I am doing the dreaded citric acid flush this weekend (yay!).

Several of the steps needs coolant flowing through the heater core to fully flush the system. My CC system doesn't work very well. But, if I put the heat up and turn the blower on, some heat does come out of the vents.

Is this enough to verify that coolant is flowing through the core? Is there more testing/verification that I can do to be sure before the flush?

Oh and CC fix is next on the list. I dont want any green coolant in there over the winter :-)

Thanks!

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

If you disconnect the wire on the monovalve, the cabin should be so hot you can't stand it. If it's not, something is wrong somewhere.

Agreed. If the core is partially clogged, the citric acid flush should assist with that.

you could try turning the heat on after the vehicle has warmed up. if heat flows, you have coolant, if you get nothing, then it may be time to look a little further

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2003 Dodge Ram 2500 Cummins - Georend fully built trans, Banks Big Hoss Bundle, Smarty Tuner, 5" turbo back exhaust. 500 HP and 1100 ft/lbs to the ground.
1979 Mercedes-Benz 300CD - Lost to a four car pile up on 275, Thank You Michigan Drivers.
1986 Mercedes-Benz 300D - Sold, Euro non-turbo car.

and you will need more than a weekend to do a proper citric acid flush. you reallly need to drive around with the citric acid in there for at least 150 miles. several heatup cooldown cycles will help tremendously. like over a week of driving.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thanks Brian,tango. I'll pull the monovalve wire and hopefully roast.

Thanks vstech! I guess I should have said Ill be 'starting' the citric acid adventure Ill probably put it in this weekend, drive to work for a week, and then flush it and put in the right coolant the weekend after. That'll be 300 miles and 10 hot/cold cycles.

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car