Burst silica bag - can't get it solved

[Colin_v40]

Hi,

I'm new to this so I hope I'm doing this right. I have a 2013 Mk7 1.6TDI golf. My heating stopped working about 5 weeks ago and I took the car to a mechanic who found it was a burst silica bag. To fix this, he replaced the heater core and flushed the system thoroughly, until he was sure it was clear. The overflow tank and thermostat were also replaced, to be on the safe side.

Having done this, I took the car back but the heating hasn't been working right since. I've had it back several times and now, having tried everything else, he checked the heater core again. And, once again, there's silica in it. A small amount, nonetheless enough so that the heat is only working on one side of the car.

I'm wondering if this is a problem that anyone has had success fixing. Will the heating in my car ever work correctly, and is it even possible to ensure that all the silica has been removed from the system? I can't see myself holding on to this car for too much longer if this is going to be an ongoing problem.

P.s. why has this problem never been addressed by VW? Clearly, many people have fallen victim to it and yet, there's no recall and no advice to change/remove silica bags, despite this being relatively widespread.

I'm really at my wits end with this, and it's already cost a lot of money, so any help would be appreciated.

Thanks.

Hi.
My heater stopped working too. 2014 model.
Took it to my mechanic who drained system, removed and flushed coolant tank, replaced heater matrix and water pump. Bloody silicon had blocked up the heater matrix and pump. All flushed through, silicon bag removed and engine now running at correct temperature and heater working better then ever.
Total cost over £800. Absolutely distasteful that VW can get away with this. I'll never own another one. Been one of the worst cars I had had for reliability. Marginally worse than the Volvo before it.

 

[jimlloyd40]

Hi.
My heater stopped working too. 2014 model.
Took it to my mechanic who drained system, removed and flushed coolant tank, replaced heater matrix and water pump. Bloody silicon had blocked up the heater matrix and pump. All flushed through, silicon bag removed and engine now running at correct temperature and heater working better then ever.
Total cost over £800. Absolutely distasteful that VW can get away with this. I'll never own another one. Been one of the worst cars I had had for reliability. Marginally worse than the Volvo before it.

That silicon bag should be warranted for life. I've read too many stories like yours. I was going to remove it myself but I'm afraid I would break it trying to get it out.

 

[IWMTom]

Hi.
My heater stopped working too. 2014 model.
Took it to my mechanic who drained system, removed and flushed coolant tank, replaced heater matrix and water pump. Bloody silicon had blocked up the heater matrix and pump. All flushed through, silicon bag removed and engine now running at correct temperature and heater working better then ever.
Total cost over £800. Absolutely distasteful that VW can get away with this. I'll never own another one. Been one of the worst cars I had had for reliability. Marginally worse than the Volvo before it.

It's not silicon that blocks the matrix, it's the casting sands from when it was manufactured. Very common fault.

 

[ashulton]

Has anyone managed to get this problem covered by their warranty? We have a 5 year old Golf with an extended warranty and they say it’s consequential damage so won’t cover it.

 

[IWMTom]

Has anyone managed to get this problem covered by their warranty? We have a 5 year old Golf with an extended warranty and they say it’s consequential damage so won’t cover it.

Sorry to disappoint, but if you've got one of those aftermarket warranties where consequential damage isn't covered you probably won't get anywhere.

Who's the provider?

 

[ashulton]

It’s with VW themselves, in the documentation is say consequential damage is covered, (page 8), were currently going back and forth with the dealership, but wondered if anyone had had it covered so I could show them!
https://insurewithvolkswagen.co.uk/media/1107/35239_vw_extended-warranty_dec19_nav_v1.pdf

 

[IWMTom]

It’s with VW themselves, in the documentation is say consequential damage is covered, (page 8), were currently going back and forth with the dealership, but wondered if anyone had had it covered so I could show them!
https://insurewithvolkswagen.co.uk/media/1107/35239_vw_extended-warranty_dec19_nav_v1.pdf

That's something I suppose.. I've had horrendous experiences with aftermarket warranties but if it's provided by VW you should at least have SOME leverage!

It wouldn't surprise me if they end up using this exclusion though: "We will not pay for sudden failure due to lack of oil, fuel, lubricants, anti-freeze, hydraulic fluids or additives; or foreign matter entering the fuel, cooling, air conditioning or lubrication systems."

 

[Gordon F]

Our dealer checked against our VIN and said we shouldn't have a silica bag even though the header tank had the mit silica logo.
Unclipped our tank (double wall) and even though you can flip it over without disconnecting either of the pipes, or unplugging the loom, you can see the bag but it is impossible to see if it is damaged or not.
Ordered in a new tank which came without the bag (5Q0121407M @ £23.75 + VAT) plus 1L of coolant (G12E050A2 @ £5.61 +VAT) and swapped them over. 5 minute job
Checking the silica bag means dissecting the old tank with a saw. With ours, the bag was mounted in a frame in the outer wall of the tank and was intact. It's also pretty robust and its difficult to see how it would split through normal use.

 

[jimlloyd40]

That's something I suppose.. I've had horrendous experiences with aftermarket warranties but if it's provided by VW you should at least have SOME leverage!

It wouldn't surprise me if they end up using this exclusion though: "We will not pay for sudden failure due to lack of oil, fuel, lubricants, anti-freeze, hydraulic fluids or additives; or foreign matter entering the fuel, cooling, air conditioning or lubrication systems."

But VW placed the "foreign matter" into the expansion tank.

 

[IWMTom]

But VW placed the "foreign matter" into the expansion tank.

¯\_(ツ)_/¯

 

[sGTImon]

What do I need to use to remove the bag ? And how

 

[Lth0ms0n]

How did he re-charge the coolant system, did he do it as-per VW's workshop procedure for it?

I've had a heating problem with my car which has recently been investigated by myself and my Dad. We haven't 100% solved it yet - we had it working then we flushed the system again (as you're supposed to do it 4-5 times) and since then, I've lost it again.

I flushed my car with 800ml of bio-degreaser to break down everything that was in it and when we tested the heater core while out of the car, we proved it wasn't blocked.

I don't think mine ever was, I think the heating problem started because the mechanic who replaced my timing belt did a lazy job and relied on the car self-bleeding itself after he re-filled the coolant. The only thing my Dad and I haven't been able to do yet is use a vacuum pump to re-charge the coolant - you're supposed to do that, according to VW, and then use a bleeding programme you initiate via VCDS once the job is done.

The reason I say this is we're both adamant there is an air-lock trapped in the matrix that will never be able to come out - owed to the bend in the pipes coming off the core (I have a Denso unit, they're quite severe) and the angle it leans back slightly at.

(Not the greatest picture but you get the idea - the Valeo system has different inlet/outlet pipes on it). The outlet is the top one and it has a 90º bend in it as it comes off the top of the core so it's really easy for air to collect there without being forced out - that would stop it heating fully as the coolant flows through.

The only way we can see around this is to vacuum all the air out so there's nothing there when you re-fill it, otherwise the water just finds the easiest way through it and that seems to be sticking to the passenger side of it.

Of course, it's difficult to say this for sure as we can't heat test it when it's in the car and we can't remove it to inspect it because all the water will come out. But given everything else we didn't discover (no sand, silica gel bag intact, even heat across the core when we flushed hot water through it) it's the only reasonable conclusion left to be drawn from it.

 

[Finglonga]

What do I need to use to remove the bag ? And how

I just pulled it out carefully, if it does burst it it wasy enough to take the expansion tank off and clean it out.

 

[fazGtdlimestone]

Are both denso and valeo units blocking up

 

[fazGtdlimestone]

How did he re-charge the coolant system, did he do it as-per VW's workshop procedure for it?

I've had a heating problem with my car which has recently been investigated by myself and my Dad. We haven't 100% solved it yet - we had it working then we flushed the system again (as you're supposed to do it 4-5 times) and since then, I've lost it again.

I flushed my car with 800ml of bio-degreaser to break down everything that was in it and when we tested the heater core while out of the car, we proved it wasn't blocked.

I don't think mine ever was, I think the heating problem started because the mechanic who replaced my timing belt did a lazy job and relied on the car self-bleeding itself after he re-filled the coolant. The only thing my Dad and I haven't been able to do yet is use a vacuum pump to re-charge the coolant - you're supposed to do that, according to VW, and then use a bleeding programme you initiate via VCDS once the job is done.

The reason I say this is we're both adamant there is an air-lock trapped in the matrix that will never be able to come out - owed to the bend in the pipes coming off the core (I have a Denso unit, they're quite severe) and the angle it leans back slightly at.
View attachment 215305

(Not the greatest picture but you get the idea - the Valeo system has different inlet/outlet pipes on it). The outlet is the top one and it has a 90º bend in it as it comes off the top of the core so it's really easy for air to collect there without being forced out - that would stop it heating fully as the coolant flows through.

The only way we can see around this is to vacuum all the air out so there's nothing there when you re-fill it, otherwise the water just finds the easiest way through it and that seems to be sticking to the passenger side of it.

Of course, it's difficult to say this for sure as we can't heat test it when it's in the car and we can't remove it to inspect it because all the water will come out. But given everything else we didn't discover (no sand, silica gel bag intact, even heat across the core when we flushed hot water through it) it's the only reasonable conclusion left to be drawn from it.

Did you get yours sorted I too have denso matrix with just warm heat passager side cold on drivers side both inlet and outlet on matrix get hot after a drive thanks