Mk1 Golf VR6 - Coolant flow query

[Shaggyjh 1]

Hi all,

I have a 83 Mk1 Golf that has had a Passat VR6 engine conversion. All is coming along ok, apart from i'm now stuck on what to do regarding the coolant system.

I believe the heating systems differ between the Mk1 and the Mk2/Mk3 in that the coolant is always flowing around the system with the later cars, but a flap within the airbox diverts the hotter coolant past the matrix. On the Mk1 there is an inline valve in the cylinder head hose that is controlled to allow coolant through the matrix or not.

At present the previous owner has bypassed the MK1 heater matrix unit and joined the two heater pipes that come from the cylinder head and the auxillary water pump, thus meaning the heater is redundant. I would like it so that i can use it, but properly.

My question is: Does the coolant have to be continuously flowing around the system, will it damage anything if i put the inline valve into the cylinder head hose that goes to the heater matrix? This will obviously block the flow when the valve is closed.

Otherwise i will have to try and do something along the lines of my diagram below, and would it work?

[sleepymike 15]

I thought about this on my mk1 caddy vrt and decided that when the valve to the matrix is closed there looked to be a lack of flow. I added an extra hose just before where the 2 hoses go through the bulkhead and before the valve joining them together so bypassing the heater matrix and valve if the valve was closed/ in the cold position.

[Shaggyjh 1]

Hi mate, have you got a picture if possible? I guess it looks like my diagram I drew on paint does it?

[sleepymike 15]

Yeah I'll get one in a bit.