous use of the old Bars-Leak rhizex pellets, green coolant and a water wetter agent. This was also done at a garage, the mechanic thought bas leak to cure or prevent any leak and water wetter to improve the coolant performance, in the end it was a horrible friggin mess.
The procedure to get it clean was pretty involved but easy enough.
Replace the hoses (radiator and heater) and thermostat but make use of the old ones first by installing a flushing T in the old heater hose.
1) Install T and remove the thermostat, reinstall the housing sans thermostat and flush as much of the junk as possible out while letting the engine idle.
2) Empty the system and refill with a box of cascade dissolved in warm tap water, run the engine for 30 minutes, let sit an hour and flush it out.
3) Refill with a couple of gallons of cheap vinegar, let it warm at idle, let sit for 10 min and flush.
4) Mix a box and baking soda with warm tap water and refill, run the engine at idle for 10 min and flush it thoroughly, remove heater hoses and reverse flush the heater core.
5) Refill with tap water and leak test the system, if its all tight and no leaks drain and replace all the hoses and refill the system with 50/50 with the thermostat out and housing removed. When the coolant reaches the thermostat base, install it and the housing and continue refilling. start the engine and bleed as usual.
This should get the system clean and allow good coolant flow and heat. Cascade is OE recommended by a major diesel engine manufacturer for cooling system cleaning, the vinegar is mostly water with a small percent of acid, it cleans aluminum well without much risk if flushed out and neutralized after a short time.
Edit: Use tap water and garden hose for flushing, distilled for final 50/50 fill, no point in flushing $1 a gallon stuff away for flushing.
The procedure to get it clean was pretty involved but easy enough.
Replace the hoses (radiator and heater) and thermostat but make use of the old ones first by installing a flushing T in the old heater hose.
1) Install T and remove the thermostat, reinstall the housing sans thermostat and flush as much of the junk as possible out while letting the engine idle.
2) Empty the system and refill with a box of cascade dissolved in warm tap water, run the engine for 30 minutes, let sit an hour and flush it out.
3) Refill with a couple of gallons of cheap vinegar, let it warm at idle, let sit for 10 min and flush.
4) Mix a box and baking soda with warm tap water and refill, run the engine at idle for 10 min and flush it thoroughly, remove heater hoses and reverse flush the heater core.
5) Refill with tap water and leak test the system, if its all tight and no leaks drain and replace all the hoses and refill the system with 50/50 with the thermostat out and housing removed. When the coolant reaches the thermostat base, install it and the housing and continue refilling. start the engine and bleed as usual.
This should get the system clean and allow good coolant flow and heat. Cascade is OE recommended by a major diesel engine manufacturer for cooling system cleaning, the vinegar is mostly water with a small percent of acid, it cleans aluminum well without much risk if flushed out and neutralized after a short time.
Edit: Use tap water and garden hose for flushing, distilled for final 50/50 fill, no point in flushing $1 a gallon stuff away for flushing.
Last edited:
