Tricky coolant question, 1982 300D - PeachParts Mercedes-Benz Forum

300DPETE · #1 12-02-2005, 07:44 PM

1982 300D

A couple of weeks ago, I started a citric acid flush for my coolant system. When I was near the last flush of clean water to clear out the citric acid (last Friday), the car went out of commission.

So, it's been sittin with plain water since. Today, I drained it (both engine plug and radiator plug), and filled it up with 55/45 coolant before I had it towed to a machine shop.

Now, my question is, if the car didn't get a chance to circulate the 55/45 mix of coolant (by running the engine), is it possible that some parts of the coolant system will still have plain water in them, and will therefore freeze in the over the next 4 nights until I get the car towed back here? I'm concerned that any frozen water might cause a crack in the engine.

Am I worrying beyond all reason here?

Thanks,

Pete.

thorsen · #2 12-02-2005, 07:50 PM

Depends a lot on where you are. If you are in in Chicago where it is currently 19, I would say you have a case for concern. If the low temperature, I personally would not worry.

If you can still work on the car, I would remove the thermostat and the fan belts. Turn the water pump by hand to circulate the antifreeze.

300DPETE · #3 12-02-2005, 08:01 PM

I can't get to it, it's on a shop's property and they are closed for the weekend. It's supposed to get down to 26 overnight tonight...

300DPETE · #4 12-02-2005, 10:32 PM

Bump (it's getting cold out there).

Pete.

boneheaddoctor · #5 12-02-2005, 10:35 PM

I'm honestly not totaly sure where pure water might remain.....maybe it will have blended enough to not be an issue....since its all a moot issue right now as its out of your hands we can hope for the best...was it mixed beforehand or dumped in seperately? as in antifreeze and water seperately...if it was premixed I think you have the least worry...

300DPETE · #6 12-02-2005, 10:50 PM

I premixed it...I'm just wondering if if anything unmixed is behind the thermostat...

I also added the remainder (about 0.5 liters) into the top radiator hose.

Pete.

boneheaddoctor · #7 12-02-2005, 11:15 PM

Quote:

Originally Posted by 300DPETE

I premixed it...I'm just wondering if if anything unmixed is behind the thermostat...

I also added the remainder (about 0.5 liters) into the top radiator hose.

Pete.

it will probibly blend with pockets of pure water that may be in it.....forget the exact name for the process....I think you are about 90% safe with the temps we expect this weekend...

300DPETE · #8 12-02-2005, 11:23 PM

Quote:

Originally Posted by boneheaddoctor

it will probibly blend with pockets of pure water that may be in it.....forget the exact name for the process....I think you are about 90% safe with the temps we expect this weekend...

Okay, I'll only wory 10% of the time

t walgamuth · #9 12-03-2005, 12:00 AM

but it sounds to me as if you may have a problem. but that said benz blocks are pretty tough and there may be enough mixing to save you. if there is any way to get to it i would try to get the block heater turned on. with that going i would think you would be home free.

tom w

Elktonjohn · #10 12-03-2005, 12:12 AM

Pete, with your luck of late I'd normally be pessimistic and what with the wx going sour as it looks... well. From what I remember of college chemistry and ethylene glycol you should be just fine...even the other 10% of the time. Antifreeze just loves to mix with water and where they can meet the 2 volumes will seek...gosh fizzlin darnit what's the term...they will find a nice harmonious balance in chemically stable ,intermixed bliss. There is a perfect one word for that but I got a brain cramp. Help me out someone...grrr

Elktonjohn · #11 12-03-2005, 12:23 AM

Equalibrium!! Eureka! ...nevermind.

Ralph69220d · #12 12-03-2005, 09:38 AM

Every morning I stand in front of the mirror for one minute and practice saying, "I don't know". That said, any part of the coolant system will reach a complete mix of anti-freeze/water that is open to the point of where the water or anti-freeze(100%) was added, whether the anti-freeze and water or pre-mixed makes no difference. Problem areas such as the heater core, if the valves to the core were closed, then you have a problem in those areas. I think "diffusion" is the term other's knew, but couldn't get it to come to mind, but, then again, I don't know.

300DPETE · #13 12-03-2005, 09:47 AM

The heater core is the 5% I've been worying about (the other was "what's beyond the thermostat"). Does the heater core drain when you remove the engine drain plug (not just the radiator plug)?

Pete.

Ralph69220d · #14 12-03-2005, 10:36 AM

if the heater core is lower in height than the block drain, then it will not drain. If you can get to the shop's lot and open the heater valves, do so. I am ignorant as to whether your heater core valve(s) can be manually set, or whether it is controlled by vacuum systems and/or electronic control. Also, if the heater core return line is open to rest of block, the new coolant mix will diffuse and reach the heater core. If it is sunny during day the car's interior, if not shaded, will reach decent temps relative to outside. If it is cloudy at nights temp will drop less than a clear night. I hope the best outcome for you

#15 12-03-2005, 11:03 AM

The heater valve on his car is a mono valve that will be open when the car is turned off. I expect that the water in the heater core would have somewhat mixed and/or diffused with the 50/50 mix that was added. Remember, we don't need -50F protection at the moment. My best guess is that it will not freeze and cause damage. I don't believe a little "slush" in the system would hurt anything.