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Engine coolant/anti-freeze change.


Guest SwiftBuicks

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Guest SwiftBuicks

Since my 3.8 engine hasn't had a change of coolant in over two years when the odometer turned 100,000 recently, I decided to do a thorough job of it. I used the shuttlecock on the radiator and drained as much coolant as I could. That constituted about 6 quarts. Then I filled the radiator to it's limit with water and a few table spoons of Baking Soda (an old farmer told me that helps clean the system and I have done that on most of my cars). The recommended procedure would be running the car and heater with the plain water mix for a few days, drain it and then fill with 50/50. However, I have decided to try and flush the system thoroughly, so I ran it with the mixture for about 15 miles and then drained it. I was surprised at how thick it was with anti-freeze. Consequently I repeated the procedure of filling it with plain water and baking soda then driving it. Now, I am waiting for the engine to cool down before I drain the plain water out. I suspect that the waste water will still have anti-freeze in it. However, I am skeptical that if I add the glycol mix filling the radiator, I won't have a proper ratio given that the engine must hold more than 6 quarts or the radiator fill. I saw in a manual that the capacity is roughly 11 quarts. Should I add pure anti-freeze instead of a mix? I am also planning on using a Flush as directed on it's container. That says drain the anti-freeze then add the Flush and fill with water. After that you run the engine with heater for 20 minutes. Then they say drain the radiator, fill it with plain water, run it for another 20 minutes and then drain. I followed this procedure with another vehicle but wonder if I have the right ratio of glycol in that engine given that I added 50/50.

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Guest Corvanti

some may have problems with what i did flushing out my reatta, but the coolant was very, very rusty.

with the radiator cap off, i pulled the top radiator hose off at the radiator, started the car - with the heater on - and when the thermostat got to operating temp, the cruddy coolant flowed fast. once the radiator (not the entire system) was about empty, i'd fill with luke-warm water and repeat the process until clear. also monitored the coolant temp so it wouldn't go over 210...

filled with a radiator flush product and drove around 30 minutes. after cooling, repeated the above process. i got a total of 2 gallons of coolant in her - that includes after letting the system "burp" out air a couple of times.

during cool down periods, i also siphoned out the coolant "overflow tank". used hot water, a little bit of "flush" product and brushed with a stiff bottle brush to clean the crud out of the tank, then ran water thru the the tank until clear (took the hose off at the radiator cap to clean it out, too). siphoned most of the water out and filled with coolant.

hope this helps! :)

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Guest Mc_Reatta

Typically as you found out, the radiator is usually approximately 50% of the system capacity. Therefore if you have completed flushing the entire system to your satisfaction, the final step would be to drain the radiator only and refill it completely with 100% strength coolant. This will result in close to a 50/50 water/coolant concentration once the system has been hot cycled a few times.

If you live in an area where you need to achieve a concentration other than 50/50, then you will have to make some adjustments. If you live in the frozen northlands and need a stronger solution, you may have to pull the lower radiator hose to the engine and turn the heater on as your draining the radiator to get most of the fluid in the system out. Then you would mix some coolant in the strength you need and use this only to refill the system. May take some time to get all the fluid needed into all the nooks and crannies in the engine block etc.

Once you accomplish the complete refill, then you should use a 50/50 blend solution (or your specific blend) to top the level off over its life.

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I just had this done to my car at 87K. The condition of the coolant leads me to wonder if it was ever changed. It took several machine flushes to get rid of all the accumulated junk in the cooling system. At this point, I am somewhat concerned still about the internal condition of my heater core and radiator. My mechanic suggested we run this coolant for a year and then flush it again. I have never seen such rusty congealed muck as what was in my cooling system. Funny thing is that the temp gauge never went above the midpoint. My point is to make sure YOU (all) don't neglect this aspect of vehicle maintenence.

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I have used the test paper for coolant. They're like litmus paper, you dip it in the coolant. They have two areas, one tests coolant strength (freeze protection) the other test acidity. The acidity is important for obvious reasons, damage to all metal parts and seals.

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Guest SwiftBuicks
Your local auto supply store should have hydrometers specifically calibrated for testing your coolant mix. They don't cost that much and if you are worried enough to post this question it might give you peace of mind.
First of all, I want to thank you all for posting here. Second, I already own a good hydrometer. I posted this question thinking that I didn't want to add 100% without some kind of reassurance. This was what led me to change the coolant. It was passable, but given that two years has elapsed since the last change, I decided to do a thorough job of it. Realize that we are in a mathematical progression here. The books stated that my engine, (I have a Riv so I was curious if they put it in the Reattas) the 3.8 liter, has a 13 Quart capacity. We'll assume that the radiator holds half of that. If you drain the radiator and then refill with water, run it, then go through the same process, you will never obtain a pure water solution. I've drained mine 4 times, I believe, and seen at least 13 quarts come out of it. The water drained hasn't ceased to look green, but the hydrometer gives me a zero reading. Now, here's the math, 13/2=6.5. However, I really saw only 5 or so quarts come out. to make it look simple you divided by 2 every time, but one should realize that isn't precise. I have 13-5 or 8 quarts of solution to start (erring on the side of caution). Then you dilute the solution once more by mixing it with pure. For matters of simplicity lets say you dilute by 1/2 each time. So assuming you have a 50/50 start, the second mix is 25/75, the third is 12.5% glycol, while the fourth is 6.75%. At this point I am going to add my new anti-freeze. If half of the solution is 100% and half is 6.75%, then the result will be under 70%. However, if you have a 25/75 mix added to a 100%, what will you have? Finally, and most importantly, one the Toyota 4-runner which I changed, ran a chemical flush, ran a water/baking soda mix and then drained and filled with 50/50, I'm seeing fluid leak plentifully through what I think is the water pump. I will change the pump, but I was wondering if the flush had anything to do with pushing it over the edge.
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I have to wonder of all the flush, flush, re-flush procedure isn't overkill (and expensive) for a cast iron block engine with cast iron heads. I think your time and money would be better spent by just flushing out the system and adding 1/2 of a small container of Bar's Leaks (liquid type stop leak) to the correct antifreeze mixture for you're area of the county. I always use distilled water mixed with enough high quality antifreeze to put the antifreeze tester into the range I want. No 50/50 stuff for me. I would rather mix my own in the radiator until I get it where I want it.

The Bar's Leaks will coat the freeze plugs and other parts to help prevent corrosion. It will also lubricate the water pump. I have been using the Barr's Leaks product for over 30 years in every vehicle I've owned and I have never had a freeze plug go bad. Water pumps are usually good for about 75,000 miles before they have a problem. I think Bar's Leaks is good insurance against cooling system problems.

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Guest Mc_Reatta

If your serious about completely flushing the system with the best results, you should install a tee something like this into the heater hose, pull the radiator and thermostat and go for it. Reinstall the radiator and lower hose and then refill with the mixture of your choice via the thermostat well until block and radiator are almost full, reinstall thermostat and upper hose and top off. It's the quickest, simplest and easiest way to completely flush the entire system.

post-55241-14313922521_thumb.jpg

I'm seeing fluid leak plentifully through what I think is the water pump. I will change the pump, but I was wondering if the flush had anything to do with pushing it over the edge.

Probably. The build up of gunk and deposits at the site of the leak probably sealed it up preventing a leak. Flushing this stuff out opened up the area so that it now leaks freely. I'd certainly replace whatever is leaking as well as installing new thermostat, hoses, and radiator cap if any deemed questionable, before sealing the system and adding new coolant.

To answer the question of diluted mix from incomplete drainage and addition of

new coolant:

Going with your given capacities for system and radiator and believed end state of 6.75% solution after 4 flushes and refills:

After draining 5 qts from radiator, system has 8 qts at 6.75% or ~0.5 qt of coolant in it.

If you can get 5 qts of 100% coolant into the radiator, you will then have 13 qts of mixed coolant with 5.5 qts of 100% coolant in it which will result in a mix of 5.5/13 x 100 or ~ 42%

If that's not close enough for you, you will have to get more 100% coolant into the mix by ideally draining more than just the 5 qts in the radiator to start.

If you can get an additional qt out by pulling the lower hose, then you would have:

7 qts x 6.75% = 0.47 qt + 6 qts (100%) gives 13 qts with 6.47 qts (100% coolant) or a mix of 6.47/13 x 100 = 49.8 %

Won't contest Ronnie's results of additing of Bar's stop leak into the mix, but any good quality coolant you add will have corrosion preventives and pump lubricators in it already, so adding more is probably not necessary.

Edited by Mc_Reatta (see edit history)
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Guest SwiftBuicks

Thanks for the replies. I have been wondering about Bar's Leaks product as an additive. I'm using the Walmart standard anti-freeze so the Leak product should help. I have the LeSabre up to snuff now. I can't see how doing an extra drain or two of the radiator would not help. In the case of the LeSabre, it wasn't costly, took little actual time and has rid the system of most of the old questionable coolant. Now, I'm working on the Riviera. I put in the flush this morning with water. This will be the second drain when it cools down. The mfg.'er recommends replacing the flush waste with water, then running the system for 20 minutes. The radiator core was rusted. I'm curious to see the fluid that drains after a flush here. The other radiator cores weren't rusted. By the way, there's still a bad whine coming from the Riviera belts and wheels. I am going to look at the water pump when I can. The water pump for the Toyota was o.k. I also wonder if the AC Delco tensioner wheel that I bought in June hasn't broken down already. The belt is fine. The alternator is new. Is there anyway to pinpoint a noise like that?

Edited by SwiftBuicks
details (see edit history)
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Guest PontiacDude210

I have noticed a similar gunk in the coolant of my Reatta. I am, however, terrified to flush the fluid because I have heard horror stories about fluid flushes eating the headgaskets. I notice you all recommend flushing with plain water. Is this the best plan of action? Also, I almost bought a T the other day to hook up to a hose, pretty universal I assume?

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Guest SwiftBuicks
I have noticed a similar gunk in the coolant of my Reatta. I am, however, terrified to flush the fluid because I have heard horror stories about fluid flushes eating the headgaskets. I notice you all recommend flushing with plain water. Is this the best plan of action? Also, I almost bought a T the other day to hook up to a hose, pretty universal I assume?
If the outside temps are moderate, you can run your vehicle on plain water. I've been working on old cars for 40 years and used a chemical flush for the first time this time around. The directions specify running the engine for a short time with it in and then washing it out quickly. I did see a difference in the color of the waste water, but my engines seem rather clean. However, that gunk is not what you want in your system. Make sure you are careful when using a hose and a running engine. Wear a short sleeve shirt and keep a close eye on the fans. As to more on this drama of mine, man vs. machine Arnold style, I bought the Bar's No Leak/Lube stuff with the pellets. Has anyone else used this? I put a bottle in my toyota 4-runnner along with new glycol. Now I have to drive it to mix it all. As to worrying about Freeze Plugs, the '89 Riv lost one two years ago. It cost me $1,100. to replace the old with new. The engine had to be taken out of the car as this particular plug was inaccessible.
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