Topic: Question regarding coolant drain/fill

[curls]

I decided to spend some time yesterday draining and refilling the coolant in my wifes' Protege5, since it was a little overdue.  I checked the Mazda Service manual and it said the drain/refill capacity was 6.x Litres (I think 6.7L, 7.0L on a dry block and radiator).  So I went and bought 2 x 3.87L jugs of premixed coolant and got to work.

Drain completely, including the resevoir.
Refill with water, start engine, get to operating temperature, then stop engine and drain again.
Ensure the 'water' coming out this time is nearly or completely clear.  Check.
Now, it said to add the premixed coolant at a rate of 1L per minute, which I guess gives the air bubbles to get out of the system.  So, I took 5 minutes to add one jug of coolant (3.8L).  Great.  BUT, the only problem is, the rad was COMPLETELY full by the end of this.  I even had enough leftover to top off the resevoir as well.

Then the instructions said to start the engine w/ rad cap off, and let it get to operating temperature.  I did that, and the rad burped twice (air bubbles escaping), and the rad fan came on a few times.  But even then, I still didn't have to open the 2nd jug of premixed coolant in order to top off the radiator.

Any idea why I can only get in about 4L of coolant when the manual says it takes much more than that?  Did I do something wrong?  Or was there just extra coolant in the block that wouldn't make its way out of the system without removing some hoses, and that's what occupied the extra space?

Thanks.

[tortoise]

Now, I'm no expert.  Was the heater setting set to hot?  Could the extra coolant be caught in the heater core?

[curls]

When I was running the car after the fill, I turned heat to COLD and fan off, so the system was essentially turned off.  I'll try parking backwards in the garage tomorrow with her car -- there is a slight incline that made the radiator slightly higher with respect to the engine, than normal.  Maybe it was trapped in the heater core or elsewhere because of the very slight incline?

Or maybe I will do it all over again next weekend with new coolant entirely, and ensure that the rear of the car is on jackstands to make it level with the front...

Or, is 2/3 of a replacement going to be OK for the car, and I can just leave it as-is until 48,000km from now when the next scheduled replacment is due?

[articsteve]

 Or was there just extra coolant in the block that wouldn't make its way out of the system without removing some hoses, and that's what occupied the extra space?

I take it that you drained the system via the rad drain . 

In almost all engine blocks there is a drain plug.  Usually very hard to access and always really super tight.  So tight the only way to loosen is to be STANDING under the vehicle with a breaker bar.  These plug are usually about 17mm.

The lower part of the block retains quite a bit of volume.  As mentioned, the heater core retains a bit as well.

Me thinks you're too diluted since you ran water through the system first.  I'd measure the level of glycol with one of those gauges with the ball and needle just to be sure you are at -35C. 

Also, if you used the rad drain   then the hoses would have drained completely.

[curls]

Or was there just extra coolant in the block that wouldn't make its way out of the system without removing some hoses, and that's what occupied the extra space?

I take it that you drained the system via the rad drain . 

In almost all engine blocks there is a drain plug.  Usually very hard to access and always really super tight.  So tight the only way to loosen is to be STANDING under the vehicle with a breaker bar.  These plug are usually about 17mm.

The lower part of the block retains quite a bit of volume.  As mentioned, the heater core retains a bit as well.

Me thinks you're too diluted since you ran water through the system first.  I'd measure the level of glycol with one of those gauges with the ball and needle just to be sure you are at -35C. 

Also, if you used the rad drain   then the hoses would have drained completely.

Hey arctic...

I followed the service manual AND the owners' manual, down to the letter.  Neither mention a block drain plug at all.  Also, 95% of the online tutorials I've been glancing over, never even mention this block drain plug.

I simply used the radiator drainplug and that's it.  Maybe the slight change in angle, being parked on an incline, trapped a bunch of coolant in the block and heater core.

I doubt I'm too diluted, since I didn't force water in with a hose - I filled it the exact same way as you would with coolant (from a few 2L bottles of Coke).  And, it came out very, very clear... the same way as it went in.  The original coolant I drained was yellowish.  The new coolant (store-brand, not OEM) was neon green.  If/when I check the rad today after my wife gets homef rom driving aroudn all day, I'll note the colour.  If its anything other than the green I saw yesterday when it went in, I'll investigate this block-drain thing further.

[safristi]

wots wrong with the old hose in the RAD fer a 10 minute FLUSH then refill.....fack it ain't Rrocket science!!!

[curls]

wots wrong with the old hose in the RAD fer a 10 minute FLUSH then refill.....fack it ain't Rrocket science!!!

This is Canada.  Having an outdoor garden hose turned on in the winter is a bad idea.

[articsteve]

I doubt I'm too diluted, since I didn't force water in with a hose - I filled it the exact same way as you would with coolant (from a few 2L bottles of Coke).  And, it came out very, very clear... the same way as it went in.

I might be misunderstanding your procedure, but when you said you flushed the cooling system out with water, I assumed you refilled with water and then ran the motor for a few minutes with the heater control turned to high and then dumped that out.  That's how you flush all the acidic waste antifreeze out of the entire system including heater core.  Then you get the rest out of the block by removing the drain plug from the block if you can find it and get to it.

Found this on a goooooogle search.

Where is the coolant drain plug in a 97 Mazda Protege? 
   

Answer
There is usually one on the bottom of the radiator.


Possible Answer
I have gone to the dealer and the chief mechanic said that there is no drain plug on the 1997 mazda protege. Sounds sketchy to me, but I can't find it either.


***Many (most I think) cars have two drains in the cooling system -- one on the bottom of the radiator and one on the engine block. You normally open both when changing the coolant because the coolant won't drain out of the block very well if you don't. I expect that the dealer and chief mechanic were answering the question "Where is engine block coolant drain plug?" I have just been crawling around under my 2002 Protege which I think has much the same engine as the 1997. Damned if I can find a drain plug on the block. Based on what you were told, I'm going to proceed on the assumption that there isn't one*** vtcodger

[safristi]

hot water out tha kitchen too difficult.....yeah in Mid Wintaa that's wot I woz tinkin why not pay $48 fer a Rad special at Midas or Wally Smart?

[PJungnitsch]

The easiest way is to refill with straight undiluted coolant, as mentioned. Pour in the proper amount (as per whatever blend you want with the stated capacity), then top up with distilled water.

Then fill the overflow with the proper mix.

As you've noticed when you refill a flushed system with premix you tend to not get enough glycol in the system, especially if you can't drain the block.

[curls]

I doubt I'm too diluted, since I didn't force water in with a hose - I filled it the exact same way as you would with coolant (from a few 2L bottles of Coke).  And, it came out very, very clear... the same way as it went in.

I might be misunderstanding your procedure, but when you said you flushed the cooling system out with water, I assumed you refilled with water and then ran the motor for a few minutes with the heater control turned to high and then dumped that out.  That's how you flush all the acidic waste antifreeze out of the entire system including heater core.  Then you get the rest out of the block by removing the drain plug from the block if you can find it and get to it.

I'm 99% sure there is no drain plug on the block, as it's not even mentioned in the service (shop) manual, let alone the owners manual.

And yes that's how I flushed the system -- ran the engine from cold, to operating temperature, with heater on high, and then shut the car off, waited about 10 minutes for that to cool a bit, and then dumped everything that I could (about 4L).

Odds are there is about 2.xL of highly-diluted coolant in there with the new 50/50 mixed stuff, and what I will probably do is IF the colour of the coolant isn't neon green by tomorrow (ie: if it got mixed, it wouldn't be as green as it was when it went into the rad), I will re-do this procedure after talking to someone at Mazda's service dept. about it.

[Wolfe]

Odds are there is about 2.xL of highly-diluted coolant in there with the new 50/50 mixed stuff, and what I will probably do is IF the colour of the coolant isn't neon green by tomorrow (ie: if it got mixed, it wouldn't be as green as it was when it went into the rad), I will re-do this procedure after talking to someone at Mazda's service dept. about it.

Sounds about right.

I agree with Artic, check the strength of the antifreeze with a gauge to be safe.

Me thinks you're too diluted since you ran water through the system first.  I'd measure the level of glycol with one of those gauges with the ball and needle just to be sure you are at -35C. 

[Squishy]

The coolant in the block does not drain through the radiator drain plug.  Sometimes the block drain plug is taken up by the block heater and is difficult to remove.

When you ran water through the system, you displaced the 50/50 mix in the block and filled it with 100% water.  You then refilled the radiator and reservoir with 50/50 mix, but the end result is more diluted than that because of the pure water in the block.

On most cars a radiator drain will take care of 80% or so of the coolant, so I just do that without a "flush".  I don't measure the coolant going in, either.  Just fill it, run it to hot with the rad cap off, then refill again.  Then go on a highway run to see if the temperature needle rises above centre.

[curls]

The coolant in the block does not drain through the radiator drain plug.  Sometimes the block drain plug is taken up by the block heater and is difficult to remove.

When you ran water through the system, you displaced the 50/50 mix in the block and filled it with 100% water.  You then refilled the radiator and reservoir with 50/50 mix, but the end result is more diluted than that because of the pure water in the block.

On most cars a radiator drain will take care of 80% or so of the coolant, so I just do that without a "flush".  I don't measure the coolant going in, either.  Just fill it, run it to hot with the rad cap off, then refill again.  Then go on a highway run to see if the temperature needle rises above centre.

If I think about it this way... (getting technical for no other reason than to say I did)

capacity: 6.5 litres (thereabouts)
drained: 4 litres
that leaves: 2.5 litres of coolant in the system
added water: 4 litres
ran engine which mixed the water/coolant to be about 61.5% water, 38.5% 50/50 mix, = 19.25% pure coolant
drained: 4 litres
added: 4 litres of 50/50 premixed.  ((4*.5)+(2.5*.1925)) = 2.48125 litres of pure coolant, 4.01875 litres of water, leaving a 38:62 mix of coolant to water.

By this calculation, I would need to add .12*6.5L = 0.78L of pure coolant (non-premixed), to achieve the desired 50/50 ratio.

So, I'll drain 780ml from the reservoir and replace it with pure coolant, and then run the engine for a while for it to mix.   Will adding to the reservoir actually mix the coolant in there in short time, or will it not get used until something happens that isn't a course of normal operation?

[barrie1]

To me you still may have air in the system. I suggest running the engine when hot and also the heater on MAX as well fan included. Leave the radcap off of it and let it run, have some extra fluid ready to replace what is burped out. This can take a 1/2 hour or so but keep doing it until you have lots of heat in the car and its stops burping. Airlocks can be a major pain but easy to remove if you are patient enough and do it long enough. How is the thermostat as well as its probably due also. Just do the systemover again and save the fluids if you have to after a stat replacement. You can even pull the bottom hose of the engine to be sure you have all the fluids out as well. 

[Allen]

wouldn't it have just been simpler to take it to a garage and have it done  , all this messing around hardly seems worhtwhile

[curls]

wouldn't it have just been simpler to take it to a garage and have it done  , all this messing around hardly seems worhtwhile

I like to DIY, especially now that I have my own garage.

[safristi]

Fack making a Long Island Iced Tea is simpler...Just Flush & Go.......top it up wif 60/40 antifreeze and yer COOL MAN

[curls]

I just talked to a friend who works in Parts at a Mazda dealer here, and he talked to one of the service guys.  They confirmed that the system holds 6.5L but you normally can only drain 4L because the rest is in the bottom of the block, and in the heater core.  My suggestion to take about 750mL out and add 750mL of straight coolant was acknowledged as being valid by the service guy...

[Squishy]

Yup that should work, although in some cars the coolant in the reservoir doesn't circulate much.  If the service guy okayed it, you might have the same system as in the Escape where the reservoir is basically the top of the radiator (and thus drains along with the radiator through the drain hole).  If not, you may be better off draining that much fluid from the radiator and re-adding.