Evening folks. I have an 8v golf mk4 2.0 gti petrol,done 116,000 lately once the old girl is up to temperature put the heater on smells like sweaty socks for 2 minutes but the heater is hotter. Hoping it's not the matrix itself (garage costs would kill the car) or would a cooling system flush cure it? Mostly topped up with coolant but water sometimes.I do have to top the expansion tank up occasionally (who designed the metal cup idea jeez lol) Thank you
if its got aircon the intake might need cleaning out, over time all kinds of nasty stuff gets in and starts growing in there, easy fix. quick google brings up this: https://www.wikihow.com/Eliminate-Odor-from-a-Car-Air-Conditioner while you're there replace the pollen filter, its under the plastic trim around the wipers
cooling flush wont effect the smells in the car , if its not a manky pollen filter then probably the matrix going
It might not be the cause, but clear out all the leaves in the raintray while you're there, VWs seem to collect them like hoovers making everything really damp! I've had some great compost from my Caddy van. This can also avoid water flooding into the interior, creating damp smells.
Thank you for your help, took her for a good run today,smell seems to have gone,but will replace the pollen filter (£4.61 daft not to really) will use mildew/mould spray aswell,thank you Toyotec