Coolant leak

[prn31]

So almost a year and 15,000km on and after numerous top ups of coolant I’ve just had the water pump replaced again under warranty…

Apparently the water pump that failed was a “revised”version. The service advisor at the VW dealership showed me the old pump and it was leaking from the same area that most of them do. Car is out of warranty in December but I have two years warranty on the water pump. I asked how much it would cost to do this as a paid job and was told around $1,400. Apparently they do a water pump replacement on the Mk7 every day!

They did throw in a complimentary bottle of the factory coolant concentrate…

[flat6]

My 16R has been low on coolant lately, advised them of this at the last service, turns out the thermostat housing has to be replaced under warranty, known fault with MY16 models

[prn31]

My 16R has been low on coolant lately, advised them of this at the last service, turns out the thermostat housing has to be replaced under warranty, known fault with MY16 models

My understanding is that the water pump assembly includes the thermostat housing and is replaced as one complete unit. The service advisor who showed me my pump says it can leak from three different areas but the most common was the thermostat housing where ours was leaking from.

This water pump is used in the 110 TSI as well as the GTI and R, but most failures are in the GTI and R engines.

It’s a worry that the revised water pump design doesn’t appear to have solved the problem….

[brad]

My understanding is that the water pump assembly includes the thermostat housing and is replaced as one complete unit. The service advisor who showed me my pump says it can leak from three different areas but the most common was the thermostat housing where ours was leaking from.

This water pump is used in the 110 TSI as well as the GTI and R, but most failures are in the GTI and R engines.

It’s a worry that the revised water pump design doesn’t appear to have solved the problem….

You can buy the water pump as a separate unit but it's good practice to replace the housing (which includes a thermostat and a sensor) as well.
I did mine (water pump O-ring leak) way back in 2012 and it was ~$1400 back then (~$800 in parts) at an independent. It went again in Jan 2017 due to a cracked housing (you must use a torque wrench on them as they are fragile. The bolt torque is about 10Nm) and it cost me $125 for the full assembly. It took 2 hours to remove and 3 hours to assemble. I removed all the carbon from the intakes at the same time which was another days work.
It's not that hard a job in terms of difficulty - just fiddly.

[vwMK7coolantLEAK]

My 2013 VW Golf begun leaking coolant in April 2019. Coolant light came on, so I bought some G13 coolant and topped it up but within a short time the coolant light had come back on and I took it to the car repairers for a fix. At first, the water pump was found to be the culprit and I got the water pump, thermostat and thermostat housing replaced with genuine VW parts. I had to wait for a few weeks until all the parts arrived because they were sourced from VW and the toothed belt housing (which seems to be the issue causing all these coolant leaks) was replaced also. From what I understand, VW is still replacing the defective housing with the original, plastic designs. I strongly urge you to ensure that this housing is not repaired by VW.

It only took a month and the light was back on. On second inspection, the repairers were unable to find a cause of the coolant leak and were aware that there were other VW customers who were confused about their own heat exchangers leaking internally. Since my coolant was leaking at such a rapid pace, it would only hold a full tank for about 12 hours. Consequently, the engine light came on and it repeatedly overheated. Throughout this whole repair process, I was unable to find any comprehensive explanation online to gain a better understanding of what I should do about my problem. I have written this post in goodwill to assist with any future concerns that VW mk7 vehicle owners might have regarding their coolant leaking.

I took the car to the manufacturer later in the year and paid $250 for a diagnosis which read “low compression/defective water pump” as the cause. As mentioned above, I had this replaced earlier in the year. I came in to collect the vehicle and I asked to see the mechanics. When I came into the workshop, I was immediately handed a piece of plastic and told “this is your problem” by one of the guys. Consequentially, the internal damage due to overheating of the engine would make further repairs somewhat futile for me if engine failure was an inevitable likelihood.

That melted plastic (pictured) was left out of the diagnosis report but handed to me as the first finding by the mechanic. I kindly asked the VW service centre to include this as a finding on the report provided to me. I waited over two weeks whilst they told me they were amending the diagnosis report – but in the end I was told that they were unable to include the finding. Screenshots of their emails admitting about it are linked below. The discrepancy between my diagnosis report and email correspondence suggests that VW is not being honest about this design flaw and seems to be purposely misleading their mk7 owners about the melting plastic casing.

As you may not already know, the new mk7.5 range has now used steel casing rather than plastic to avoid this issue. If I had known about the melting plastic sooner than I would have been able to identify the problem and have it replaced with a suitable material (i.e. steel casing rather than plastic). I hope I can show the online community concerned about coolant leaks that there is most likely an issue with melting plastic around the coolant tank, specifically encasing the “toothed belt”.

Diagnosis report: Pasteboard - Uploaded Image
Email correspondence: Pasteboard - Uploaded Image
Melted plastic casing top-side: Pasteboard - Uploaded Image
Melted plastic casing bottom-side: Pasteboard - Uploaded Image

[vwMK7coolantLEAK]

My 2013 VW Golf begun leaking coolant in April 2019. Coolant light came on, so I bought some G13 coolant and topped it up but within a short time the coolant light had come back on and I took it to the car repairers for a fix. At first, the water pump was found to be the culprit and I got the water pump, thermostat and thermostat housing replaced with genuine VW parts. I had to wait for a few weeks until all the parts arrived because they were sourced from VW and the toothed belt housing (which seems to be the issue causing all these coolant leaks) was replaced also. From what I understand, VW is still replacing the defective housing with the original, plastic designs. I strongly urge you to ensure that this housing is not repaired by VW.

It only took a month and the light was back on. On second inspection, the repairers were unable to find a cause of the coolant leak and were aware that there were other VW customers who were confused about their own heat exchangers leaking internally. Since my coolant was leaking at such a rapid pace, it would only hold a full tank for about 12 hours. Consequently, the engine light came on and it repeatedly overheated. Throughout this whole repair process, I was unable to find any comprehensive explanation online to gain a better understanding of what I should do about my problem. I have written this post in goodwill to assist with any future concerns that VW mk7 vehicle owners might have regarding their coolant leaking.

I took the car to the manufacturer later in the year and paid $250 for a diagnosis which read “low compression/defective water pump” as the cause. As mentioned above, I had this replaced earlier in the year. I came in to collect the vehicle and I asked to see the mechanics. When I came into the workshop, I was immediately handed a piece of plastic and told “this is your problem” by one of the guys. Consequentially, the internal damage due to overheating of the engine would make further repairs somewhat futile for me if engine failure was an inevitable likelihood.

That melted plastic (pictured) was left out of the diagnosis report but handed to me as the first finding by the mechanic. I kindly asked the VW service centre to include this as a finding on the report provided to me. I waited over two weeks whilst they told me they were amending the diagnosis report – but in the end I was told that they were unable to include the finding. Screenshots of their emails admitting about it are linked below. The discrepancy between my diagnosis report and email correspondence suggests that VW is not being honest about this design flaw and seems to be purposely misleading their mk7 owners about the melting plastic casing.

As you may not already know, the new mk7.5 range has now used steel casing rather than plastic to avoid this issue. If I had known about the melting plastic sooner than I would have been able to identify the problem and have it replaced with a suitable material (i.e. steel casing rather than plastic). I hope I can show the online community concerned about coolant leaks that there is most likely an issue with melting plastic around the coolant tank, specifically encasing the “toothed belt”.

Diagnosis report:


Email correspondence:


Melted plastic casing top-side:


Melted plastic casing bottom-side:

[clio]

The water pumps are poor components. I'm just gearing up to replace mine (Mk7 GTI).

[brad]

The water pumps are poor components. I'm just gearing up to replace mine (Mk7 GTI).

1.4tsi water pump is in a totally different spot to a GTI.

BTW: I'm told the EA888 water pump can be done without removing the manifold if you know what you are doing.
I've done it by removing the manifold. It's not a hard job.