Coolant silica bag, to remove or not?

[GTI-Jay]

To those who change their coolant. Do we have a bleed screw on the gti's ? Or do you just burp out any air pockets ? TBH i've not even looked. Cos i can't say i've ever had a car longer than 5yrs from new. But if they're taking away MT's on the mk8, i may just keep this one til it falls apart.

 

[blaqsheep]

To those who change their coolant. Do we have a bleed screw on the gti's ? Or do you just burp out any air pockets ? TBH i've not even looked. Cos i can't say i've ever had a car longer than 5yrs from new. But if they're taking away MT's on the mk8, i may just keep this one til it falls apart.

It will remove trapped air from the system on its own. This is why some people notice slight coolant loss from their new car as VW can't fully bleed the coolant system from the factory.

 

[Hambert]

I learn something new every day!

I found this on Wikipedia (Coolant article: https://en.m.wikipedia.org/wiki/Coolant):

"A new class of coolants are*nanofluids*which consist of a carrier liquid, such as water, dispersed with tiny nano-scale particles known as*nanoparticles. Purpose-designed nanoparticles of e.g.*CuO,*alumina,[6]*titanium dioxide,*carbon nanotubes,*SILICA, or metals (e.g.*copper, or*silver*nanorods) dispersed into the carrier liquid enhance the heat transfer capabilities of the resulting coolant compared to the carrier liquid alone.[7]*The enhancement can be theoretically as high as 350%. The experiments however did not prove so high thermal conductivity improvements, but found significant increase of the*critical heat flux*of the coolants.[8]"

I don't know if it's 100% the case, but it seems the silica particles are there for enhancing the heat exchange performance of the liquid, not only its life.

More info: https://www.researchgate.net/public...in_a_Car_Radiator_with_Nanofluids_as_Coolants

I wouldn't take it out...

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[GTI-Jay]

Give Pentosin customer care a call. They're the ones who make the coolant for VW. They'll tell you what you need to know.

 

[2slowvw]

I don't know, personally I would just leave it in there. Its in there for a reason and there have been no wide spread issues with this bag ripping. Seems like more of an isolated case that a user here or there had. Remember the MK7 released in Europe years before it released here. Figured if this was an issue you would be hearing alot more about it.

 

[Strange Mud]

^^good point, but if it tends to fail after xx years I would rather replace my coolant 3x.

 

[ReadTheBook]

The way these cars are losing coolant I would say topping them off every now and then will keep the coolant fresh, so little bag of silicon is useless.

If you're losing coolant you have a leak. Simple as that. It's happening in droves and has been for some time. Both of my MK7s were affected for 20K+ miles before I finally had them both fixed last month. The leak is SLOW and I could never see any evidence of coolant anywhere but it was coming from the thermostat housing/flange and water pump seal. Could only be found under pressure test.

There's a reason they're on revision K of the thermostat housing...

 

[mk7_bk]

If its not broke, don't fix it. I see no possible gains or losses from removing or leaving so just leave it alone. If it rips people would know about it as a issue. Which it is not.

 

[Wrath And Tears]

If its not broke, don't fix it. I see no possible gains or losses from removing or leaving so just leave it alone. If it rips people would know about it as a issue. Which it is not.

But it can rip, and then it clogs the heater core. There were three threads about it last year.

 

[JWTS]

I learn something new every day!

I found this on Wikipedia (Coolant article: https://en.m.wikipedia.org/wiki/Coolant):

"A new class of coolants are*nanofluids*which consist of a carrier liquid, such as water, dispersed with tiny nano-scale particles known as*nanoparticles. Purpose-designed nanoparticles of e.g.*CuO,*alumina,[6]*titanium dioxide,*carbon nanotubes,*SILICA, or metals (e.g.*copper, or*silver*nanorods) dispersed into the carrier liquid enhance the heat transfer capabilities of the resulting coolant compared to the carrier liquid alone.[7]*The enhancement can be theoretically as high as 350%. The experiments however did not prove so high thermal conductivity improvements, but found significant increase of the*critical heat flux*of the coolants.[8]"

I don't know if it's 100% the case, but it seems the silica particles are there for enhancing the heat exchange performance of the liquid, not only its life.

More info: https://www.researchgate.net/public...in_a_Car_Radiator_with_Nanofluids_as_Coolants

I wouldn't take it out...

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There are no nanoparticles in VW coolant--or any other readily available coolant.

The packs are simply there to replace the sacrificial silicates that are depleted in use--they don't provide any additional benefit over and above fresh coolant. Mercedes and VW/Audi have used these for a couple decades, though they seem to be more prevalent now.

You can remove them and replace your coolant on a regular schedule, or leave them in. If you're just keeping the car for the warranty period, I'd see no reason to remove them. I pulled mine out. YMMV and all that

 

[JC_451]

Are there stories out there of this bag breaking?

 

[crxgator]

I replaced the entire coolant bottle. It was $8 new from VW.

 

[Carlosfandang0]

Is the bag a NAR addition? My UK GTi doesn’t have the bag and neither have I seen one on any other car here!


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[mk7_bk]

But it can rip, and then it clogs the heater core. There were three threads about it last year.

I agree that sucks, but how many people have heard of this/ had it happen? Does anyone know or was it just 1 guy? Say out of 10,000 gti’s how many people had this? Maybe 1-10? Its seems like a very small % of people I would think or else everyone would say do it, why not. Or maybe im wrong and everyone is doing it.


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[JWTS]

Is the bag a NAR addition? My UK GTi doesn’t have the bag and neither have I seen one on any other car here!


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https://www.golfmk7.com/forums/showthread.php?t=28421

Don't know about the petrol GTI, but obviously it's not strictly a NAR thing, and obviously they can break.

I doubt the incidence of them breaking is very high, since you rarely hear about it. That said, it can happen--and on the very small chance that it does, the repair looks pretty involved.

As far as why the manufacturer put it in there, the reason is pretty simple: extend coolant life. These have been used in OTR diesel trucks for quite a while, where extended service intervals are pretty key to reducing costs. b