Heater blower

[vulcan1208]

The heater blower motor on my 3200 GT is making an annoying droning sound that rises and falls in line with the engine revs, I am guessing I am going to have to replace it and at the same time renew the heater matrix as a precaution, does anyone have an idea of the work involved ? I am not to bothered about the time it takes I am just wondering if it is doable.

 

[Oneball]

There really shouldn’t be much of a link between engine revs and the sound the blower motor makes.

 

[vulcan1208]

There really shouldn’t be much of a link between engine revs and the sound the blower motor makes.

I was thinking it could be a slight increase in voltage as the revs increase, I can't really think of anything else.

 

[Oneball]

I was thinking it could be a slight increase in voltage as the revs increase, I can't really think of anything else.

You could get a slight increase in voltage from idle to say 1200rpm but unless something is wrong with your alternator it won’t increase beyond that.

 

[williamsmix]

If you have the AC engaged it could be noise from the compressor coming through the heater system. If so, try switching the AC off and see if you still get a noise.

 

[vulcan1208]

I have found a couple of "how to" guides on here regarding the heater matrix and fan and will give it a go later this month.

 

[Oneball]

If you take the scuttle trim off you can get to the fan and give it a spin by hand to check it

https://www.sportsmaserati.com/index.php?threads/aircon-clean-out-pollen-filter.222/

 

[vulcan1208]

If you have the AC engaged it could be noise from the compressor coming through the heater system. If so, try switching the AC off and see if you still get a noise.

Thanks for the reply, it does indeed seem to be the AC compressor. Does anyone know how easy it is to change ?

 

[williamsmix]

Thanks for the reply, it does indeed seem to be the AC compressor. Does anyone know how easy it is to change ?

Or possibly regas … if the pressure drops then the compressor could become noisy(?).

 

[Zep]

Or possibly regas … if the pressure drops then the compressor could become noisy(?).

This. But that could also mean partially blocked drier or faulty expansion valve etc etc.

Best get someone who know what they are doing to look at the pressures and temps.

 

[vulcan1208]

The condenser and drier were replaced about 6 months ago with genuine Maserati items, the system blows ice cold its just the noise from the compressor that is annoying.

 

[Zep]

The condenser and drier were replaced about 6 months ago with genuine Maserati items, the system blows ice cold its just the noise from the compressor that is annoying.

What I mean is, the noise could be being generated by the flow of gas, rather than the compressor itself. Bear in mind that the compressor is mounted to the engine and is connected with flexible hoses, so the transfer of vibration is unlikely.