Noisy Heater Blower

[muttontop]

Hi, can anyone help, during the recent hot weather when I started up my C5 after it had been left out in the sun and the cabin was very hot, the climate control was set to the lowest setting and when it cut in, the heater blower motor started and then suddenly developed a much louder sound as though something was lodged in the ducting. This has continued since then but only when the climate control is working at low temperatures with the need for full airflow. Anybody any ideas?

[paul.h]

I would check in the car handbook, it may be it is designed to automatically go onto recirculation when on full to cool the car quickly and is therefore working normally.

[Randombloke]

This has continued since then but only when the climate control is working at low temperatures with the need for full airflow. Anybody any ideas?

 

Check if the display for the fan when it's on auto shows the fan as working flat out. If so, no worries, it's very noisy. If the fan is not at full speed (that is, not all fans segments dark in the LCD display) then maybe a flap is jamming.

[muttontop]

Hi Paul

Thanks for the suggestion. Checked in handbook, there is no mention of the air conditioning automatically going to air recirculation mode, the car has the automatic climate control type air conditioning. Another thing I noticed today was that the fan speed cycled quickly slightly up and down whilst I was driving. The handbook mentions that the external air intake grill and the grill manifold located at the base of the windscreen should be kept clear of obstructions, external grill appears clear but it looks like the grill manifold could be hidden underneath the scuttle grill and this looks fairly complex to remove (windscreen wipers, etc), how easy is this to remove to check the grill manifold?

 

Hi Randombloke

Fan was not operating at full volume, one segment short, would a jamming flap cause a cyclic increase/decrease in fan motor speed? If it is a jamming flap whereabouts are they and are they easy to reach to free?

 

Thanks

[Randombloke]

Fan was not operating at full volume, one segment short, would a jamming flap cause a cyclic increase/decrease in fan motor speed? If it is a jamming flap whereabouts are they and are they easy to reach to free?

 

That's pretty close to full. Some times you will find that as well as turning the fan up or down the climate control also changes where the air is directed as part of its control mechanism.

 

The flaps aren't easy to reach IMV but there is a full guide posted somewhere on this forum about how to access them. It was posted with regard to a problem with excessive heat on the passenger side when the air con was at minimum temperature.

[paul.h]

Unless you need to remove the scuttle for something such as a wet footwell (a search on this gives more info and fixing), I would leave it alone since it may start such leaks (my experience, first noticed after fitting wiring for a towbar). The air intake under the scuttle is like a box section clipped to the bulkhead with a grill at the front that slopes at about 45° facing up - I can not imagine anything getting through the scuttle and to this grill and blocking it. The Haynes manual covers scuttle removal for access to the wiper motor and has pictures and I could also e-mail ones from when I sorted leaks on mine.

 

To see if it does go on to recycle you may detect a change in the air flow sucked in from the outside by placing a hand over the grill area.