I'll have to go through my records, but I believe both of my V8s have their original Coolant. I know I've changed the coolant in my V70R when I did the heater core a few years ago, but I used Genuine Volvo stuff as recommended.

That reminds me. We have a 2001 Alero in the family. It was my grandmothers, but she no longer drives. It has 8000 (yes, that's right. 8k) miles on it, and I believe it has the original dexcool in it. I really need to have that flushed asap.

 

I had it done this year at the 5 year mark. I prefer to do my maintenance myself but this was one that the $125 price at the dealer was worth the PIA cost associated with doing it myself.


Sent from my iPhone using Tapatalk

 

I had it done this year at the 5 year mark. I prefer to do my maintenance myself but this was one that the $125 price at the dealer was worth the PIA cost associated with doing it myself.

Sent from my iPhone using Tapatalk

I may take that route as well since in my simple looking at the system, it looks like a pain to flush the 3.2L engine without taking hoses loose. I've more research to do first.

 

I changed the coolant on my S60R a bit past 100k miles. I was shocked at how "new" the old coolant looked. I probably won't bother changing it on either current car unless I see signs of leaks or other problems.

 

So this past weekend, I did a coolant flush on my S80 since it is a used car (8 years) with lots of miles and the coolant was a somewhat dark reddish brown color. Didn't smell funny or seemed to have any oil residue as far as I could tell.

I used distilled water (3+ gallons) to do the Heat & flush three times (until mostly clear water drains out) with the heater on High and then refilled with 100% Pentofrost NF coolant (Blue OEM, purchased at O'Reilleys). I used the 3/8" tubing trick that Don67 recommended (great tip) on the petcock drain outlet. A word about that petcock: It was obvious it had never been turned and with working it back and forth (a little open then close, repeat with a little more open, repeat...) it finally backed out enough to get a good stream of hot coolant out. Just be careful and DON'T break it as it is plastic and finding a replacement seems to be a pain. BTW: Adding the 100% Pentofrost NF to the already very diluted old mixture and new distilled water should put me close to the 50/50 recommended mixture rate. With draining the radiator at the petcock, you only get about 4 Quarts of the 7.9 Quarts in the total coolant circuit.

http://www.pentosin.net/specsheets/Pentofrost_NF.pdf

I'm nice and blue again! I'll likely never have to change it again.

Thanks for everyone's sharing of their DIY experience on this.

 

I used distilled water (3+ gallons) to do the Heat & flush three times (until mostly clear water drains out) with the heater on High and then refilled with 100% Pentofrost NF coolant (Blue OEM, purchased at O'Reilleys). I used the 3/8" tubing trick that Don67 recommended (great tip) on the petcock drain outlet. A word about that petcock: It was obvious it had never been turned and with working it back and forth (a little open then close, repeat with a little more open, repeat...) it finally backed out enough to get a good stream of hot coolant out. Just be careful and DON'T break it as it is plastic and finding a replacement seems to be a pain. BTW: Adding the 100% Pentofrost NF to the already very diluted old mixture and new distilled water should put me close to the 50/50 recommended mixture rate. With draining the radiator at the petcock, you only get about 4 Quarts of the 7.9 Quarts in the total coolant circuit.

The fact that roughly 50% drains each time is kinda convenient. You simply perform repeated flushes and then add a full jug of pure antifreeze to get 50-60% concentration.

re: Petcock - Yeah, it's important to realize that it's (a) flimsy plastic, and (b) not a fully-threaded valve but rather a simple twist-lock/unlock system. No need to turn it far (or hard).

 

The anti-freeze mixture in engine coolant is there for more than just keeping the coolant from freezing at low temperatures. It also acts as an anti corrosion agent/ sacrificial anode. This is necessary to prevent galvanic corrosion in the cooling system as there are a variety of metals used in the cooling system(steel water pump, copper/brass in the thermostat, aluminium in the block and radiator). Over time the coolant loses its anti corrosive properties and this can cause parts to start to corrode(often the water pump). No idea why volvo dosn't specify a change interval but changing it is certainly a good idea.

 

Dang! What the heck happened to those impeller blades on the left?!?

 

A $10 coolant strength tester is a good investment for anyone with basic DIY abilities.

 

That's an awesome tip, Warpedcow. And testing the anti-corrosion properties of the antifreeze is really straightforward. You only need a multimeter. The galvanic corrosion happening in the system is proportional to the voltage generated between the fluid and the ground of the vehicle. A new coolant will generate around 0.01V. It is acceptable until 0.05V when it should be replaced.

The little thing with a needle is just a densimeter. It will tell you what the ratio coolant water is. You still have to measure the voltage to evaluate if the coolant is in good condition or not.

 

You still have to measure the voltage to evaluate if the coolant is in good condition or not.

Not to be argumentative - I learn new things in this forum on a regular basis - but can you back that up with a credible third-party link? It sounds like a bit of Euro-car hocus-pocus to this old-school guy.

 

Exactly.. Any corrosion that happens in a system with an electrolyte is a galvanic reaction, pretty much like a battery in a remote control (galvanic battery). Each metal in the system (like different metals in a water heater) has different electronegativity. This defines how they are going to donate electrons to other metals that are more electronegative. This transfer of electrons is what corrodes one metal (the piece of zinc attached to the boiler) while the copper keeps shiny (that's called Cathodic Protection and is also used in railroads and cell phone towers for example).

The antifreeze anti-corrosion properties are there because it is an "electric insulator" fluid. Once it gets old - I don't know if it wears or if metal particles from the system contaminate the fluid - it starts conducting more electricity and making galvanic corrosion rate to increase.

There is no source I could find that tells the math of applying this science to a cooling system, but it is basically the same thing as a battery. However, you want that battery to supply as little voltage as possible. At another car I tested before, this number came from 0.01V when new antifreeze was in to 0.03V after ~5 years and ~40k miles, still looking good. What is a limit number I actually don't know. I've seen people getting 0.07V in really dirty (by corrosion) antifreeze so I assume 0.05V would be a good number to tell it is getting bad.

As an interesting fact.: The zinc protection in a water heater also prevents lixiviation of copper: which is basically chlorine from the water arresting copper atoms ans putting them in solution. It can be harmful to ingest copper over an extended periodof time as it is a heavy metal to some extent in your organism.

Well long story short, I have studied this subject before in depth and know it by the book. As I said before, no sources of studies applied directly to this subject were found in my short research in the past few minutes, but the theory is explained above!

PS: You see how the water pump pictured up there had the impeller corroded so thin that it collapsed by the forces when it is spinning? On the other hand the aluminum body is dirty, but retained 100% of it's shape? That's because in the same media, iron has a lower electronegativity than other metals in the system, and corrodes first. A little bit different in this case since aluminum is actually the first metal to corrode, but the aluminum oxide forms a very strong and thin protective layer that ends up protecting the aluminum itself. Funny to say, but aluminum "rusts" instantly. However this rust is very thin and impermeable, protecting oxidation to further occur, as a coat of paint.

 

Very cool tip. Thank you both.

Can't wait to test the coolant in my cars now. Will be curious to see how the fresh blue stuff in my S80 compares to the four-year-old green stuff in my daughter's Elantra.

 

I had the same question, but after doing some research yes, one in the fluid and one on a nearby ground.

There's a whole sequence for determining whether or not a bad ground is causing increased electrolysis while driving, but it's a bit involved.

One odd thing is that my readings are not stable. The meter jumps to 0.25 volts or so and then "counts down" towards zero. Removing & retrying yields the same result again and again. I can't get a stable reading on the meter.

 

I was thinking about that over the weekend.

This method is really dependent on the probe's material. If probe tip is copper you will have different readings than if your probe is plated steel. So that explains having different readings...what you are actually measuring is the "corrosion" happening as cause of the tip of your multimeter interacting with the other grounded metals in contact with the coolant. Also matters how far the probe is from these metallic parts.

What I concluded is that there is a correlation between how good the coolant is and what voltage you get. But that is only true for the same car using the same probes. Newer coolant will show lower voltages, as long as the car is the same and the probes used are the same.

All-in-all this is not an easy way to evaluate a fluid if you don't know what reading you have for a fresh fluid.

I read my car and had 0.17 volts over the weekend, which means nothing in comparison to Don's 0.25 since it was most likely a different probe.No fluctuation though. I can't really understand why you see this counting down to zero on your meter...

 

It's so cheap and easy to change the fluid, I'd just suggest one do that every 3 years or so and not worry about it.

 

Is the radiator drain valve a 1/4 turn valve? My 2007 S80 probably never had the coolant changed. The plastic valve handle was in the vertical position. It can be turned counterclockwise to the horizontal. Nothing drains. Looking in the valve outlet looks like the plastic plug part of the valve. Coolant is clean blue, but time to change. Should this valve be turned more than 90* to open to drain? Don't want to force and break the valve.

 

I changed mine over a year ago but from what I recall it took more than a quarter of a turn to open it. Also felt flimsy and was hard to open but I managed to do it with a pair of pliers, which I don't really recommend because I thought I'd break it at some point. It'll screw "outwards", towards the engine, so maybe try jiggling it. Also leave the lid off the expansion reservoir, I think that might help in not creating a back-pressure.

 

Thank you for your quick response.
Just tried again to open the valve. The valve goes to what feels like a hard stop when the handle is horizontal. It also does not appear to move laterally outwards toward the engine. Perhaps I will have to gently massage the valve with a pliers by pulling on the handle. For now I have sprayed silicone on the plastic hoping it will turn easier. Will address later.

 

Forum;

I realize this is a somewhat older thread, but I ran across it during some research...I have been studying this subject at length and wanted to ad some clarifications to a couple of points that were incorrect or unclearly made...the intent is not be be a know-it-all (I surely don't!), but to point out some misunderstandings...because if you understand the science, manners of detection/prevention become clearer hopefully...!

10V8: Posting No 8. "anti-freeze mixture in engine coolant is there for more than just keeping the coolant from freezing at low temperatures. It also acts as an anti corrosion agent/ sacrificial anode."...first part about no freezing at lower temps than simple water, is spot-on...not so much the second part about acting as a sacrificial anode... Coolant cannot be a sacrificial anode as it is not metal...it prevents galvanic corrosion by making coolant 1. non-conductive and not making the electrical connection between different metals occurring in the system (with no conductivity, no galvanic currents can flow, so no erosion takes place!), and 2. anti-freeze contains some neutralizing components which further passivates what would otherwise be an roaring electro-chemical party!

Don67; From post No 13. Those cheapo Coolant testers you refer to typically only test specific gravity and therefore only anti-freezing characteristics...an important part, but they do not test the level of conductivity, and that's what determines and affects the Galvanic action...the best way to test this is through indirect Galvanic Voltage tests...the lower the better!...because GV is what drives anode erosion.

Waredcow: From post No. 16 "same thing that happens in the hot water heater in your house, and why there is an anti-corrosion bar that should last 20-30 years in those. The heating/water flow actually generates some electrical current and that can corrode things unless you have anti-corrosion stuff in your coolant, or in your hot water heater, it's some metal bar of some sort that is designed to absorb the corrosion over many years."
Similar, but Galvanic Corrosion is a result of not water flow, but electrical conduction through conductive water, between different metals in the system (in your car, Iron block/Alu head, Rad, Heater Core, WaPu Housing, etc. ), made worse when it contains minerals/ions and is thereby made conductive...distilled/de-ionized water obviously does not have these.
In the case of your home water heater, since the (open) system must pass what's coming down the pipe, and cannot be filled (like a closed system can) with non-conductive "special" water, so a sacrificial anode (of zinc, lowest on the Galvanic totem pole, and therefore it will erode before any other metal except magnesium!) is installed, to corrode preferentially to the more important and precious components of the system (Iron Heater, copper pipes, brass components).
"20-30 Years"...that's a prediction which you shouldn't make as it is very much a function of the minerals in the water coming down the pipe...my brothers house (well water) will dissolve up a water heater zinc in two years, like a lolly pop! At my house (good city water which I can directly add to an aquarium) it has lasted 10+ years sofar...

GusCo; ...has it right and gives very good info, but I'd like him to explain the term electronegativity vis-a-vis anode/cathode station on the Galvanic Series ...from Post No. 17 : "iron has a lower electronegativity than other metals in the system, and corrodes first." I would expect Alu to be the anode which erodes...? Could this be where we must consider and take into account Cathode / Anode ratio?

Reference Galvanic Series Chart: View attachment 49169

Galvanic corrosion is also why I recommend against installing those shiny Alu radiator...besides being the eroding anode in the galvanic couple with the iron block, they are also not as easily repairable (by soldering) as a brass Rad. See also: http://www.sw-em.com/Cooling_System.htm#galvanic_corrosion_in_the_cooling_system

Cheers