Mk7 no heat from vents plus coolant loss

[vwmk7]

Hi,
I recently took my car to get cambelt+waterpump changed and get my 'no heat from vents' checked
no coolant leak was found external and CO2 test was done and came out green color. no leaks from water pump and both pipes hot from matrix. no error codes from computer
mechanic says coolant is burning internal possible internal blow needs further investigation
I do have warranty but I will have to take it to a different garage so will be doing diagnostics again. Am hoping they find something else as at moment its pointing towards head gasket issue.

cambelt or pump werent changed in the end

This seems like a common issue on these cars , anyone had similar issues?

[SteBrown91]

I think this is normally caused by the silica gel bag bursting then the contents being sucked into the system and causing a blockage- common on the mk7 platform cars

[Dr G]

What does the coolant look like? Bright pink still?

[vwmk7]

Dr G said:

What does the coolant look like? Bright pink still?

Its more like dirty pink. I took the cap off the coolant bottle and it started spilling out. I mustve topped up too much.
Its losing coolant with less than 100 miles driving

[Dr G]

I'm going to bet your heater matrix is all gunked/blocked/corroded.

[vwmk7]

Dr G said:

I'm going to bet your heater matrix is all gunked/blocked/corroded.

I've taken it to couple garages and they refuse to do full diagnosis . Seems like they want to avoid this type of work.
Do you recommend dealer or is indy specialist ok for diagnosis work

[Nemophilist]

Mine clogged up last month. All of a sudden coolant loss and no heat from vents

I’d already removed the silica bag so knew it wasn’t that

The independent I went to said worst case scenario it would need a new heater matrix but luckily they managed to flush it through and clear the blockage.
Took a few goes they said but in the end it worked and only cost half hour labour

[Maxdecel]

Every day's a school day https://www.pistonheads.com/gassing/topic.asp?h=0&... New tech ? That fails out of warranty. Is this to remove changing coolant as a service recommendation to appear green/reduce costs ?

[CarCrazyDad]

vwmk7 said:

Dr G said:

I'm going to bet your heater matrix is all gunked/blocked/corroded.

I've taken it to couple garages and they refuse to do full diagnosis . Seems like they want to avoid this type of work.
Do you recommend dealer or is indy specialist ok for diagnosis work

If you have a warranty -

Why would you not let them deal with it????????

[vwmk7]

CarCrazyDad said:

If you have a warranty -

Why would you not let them deal with it????????

I am going through warranty. The last garage I took it too I informed them it was a warranty job. They checked for leaks, did a pressure test and leakage test and all was OK. They are thinking egr cooler problem. They decided not to diagnose further and recommended I simply go to vw. They didn't charge me either.
I'm simply trying to avoid a run around.
Coolant flush seems like a sensible thing to carry out at this point
Btw its just one of those crappy warranties traders give you with 500 limit and don't even cover the hourly rate

[SteBrown91]

I would forget the warranty and find a good VW specialist, chances are it wouldnt pay out anyway

[vwmk7]

Nemophilist said:

Mine clogged up last month. All of a sudden coolant loss and no heat from vents

I’d already removed the silica bag so knew it wasn’t that

The independent I went to said worst case scenario it would need a new heater matrix but luckily they managed to flush it through and clear the blockage.
Took a few goes they said but in the end it worked and only cost half hour labour

thank you mate. i think this is going to be my next port of call to do a coolant flush. fingers crossed

[Nemophilist]

Did you have any luck sorting yours?

[vwmk7]

Will let you know next week as its booked in for next week.

Did go to one vw specialist and he quoted me almost £800 to change matrix plus the coolant tank. Which I thought was ok after reading online many people getting quoted 1000+.
Until I found out its not that big of a job and got quoted a lot less from another specialist.

[Steve UK]

Hello,

2013 GTD Here.

Same issues last year, coolant loss, gurgling no heat.

Cambelt change, water pump change. For peace of mind I retained the old water pump solenoid and plugged this into the loom rather than the new pump. These pumps have a collar to prevent pumping when cold, the one I removed could have been sticking which would prevent the pump from pumping when hot. Terrible idea, now disabled I cannot see any change in performance or time to reach operating temperature.

Unfortunately the coolant loss gurgling returned soon after.

New heater matrix fitted, do not fit OEM . There is a company in Birmingham which do a nice copper/brass one with larger cores. Now fitted it has been great for over a year, lovely and warm this morning.

All day to fit a matrix is a joke, 2 hours max on my drive!

I believe the matrix partially blocks due to its micro bores and aluminium construction, when the car regens the DPF the cooler for it cannot flow enough coolant hence the local boiling and coolant loss.

Hope this helps, don't get ripped off. All work DIY on my drive. I know it's not possible for most people but it's not specialised work.

[vwmk7]

UPDATE
if anyone is interested or perhaps will help someone else experiencing this problem.

I have had the EGR cooler + heater matrix replaced both genuine parts
mechanic did the flushing 4 times and as well as the bleeding
now the heating is ok and gets warm before temp hits 90.

[Sheepshanks]

Thanks for updating the thread.