AC and exhaust heat sheild rattle
14th September 2020
I have recently had two problems with my Golf Mk 7. Both turned out to be easy and cheap to fix.
The first was my car’s AC system no longer appeared to cool the cabin. It was basically just blowing out ambient temperature air. This was accompanied by the fan speed being quite high most of the time. My car has the full, 2-zone digital climate control system and it usually is in “Auto” mode. I just manually tweak the set temperature. Usually the fan speed runs at speed 2 (as indicated by the LED segments in the dial). However, I had noticed that during hot weather days it was running at speed 3 most of the time and yet the temperature of the air coming out of the vents did not really feel that cold. Also, the cabin interior appeared to have quite high humidity. I also noticed hissing noises coming from behind the dash when changing the set temperature.
I have VCDS and so used this to check the HVAC control module for fault codes. It found 3, all to do with actuators sticking: the driver’s side temperature, the passenger’s side temperature and the air recirculation flap. My car has had most of these faults since I acquired the car and fortunately, the climate system works fine the majority of the time. (It does however occasionally switch from blowing cool air to blowing warm air for a second or so. I suspect this is a result of the sticking actuator flaps). I have investigated buying replacement OEM actuators They are not particularly expensive (approximately £100) but fitting them involves taking a lot of the dash out. I decided this was outside of my ability and my local VW dealer suggested it would not be cost effective to let them replace them. So, I have resigned myself to living with the sticking actuators.
However, the AC no longer cooling the cabin I could not ignore so I rang my local independent VW specialist and they agreed to take a look. Fortunately, they reported that it was only the refrigerant level which was low and that a re-gas costing £60 was all that was required. Now the air emitted from the vents is cold again and the climate control fan speed is back down to speed 2. Excellent!
The second problem was a metallic rattle noise upon closing the rear hatch. I thought it was something inside the car, but it turned out to be the heat shield above the rear part of the exhaust. It is a small rectangular sheet of metal immediately above the exhaust's rear silencer located by 4 studs and held in place by a clip pushed onto each stud. All but one of these clips were missing and so the heat shield was, for the most part, resting on the top of the silencer.
Fortunately, 5 replacement (non-OEM) clips were sourced from eBay for just £2.99 including delivery. They just pushed onto the studs and held the heat shield in position. No more rattle!