timing belt and water pump replacement - Page 3

SD1too · 20th June 2019, 15:09

Quote:

Originally Posted by trikey

... the noise you hear is the compressor overcharging, turn off your AC until you get the fan repaired or you can damage the compressor

Andy,

Don't forget that in the event of refrigerant pressure rising to an excessive level due to lack of fan assistance, the trinary switch will disengage the compressor clutch which prevents damage.

Simon

Mike Noc · 20th June 2019, 15:51

Has anyone come up with an answer as to the origin of the noise?

All I can think of is it being either a pressure relief valve, or the compressor being driven in reverse by the pressurised refrigerant once the trinary switch disengages the clutch.

The compressor is a Williams Janney style constantly variable positive displacement pump, so if there was enough pressure on the pistons they could be driven back if the swash plate was still at an angle to the block.

20th June 2019, 15:51	#22
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,547 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Has anyone come up with an answer as to the origin of the noise? All I can think of is it being either a pressure relief valve, or the compressor being driven in reverse by the pressurised refrigerant once the trinary switch disengages the clutch. The compressor is a Williams Janney style constantly variable positive displacement pump, so if there was enough pressure on the pistons they could be driven back if the swash plate was still at an angle to the block.