Coolant Question

Phaeton · Post by **Phaeton** » 28 Apr 2010, 19:36

Hey guys, I had an inspection done the other day and the mechanic said I should put the blue volvo coolant in my car instead of the green 50/50 mix. Any truth to this?

Post by **JDS60R** » 28 Apr 2010, 19:53

Yes,

The Volvo coolant is a HOAT coolant where most of the others are OAT coolants. It's not best to mix them.
HOAT's contain a Hybrid Organic acid technology so it includes what is in the OAT's along with things like sebacic acid and a small amount of silicate. HOAT coolants are used in heavy diesel trucks to deal with the extreme heat, cavitaion and loaclized boiling issues with a high output turbocharged engine.

That being said many have used a regular OAT coolant without issue. I have seen a few issues with OAT's while repairing so we now only use HOAT's if the car is turbocharged.

So I think OAT's will work but the Volvo HOAT is better. Its what I use in my car and the ones I repair.

Also use demineralized or distilled water and a new, tested, radiator cap.

Post by **shiloh51933** » 28 Apr 2010, 20:17

JDS60R wrote:Yes,

The Volvo coolant is a HOAT coolant where most of the others are OAT coolants. It's not best to mix them.
HOAT's contain a Hybrid Organic acid technology so it includes what is in the OAT's along with things like sebacic acid and a small amount of silicate. HOAT coolants are used in heavy diesel trucks to deal with the extreme heat, cavitaion and loaclized boiling issues with a high output turbocharged engine.

That being said many have used a regular OAT coolant without issue. I have seen a few issues with OAT's while repairing so we now only use HOAT's if the car is turbocharged.

So I think OAT's will work but the Volvo HOAT is better. Its what I use in my car and the ones I repair.

Also use demineralized or distilled water and a new, tested, radiator cap.

So if your using the HOAT coolant for the turbo models what should someone use if they had a non turbo model?
I'd rather spend the extra $$ if its gonna make a difference or extend the life of my ride yah know. I believe mine
already is HOAT coolant running since day one, so why change a good thing, just looking for conformation.

Post by **FlyingVolvo** » 28 Apr 2010, 20:23

Volvo coolant is great stuff, but the fact is that thousands of us use the "green stuff" with no ill effects. As long as it is kept reasonably well changed, don't expect any issues with your cooling besides the usual suspects (thermostat, ECT, radiator crack).

Post by **JDS60R** » 28 Apr 2010, 20:42

Oh man - another coolant thread.

I stay out of these arguments. I only know what I have repaired and tested. My advice is to stick with the Volvo coolant and demineralized or distilled water. Also test or replace the cap

Others will disagree.

I promise that using the coolant the car was designed for will not hurt it.

voltech1 · Post by **voltech1** » 28 Apr 2010, 21:13

If your running volvo green coolant it is chemically the same as the blue just different color. Thats what engineer told me. The green color has not been used for a while. So some mechanics will recommend changing your coolant based on how long its been in your engine. otherwise what all these guys said!

Post by **Ozark Lee** » 28 Apr 2010, 23:21

I run Zerex G-05 in all of mine. It is HOAT and it is phosphate free. I think it is less of an issue in the US but the phosphate part can be a big issue when combined with some European tap water.

G-05 is hard to find but normally NAPA has it for around $12.00 / gallon. It looks funny since it is Yellow but I guess that is no funnier than Blue when you are used to looking at the green stuff.

...Lee

_HighVoltage_ · Post by **_HighVoltage_** » 01 May 2010, 08:14

So what CAN happen if you don't use Volvo coolant, or mix coolants?

The reason I'm asking is because a few months ago, I was running a bit low on coolant. I took a look - the color was green. So I went and bought a bottle of the 50/50 PEAK green coolant. I haven't noticed any overheating issues. But it does drip from somewhere...can mixing coolants damage the hoses?

Post by **JDS60R** » 01 May 2010, 10:28

The problems we have seen with not using the proper coolant is localized boiling for the turbos. One modded turbo blew the motor and cracked the clyinder walls in the midline. I am currently in TN and the hot weather and performance minded indiviuals always tests the boundries of the cooling system. If I were back up north I don't think this would be an issue at all. Hard acceleration witha turbo at 100 degrees ambient can realy make some heat.

Your question about what happens when you mix is a valid one. Currently the investigations are ongoing. Most engineers will agree that under 10% of a different coolant mixed with another will not casue issues. At 15% problems occur and they vary per coolant mixed.

We have seen greater gasket deterioration when mixing coolants.
We also see a slighlty higher level of electrolytic corrosion but it is so small a difference I don't think it matters.

The heat transfer of the Volvo coolant and demineralized or distilled water is fantastic. Do not think your car came from the factory with distilled water. On the whiteblocks you can run them hard and then bring them into the garage and shut them down after a few minutes of cool down. If you hear the motor ticking as it releases heat then you need a better coolant. This has been the consistent feedback from our customers. They love that it doesn't tick anymore. Long story short the Volvo coolant gave better localized boiling control . ( the exhuast will always tick a little - but we are talking about the motor- open the hood and listen -if you hear the motor ticking - go back to Volvo coolant - the clyinder walls on the whiteblock do not like localized boiling and will give way eventually)

My suggestion is to use the Volvo coolant ( or similar HOAT) and demineralized or distilled water. Change it every 5 years (max) and pressure test the cap annually. If you have a leak - fix it - do not use leak stop products . The pressure cap has a very small amount of give in its spring pressure mating surfaces. Even a little piece of fiber from a leak stop product can delete the pressure holding ability of the cap.

You can use regular all makes coolant but it does not offer the same protection under extreme circumstances. Take it easy on the car and you will be fine. If you are going to "use" the power the car has - or just want better protection - Use the Volvo coolant (or similar HOAT) with distilled or demineralized water and a tested cap. I have heard G-05 is a good HOAT and also BMW coolant is the same exact coolant as Volvo - The bottles I have of the BMW coolant have the same ingredients in the same order (less the bittering agent Volvo puts in to drive away animals from drinking it). On occasion my local Car Quest puts the BMW on sale for $10. I get demineralized water from Pep Boys. RO water or double distilled are my second favorites. Just don't use tap.

_HighVoltage_ · Post by **_HighVoltage_** » 01 May 2010, 14:29

Thanks for the informed response!

The ticking that you mentioned. I've heard it, but it only ticks 2-3 times, and that could be the exhaust manifold as you mentioned.

My car is a NonTurbo, and it's been driven very carefully. My clogged PCV doesn't like high revs

I guess I'll stick with the PEAK stuff for now.