Hello everyone i have a problem with my mk 1 ever since i had a garage change the belts, pump and thermostat 6 months ago. First it was no heat than i managed to get the heat working over 2k rpm after flushing the core. No collant missing at the time. I had a blown heatercore hose last week changed the hoses and the next morning inlet hose clamp came loose and it keeps loosing coolant( regular water now ) on that hose no matter how tight. Not smoking not overheating. Coolant and new thermostat already ordered.

So my guesses so far are:

• Water affecting it since it has 105c thermostat?

• Coolant cap from 1.6 aee wich i think is 1.60 not a 1.40?

• Blown headgasket

• Hetercore( but it shown no pressure on garden hose )

Anyone have any other ideas or confirmation of the ones above?

Originally sounds like either an airlock or blocked heater core and by flushing heater you have cleared it. The fact that the hose is new and still leaking may be that its slightly too large internal diam. Is it a genuine VAG hose or a length of replacement. I have found in the past that the external diameter of aftermarket hoses can be the same as original but the internal diam can be larger. ie thinner hose. Also check for continuous bubbles in expansion tank as if the head gasket has gone it could be pressurizing system and venting coolant out of expansion cap when driving as well as the leak. If the heater core is leaking then you normally notice wet/ damp carpets and car steams up all the time.

Alasdair

15 minutes ago, Alasdair1 said:

Originally sounds like either an airlock or blocked heater core and by flushing heater you have cleared it. The fact that the hose is new and still leaking may be that its slightly too large internal diam. Is it a genuine VAG hose or a length of replacement. I have found in the past that the external diameter of aftermarket hoses can be the same as original but the internal diam can be larger. ie thinner hose. Also check for continuous bubbles in expansion tank as if the head gasket has gone it could be pressurizing system and venting coolant out of expansion cap when driving as well as the leak. If the heater core is leaking then you normally notice wet/ damp carpets and car steams up all the time.

Alasdair

So the water culd not be affecting it?

It shudnt be the wrong diameter i changed the whole set thermotech brand hoses and fittings that go to the heater core. Cabin is dry no bubbles in expansion thank thats whats confusing me. Last night i changed the wormclamps that came with the set to the ones from original hoses and it still leaks a bit. Im thinking of drilling the new thermostat to help with clearing air out is it a bad idia since its ele. controled?

I wouldnt drill thermostat but try squeezing top rad hose with engine running. Squeeze and hold then release and keep repeating. Have had similar airlocks on other vehicles and in my case you eventually get big bubbles in tank. I havent come accross an elec control thermostat but some I believe have heating elements in the body which may be what you mean. I think its for quick warm up icabin temp in cold weather so shouldnt affect low temp. Check the pipe thats leaking for corosion and also if its still round.

Alasdair

1 hour ago, Alasdair1 said:

I wouldnt drill thermostat but try squeezing top rad hose with engine running. Squeeze and hold then release and keep repeating. Have had similar airlocks on other vehicles and in my case you eventually get big bubbles in tank. I havent come accross an elec control thermostat but some I believe have heating elements in the body which may be what you mean. I think its for quick warm up icabin temp in cold weather so shouldnt affect low temp. Check the pipe thats leaking for corosion and also if its still round.

Alasdair

i

1 hour ago, Alasdair1 said:

I wouldnt drill thermostat but try squeezing top rad hose with engine running. Squeeze and hold then release and keep repeating. Have had similar airlocks on other vehicles and in my case you eventually get big bubbles in tank. I havent come accross an elec control thermostat but some I believe have heating elements in the body which may be what you mean. I think its for quick warm up icabin temp in cold weather so shouldnt affect low temp. Check the pipe thats leaking for corosion and also if its still round.

Alasdair

Its getting 1 hole minimum, everything looks good, i changed coolant a lot of times before but this engine is just a nightmare to deal with from electronics to cooling everything has some kind of a problem.

Not sure on your model but on mine MK2 hot air to cabin has a climatronic flap system to mix hot and cold air. The flaps can get worn or stick and cause no heat or no cold air. Think theres a way to reset them which might work if they arent worn out. Sorry don't know on the MK1

Alasdair

It is a manual ac, no heat is not rly an issue as temps rearly go below 0 in the winter now its 30+c and loosing coolant is a problem. If coolant and a termostat dont fix it its going for a headgasket test, if its not that the thermostat is going out.