GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Topic started by: Rob_benton on 28 November 2019, 17:12
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Hi
I want to replace my tank and the dealer says the tank doesn’t contain the silicon bag from the factory.
Has anyone replace their tank and did you buy a new bag ? I want to replace the tank as it’s aged and peace of mind regarding the bag.
Thanks
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Looking into this further, you can buy a tank with and without the bag depending on the part number.
And other forums recommend having a bag to prevent future corrosion.
Question now is, is it worth replacing the bag every so often for peace of mind ?
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Peace of mind?
The coolant mix has anti freeze and anti corrosion inhibitors by design.
If the latest coolant tanks do not have a silica bag, do you have desisive evidence of the benefit of having a silsica bag present?
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Peace of mind of a old bag splitting. I read more and more of it happening online.
Strange that not every Vw Golf has a bag. Do some engines years have a material that corrodes more than others ? I don’t know.
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Been following this from when it emerged on the heating failure post. When is the bag supposed to have been deleted? My March 2019 car has one. Mine looks quite robust - not like the tea bag thing in the YouTube video! I’m not concerned at this stage in my car’s life, but interested.
I would agree with the view that coolant is designed to inhibit corrosion, so why the need for this bag? I’m guessing that it’s a bit like a magnetic drain plug - leaching corrosive particles from the coolant.
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I had read that G13 doesn’t contain as much protection as it used to. I don’t know if it’s true. Would Vw spend time and money fitting a bag if it wasn’t necessary?
I’m thinking of just fitting a new tank with bag every few years. Doesn’t cost much to prevent big bills if the worst was to happen.
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Removed the bag from mine years ago, I have seen what happens if the bag bursts, virtually everything needs replacing.
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Just to be clear, this silicon bag is only found in cars with climate control fitted from the factory. As this was an option I didnt spec (option in ireland back at launch) my car has no such pouch. One less thing to worry about i suppose for me and other owners without climate control which I suspect are few and far between.
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How much are the two header tanks, ie with and without the bag?
And do you have the part numbers please?
Thanks
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Sorry I don’t have the codes but my garage said the exact tank for my car was about £18.50 + vat so should have the bag. I’d obviously check !
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I went to a dealer last Friday and bought a new tank @ retail £23.06 + vat total price £27.67.
The current part number is 5Q0121407T, there has been a part number ending in M. I checked while there for the silica bag and couldn't see one, the parts guy said there had been quite a few cars that needed the heater matrix changed because of the split silica bag. The bag isn't available separately but all tanks have it. Check for the handbook information symbol on the tank to the right you will also see the G13 symbol and further to the right the words mit silikat (with silicate).
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I went to a dealer last Friday and bought a new tank @ retail £23.06 + vat total price £27.67.
The current part number is 5Q0121407T, there has been a part number ending in M. I checked while there for the silica bag and couldn't see one, the parts guy said there had been quite a few cars that needed the heater matrix changed because of the split silica bag. The bag isn't available separately but all tanks have it. Check for the handbook information symbol on the tank to the right you will also see the G13 symbol and further to the right the words mit silikat (with silicate).
So did your old tank have a bag ? And if it did, are you fitting a tank without one ?
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Does anyone have a picture or a link to a picture showing this bag, as I'm feeling a little paranoid!
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Does anyone have a picture or a link to a picture showing this bag, as I'm feeling a little paranoid!
Here’s one being removed on a US GTI;
https://www.youtube.com/watch?v=-GWRejR7U0w
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Does anyone have a picture or a link to a picture showing this bag, as I'm feeling a little paranoid!
If your tank has a bag it will say mit silikat next to G13 written on it.
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Just checked my car a 2014 build estate..coolant tank does not state "mit silicat"...& shone a bright torch through the side of the tank to illuminate the whole inside...no silica bag...& I have the top end 2 zone climate...as someone thought all with climate got the silica bags as standard...
VW obviously considering a silica bag is cheaper than the correct amount of G13...extreme penny pinching...which also explains the lack of service date change for the coolant which used to be 5yrs....
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This is from a Vw self study
‘ Coolant Expansion Tank with Silicate Repository
The coolant expansion tank contains a silicate repository. Silicate is used to protect the aluminum components in the coolant
system from corrosion. There are silicates in the G13 coolant, but they are used up over time if the engine is subject to high
thermal loads.
To compensate for the silicate consumption, silicate is taken from the repository and added to the coolant. The silicate
repository provides additional protection against corrosion for the aluminum components in the coolant system over the entire
lifespan of the engine.’
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This is from a Vw self study
‘ Coolant Expansion Tank with Silicate Repository
The coolant expansion tank contains a silicate repository. Silicate is used to protect the aluminum components in the coolant
system from corrosion. There are silicates in the G13 coolant, but they are used up over time if the engine is subject to high
thermal loads.
To compensate for the silicate consumption, silicate is taken from the repository and added to the coolant. The silicate
repository provides additional protection against corrosion for the aluminum components in the coolant system over the entire
lifespan of the engine.’
Basically "we don't need to change the coolant every 5yrs.. a silica bag does the job of keeping the coolant tip-top"....right up until it splits & FUBARs the entire heating system usually when the car is out of warranty…. :angry:
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This is from a Vw self study
‘ Coolant Expansion Tank with Silicate Repository
The coolant expansion tank contains a silicate repository. Silicate is used to protect the aluminum components in the coolant
system from corrosion. There are silicates in the G13 coolant, but they are used up over time if the engine is subject to high
thermal loads.
To compensate for the silicate consumption, silicate is taken from the repository and added to the coolant. The silicate
repository provides additional protection against corrosion for the aluminum components in the coolant system over the entire
lifespan of the engine.’
Basically "we don't need to change the coolant every 5yrs.. a silica bag does the job of keeping the coolant tip-top"....right up until it splits & FUBARs the entire heating system usually when the car is out of warranty…. :angry:
An excellent summing up of the situation there Dave :grin:
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Hello, first time poster here. Had my car in for a service the other day got a call to say the bag had burst and the coolant was contaminated. They replaced the tank and coolant under warranty car has 30000kms on it 2 years old. Its only a 1 litre just thought some may be interested.
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Interesting thread.
I had read abouts these bags and their failure and was wondering what to do with mine.
As the tanks aren't too expensive I might consider replacing mine rather than trying to squeeze that bag out of the hole and splitting the bag. I've heard these engines are hard to bleed but if I crimp the connecting pipes when I change the tank I should have a problem.......any thoughts?
I'd rather pay for a coolant change every 4 or 5 years than have the hassle of replacing numerous parts when it's out if warranty as I bought the car as a keeper.
Mines a Feb 2019 GTI and it has a bag, not an urgent issue but the previous poster had his fail at just 2 years.
Oddly the wife's 2014 Tdi doesn't have one.
Has anyone on here actually extracted the bag, any tips, other than shown in the video.
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I’m waiting to see if my tank arrives with a bag or without a bag. It’s very exciting!
For the sake of £20 I think I’d just replace the tank rather than try and take the bag out. The videos I’ve seen use long nose pliers and yanking it out and it seems tight.
Knowing my luck I would split the bag !
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I'm in agreement with you, knowing my luck I'd rip the bag too, that space looks really tight.
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.........but, if you’re removing the tank, it’s then easy to remove the bag, without risk, and replace the old tank.
Or am I missing something?
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I was in my local dealer last Saturday picking up a part for my wife’s car,luckily,the parts guy was the nice one who also owns a Golf and is happy to answer any questions you have.
I own a 2015 Golf R so asked him about the coolant bottle and the bag,he said he’s been following the problem closely as he’s concerned about it bursting in his own car.
He showed me a bottle that he ordered in last week for a car that’s coming in this week to have it changed,the bottle was double walled and,when you held it up to the light you could see the bag sandwiched between the walls.Then he shows me another bottle that came in the day before,it was single walled and had no bag.He said this one superseded the first one,and is the only one now available.
It will be interesting to hear what others are being supplied with.
I removed the bag on mine this week,I clamped the bottom hose in case I burst the bag,it honestly took less than ten minutes to remove,as the hose was clamped I didn’t nanny around with it.
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With all this in mind has anyone ever considered waterless coolant in their car?
It has many benefits and you'd obviously do away with the silicate repository.
See here if you've not heard of it before.
https://www.evanscoolant.com/how-it-works/benefits/ (https://www.evanscoolant.com/how-it-works/benefits/)
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.........but, if you’re removing the tank, it’s then easy to remove the bag, without risk, and replace the old tank.
Or am I missing something?
Guess your right...... Probably the safest way to do this job
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I was in my local dealer last Saturday picking up a part for my wife’s car,luckily,the parts guy was the nice one who also owns a Golf and is happy to answer any questions you have.
I own a 2015 Golf R so asked him about the coolant bottle and the bag,he said he’s been following the problem closely as he’s concerned about it bursting in his own car.
He showed me a bottle that he ordered in last week for a car that’s coming in this week to have it changed,the bottle was double walled and,when you held it up to the light you could see the bag sandwiched between the walls.Then he shows me another bottle that came in the day before,it was single walled and had no bag.He said this one superseded the first one,and is the only one now available.
It will be interesting to hear what others are being supplied with.
I removed the bag on mine this week,I clamped the bottom hose in case I burst the bag,it honestly took less than ten minutes to remove,as the hose was clamped I didn’t nanny around with it.
Thanks for the post on how you did it.
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Not sure about this one. VW obviously put the bag in for a good reason.
Mine is 6 1/2 yrs old and has the ‘mit silikat’ label so presumably has the bag of doom.
I have the VW extended warranty so if I did remove it VW would no doubt blame that on any corrosion/failure of the cooling system.
I’m going to leave it as designed by the clever Germans.
If it pops in the near future I’ ll let you all know.
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Not sure about this one. VW obviously put the bag in for a good reason.
Mine is 6 1/2 yrs old and has the ‘mit silikat’ label so presumably has the bag of doom.
I have the VW extended warranty so if I did remove it VW would no doubt blame that on any corrosion/failure of the cooling system.
I’m going to leave it as designed by the clever Germans.
If it pops in the near future I’ ll let you all know.
They designed it to "replenish" the coolant..see a previous post where somebody quoted from the VW mechanics self study guides "ERWIN".....
basically there is NO maintenance schedule on the coolant now & they removed the drain tap that was fitted to previous VWs...so fill for life...
those same clever Germans designed the toothed cam belts on the petrol MQB engines (1lt & 1.4lt etc) to be "for life"...& guess what..now there is a mandatory every 5yr change schedule...
& the extended warranty is only for 5yrs from date of first registration..so yours will be out of warranty...
prevention is better than cure....
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Row Locks.
I have the extended VW warranty. Valid up to 100k.
My better half has just had a new engine (1.4 TSI) after 9 years under this warranty.
Yes the 1.4 twin chargers were very unreliable but at least her car now has a new engine with a 2 yr VW warranty.
It works.
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Row Locks.
I have the extended VW warranty. Valid up to 100k.
My better half has just had a new engine (1.4 TSI) after 9 years under this warranty.
Yes the 1.4 twin chargers were very unreliable but at least her car now has a new engine with a 2 yr VW warranty.
It works.
When I bought my MK7 in 2014 the extended warranty took the factory standard up to a maximum total of 5yrs or 90,000miles whichever occurred sooner...
I know I bought it....I would be very surprised if they changed that in the UK..& you bought your MK7 in 2013...
& those twin charges were replaced due to the well known problems..VWUK did a few engines...
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VW Eos 2008 with 80k on the clock. Full VW service from new. (1.4 TSI 160)
Piston and turbo failure. New engine and turbo under VW extended warranty.
These warranties do work but I’m questioning the logic of removing the bag from the cooling system and then having a claim refused.
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The VW extended warranty is valid up to 100 k for me. Costs approx £ 235 per year.
Mine is July 2013.
I’ll leave the bag in.
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Has anyone thought that the one or two bags that have split might have been faulty? This seems to be going the same way as the pedal box thread, one person gets one and then the rest follow blindly because it must be true. I honestly cannot see the point in replacing an item that's still doing what the manufacturer intended it to do. For a car under three years old to have the bag removed do you expect to get anything replaced under warranty in the case of failure of something else in the coolant system? VW will be waving you away and laughing at the same time. Out of warranty then knock yourselves out.
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Different matter once the car is out of warranty though.
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The question how likely is this to happen? 10 cases per 100,000 cars sold? Tiny risk- ignore it, allow the bag to do its job.
100 cases per 100,000 cars? still wouldn't worry me.
1000 per 100,000?
These forums can create a certain amount of hysteria- a few isolated cases giving the impression of an endemic. I would be interested to hear if anyone has any data on how common this problem is.
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Different matter once the car is out of warranty though.
yes totally agree 👍
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When I was talking to the dealer parts guy last week,he told me,that they have seen quite a few burst,although he didn’t put a number on it.
He also said that they had two cars come in from independent garages,that had the bag burst and the independent changed the heater matrix but,after that they couldn’t get all the silicate flushed out of the system.They had to book it in to the main dealer as,they have a machine specifically for flushing the system out.they hook it up to this and it goes through a process of flushing back flushing.
It does this for a preset time,then all is ok.
As my car is now four years old I decided to remove it.
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When I was talking to the dealer parts guy last week,he told me,that they have seen quite a few burst,although he didn’t put a number on it.
He also said that they had two cars come in from independent garages,that had the bag burst and the independent changed the heater matrix but,after that they couldn’t get all the silicate flushed out of the system.They had to book it in to the main dealer as,they have a machine specifically for flushing the system out.they hook it up to this and it goes through a process of flushing back flushing.
It does this for a preset time,then all is ok.
As my car is now four years old I decided to remove it.
Interesting. If dealers are seeing cases regularly then it might be an issue worth addressing once out of warranty.
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These forums can create a certain amount of hysteria- a few isolated cases giving the impression of an endemic. I would be interested to hear if anyone has any data on how common this problem is.
I'd not call it hysteria.
Over the 5 and a bit years I've been on Golf mk7 forums I've watched carefully for the recurring problems.
Heater matrix at 3+ years is the only thing I've seen appear with any frequency - other than water pumps which seem to fail very often.
The heater matrix getting messed up it now seems people have actually uncovered the cause - until this last week or so I've never seen anyone explain that before.
If I planned to keep my Golf after the end of the warranty period, I'd get the damned tank changed because that is a few quid vs a massive bill for the heater matrix.
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Up until this week Fred I'd never heard of anyone having a heater matrix replaced let alone the possibility of the silica bag bursting!
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Up until this week Fred I'd never heard of anyone having a heater matrix replaced let alone the possibility of the silica bag bursting!
There’s been a few owners over on the Seat Leon forum who’ve had issues with poor warm / hot air output from the car’s heating and ventilation system. Likely cause has been cited as the silica bag bursting and its contents blocking the heater matrix.
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These forums can create a certain amount of hysteria- a few isolated cases giving the impression of an endemic. I would be interested to hear if anyone has any data on how common this problem is.
I'd not call it hysteria.
Over the 5 and a bit years I've been on Golf mk7 forums I've watched carefully for the recurring problems.
Heater matrix at 3+ years is the only thing I've seen appear with any frequency - other than water pumps which seem to fail very often.
The heater matrix getting messed up it now seems people have actually uncovered the cause - until this last week or so I've never seen anyone explain that before.
If I planned to keep my Golf after the end of the warranty period, I'd get the damned tank changed because that is a few quid vs a massive bill for the heater matrix.
I'm not saying it is hysteria- I'm saying it could be, particularly because the consequences of the bag splitting are catastrophic and I bet a good proportion of these get reported on various forums.
Still very little to say how common it is, I am genuinely interested to hear views from garages/dealers as to how often they are seeing these
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Up until this week Fred I'd never heard of anyone having a heater matrix replaced let alone the possibility of the silica bag bursting!
Unfortunately google brings up many cases across various forums dating 2-3 years old.
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Up until this week Fred I'd never heard of anyone having a heater matrix replaced let alone the possibility of the silica bag bursting!
Unfortunately google brings up many cases across various forums dating 2-3 years old.
how many compared to volume sales though?
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These forums can create a certain amount of hysteria- a few isolated cases giving the impression of an endemic. I would be interested to hear if anyone has any data on how common this problem is.
I'd not call it hysteria.
Over the 5 and a bit years I've been on Golf mk7 forums I've watched carefully for the recurring problems.
Heater matrix at 3+ years is the only thing I've seen appear with any frequency - other than water pumps which seem to fail very often.
The heater matrix getting messed up it now seems people have actually uncovered the cause - until this last week or so I've never seen anyone explain that before.
If I planned to keep my Golf after the end of the warranty period, I'd get the damned tank changed because that is a few quid vs a massive bill for the heater matrix.
Totally agree with your comments, whilst mines under warrenty I'll leave it in, the moment its out of warrenty it'll be the first job.
Stupid design IMO, I mean most cooling system changes are at about 5 years, well outside warrenty and well outside having a negative cost effect on lease / servicing deals so why did VW spend time, resources and money fixing a problem that doesn't really exist. Maybe if the G13 is degraded by the car being subjected to high heat thermal loads, by constantly being thrashed by an owner that doesn't give a damn etc then an algorithm in the ECU should be able to compute when it needs changing, just like variable servicing internals on oil. Still I'm sure to VW "seemed a good idea at the time"
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Update
The new tank from VW didn’t contain a bag. So I’ve simply removed my old bag today and shall renew my coolant every 2-3 years from now on.
The bag material is surprisingly strong and thick. My bag was intact.
I can only think the bag rubs against the inside of the tank and eventually splits.
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Update
The new tank from VW didn’t contain a bag. So I’ve simply removed my old bag today and shall renew my coolant every 2-3 years from now on.
The bag material is surprisingly strong and thick. My bag was intact.
I can only think the bag rubs against the inside of the tank and eventually splits.
Do you know the part number of the new tank?
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Update
The new tank from VW didn’t contain a bag. So I’ve simply removed my old bag today and shall renew my coolant every 2-3 years from now on.
The bag material is surprisingly strong and thick. My bag was intact.
I can only think the bag rubs against the inside of the tank and eventually splits.
Do you know the part number of the new tank?
I don’t I’m afraid. Only one part number came up for my car and when I saw the new tank I said to my garage to send it back.
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Do you know the part number of the new tank?
Just take off the old tank, remove the bag, replace the old tank. costs absolutely nothing to do. Absolutely barmy to just buy a new tank without a bag.
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Do you know the part number of the new tank?
Just take off the old tank, remove the bag, replace the old tank. costs absolutely nothing to do. Absolutely barmy to just buy a new tank without a bag.
Exactly right!
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Hello, I was at my local Independent VW specialist today having our other car (Up) serviced and mentioned this to him.
He told me that the had a few cars in with the heater matrix becoming blocked. However, this is not caused by the bag in the tank bursting. Apparently, in his words, there is a scale forms similair to limescale that forms on a kettle and he has seen this in both the matrix and on the bag with the bag remaining intact.
Their fix is to flush the matrix and in the main this is succesful but for some only lasts one year then it needs to be done again. Apparently VW had invested in equipment that is used to flush the matrix that neutralises the contents of the bag but have now withdrawn it as it is not believed to be the culprit.
His advice to me was there is not much you can do to prevent this and to leave the bag alone as there does not seem to be a pattern as to what causes this.
Just to clarify the 2 guys who own the garage are ex main dealer trained mechanics and used to work for Audi and VW and have recent experience within the dealership of this issue.
I hope that helps and doesn't muddy the waters too much.
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Interesting info. Thanks
My 6 year old bag had no limescale on it which is good news I guess.
From the videos I’ve seen, either a bag has split or sand from the manufacturing process of the head has been found in the matrix.
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Is there a VAG Tech on here that can confirm it is only the tanks with a bag that are the potential problem and that the dual wall 'mit silicat' tanks are burst proof so have no danger of clogging the heating system
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He told me that the had a few cars in with the heater matrix becoming blocked. However, this is not caused by the bag in the tank bursting.
Beg to differ on that, the guy that services my car is ex VW and at leat two that have burst he has fixed himself and showed me a bag and matrix that had split. Personally for a few minutes work I would not risk it.