D4 Aircon Compressor Replacement

[eddielines]

Discovery 4 2010 3.0L TDV6 220K Km

I posted previously but keen to get further feedback with Videos attached

I have a drone / dull whine when car started, not there when I take drive belt off.

As per videos
1. I can get a bit of noise and slight play on the aircon compressor pulley bearing when the belt is off, see first video
2. The noise changes tone and is slightly quieter when the aircon is on, see 2nd video when driving and I turn it on half way through video, my understanding is this confirms its the aircon as it changes due to additional load

I plan on replacing myself

Questions
1. I don't think it can be anything else, as other pulleys are smooth and no noise, but confirmation from those with more knowledge than myself based on videos would be good
2. When I hand turn the clutch / magnetic plate on end of pulley it's smooth, so assume issue is only pulley bearing and internals are good, pulley / bearing can't be replaced on these ? Has to be full unit ?
3. Will take to professional to evacuate refrigerant and regas afterwards, plan on doing this Friday and Monday and replace over weekend, does leaving the condenser without vacuum for this long cause an issue to dryer ?
4. Should I replace condenser also, as car has 220K km even though air con is working ? OEM is Nissen ?
5. OEM for conpressor is Sanden ? I know I should also replace o-rings
6. I know I need to remove fan and shroud, drop coolant, remove wheel and arch, remove coolant tube in front of compressor. Any other tips ?
7. Anything I am missing ?

Thanks in advance, I am learning job by job

[BradC]

Well then. I am chasing the same whine. Just replaced the Alternator because it had a crunchy bearing, but it sounds identical to yours from behind the wheel. I was hoping it was the compressor pulley.

On the 2.7 there's no magnetic clutch. The replacement is relatively straight forward. I've done a few pulley bearings on compressors with mag clutches over the years. Just need the manual for the compressor. Generally they can be done in-place, although I've had to make a tool before to hold the plate while undoing the nose bolt. Figure out how to wind the clutch plate off, then there's usually a circlip behind that holding the pulley in place. The pulley slides off the nose of the compressor. On older units I've replaced the bearing. On the D3 the pulley comes as a unit with the bearing. Don't know for yours.

Bitter experience says if you leave it too long the movement will trash the front bearing in the compressor and take out the seal necessitating replacement, so the earlier you can fix it the cheaper its going to be.

[eddielines]

Thanks, there is magnetic plate on the discovery 4, but think I read it's not serviceable in D4. Would be happy to hear otherwise from the collective wisdom in group.

[eddielines]

Well then. I am chasing the same whine. Just replaced the Alternator because it had a crunchy bearing, but it sounds identical to yours from behind the wheel. I was hoping it was the compressor pulley.

On the 2.7 there's no magnetic clutch. The replacement is relatively straight forward. I've done a few pulley bearings on compressors with mag clutches over the years. Just need the manual for the compressor. Generally they can be done in-place, although I've had to make a tool before to hold the plate while undoing the nose bolt. Figure out how to wind the clutch plate off, then there's usually a circlip behind that holding the pulley in place. The pulley slides off the nose of the compressor. On older units I've replaced the bearing. On the D3 the pulley comes as a unit with the bearing. Don't know for yours.

Bitter experience says if you leave it too long the movement will trash the front bearing in the compressor and take out the seal necessitating replacement, so the earlier you can fix it the cheaper its going to be.

Suggest you take of belt and spin the pulley see whether smooth or noisy.

[BradC]

I did that a couple of weeks ago and everything felt smooth and quiet, which was frustrating.

I did the alternator because even though it felt smooth I knew it was becoming a problem. In the 2 weeks from test to replacement the alternator had become quite crunchy, so I'll have to re-assess the A/C pulley. I have found my mechanics stethoscope, so I'll take the opportunity to have a good listen to all the others while I'm in there.

Thankfully ever since I un-stuck the fan 8 years ago, it always goes back on with grease on the threads and it comes off with a crescent wrench and a gentle tap each time, so I'm getting quite quick at getting the belt on and off.

[DiscoJeffster]

I always thought protocol was to replace the front condenser and dryer anytime you open it up.

[eddielines]

I always thought protocol was to replace the front condenser and dryer anytime you open it up.

Some don't if Compressor hasn't grenades and sent swarf or dust through the System. It depends on how long open for and Vacuuming as soon as possible will remove air moisture from system.

I can get OEM dryer from Rimmers reasonable priced. Anyone any recommendations on the full condenser / dryer unit ?

[eddielines]

Also should rest of system be flushed ? I think I read although some do it, shouldn't flush through the TX.

And if it should be flushed should that be done before or after replacement ?

[eddielines]

I did that a couple of weeks ago and everything felt smooth and quiet, which was frustrating.

I did the alternator because even though it felt smooth I knew it was becoming a problem. In the 2 weeks from test to replacement the alternator had become quite crunchy, so I'll have to re-assess the A/C pulley. I have found my mechanics stethoscope, so I'll take the opportunity to have a good listen to all the others while I'm in there.

Thankfully ever since I un-stuck the fan 8 years ago, it always goes back on with grease on the threads and it comes off with a crescent wrench and a gentle tap each time, so I'm getting quite quick at getting the belt on and off.

With the D3 if you search the Dico UK site you can also bypass the aircon with shorter belt, this will allow you to
1. Verify it is AC
2. Avoid risking damage to wider system until you get it replaced

[PerthDisco]

With the D3 if you search the Dico UK site you can also bypass the aircon with shorter belt, this will allow you to
1. Verify it is AC
2. Avoid risking damage to wider system until you get it replaced

This is very good info as I pondered doing this job DIY. Step 1 would be getting it degassed somewhere then tear it apart in your shed. Then you are a bit stuck in terms of a flush unless you find a mobile specialist. Even driving around with the system reassembled but off is not ideal.

[BradC]

The shorter belt is about $55. Good for an emergency, but a bit expensive as a piece of diagnostic test gear!

I'll wait for a break in the rain and get in there again.

[DiscoJeffster]

The shorter belt is about $55. Good for an emergency, but a bit expensive as a piece of diagnostic test gear!

I'll wait for a break in the rain and get in there again.

Cheaper than a compressor you don't need, but I get your point

[eddielines]

Cheaper than a compressor you don't need, but I get your point

If you need to drive the car its also cheaper than grenading the internals through the whole system which I'd imagine will eventually happen, you'd expect roughness on the pulley bearing even though external will impact internals sooner rather than later. I am getting nervous so will check tomorrow whether that is option for D4 or not while I figure out how to get job done, rather than rushing it.

For D4 visually from above it looks like the compressor it a little too high, but I'll get in back in there tomorrow morning and see if there is a line from bottom of steering pump to bottom of crank pulley avoiding the top of compressor pully.

[eddielines]

This is very good info as I pondered doing this job DIY. Step 1 would be getting it degassed somewhere then tear it apart in your shed. Then you are a bit stuck in terms of a flush unless you find a mobile specialist. Even driving around with the system reassembled but off is not ideal.

Not sure if your a D4, but cost at Just a moment... (https://www.sparesbox.com.au/products/sanden-ac-compressor-12v-direct-mount-pxc16-cxs1694'sid=ddb9ff074a7ae595df998cf5580a2f2a&pos=1) vs 2K at well priced indy, or $3.4K for compressor and condenser all done makes it appealing, but I am time poor so still juggling the options.

I got a Quote for $400 to degas and then come back and regas from mobile guy.

He said best practice is to flush, but I am getting mixed info reading, some saying you shouldn't flush through dryer or TX and that channels are very small in the compressor so while flush may push through you may pack grime / dust tighter in other channels that will dislodge later, and that flush should really just be done after the TX on evaporator and lines between that and pump. The mechanical replacement is supposed to be a pain, but known and with some patience should be ok, still trying to figure out how AC works and what is ok in terms of opening up and what you need to do after.

Seems that if lines capped or not open too long, its not an issue. Also with D4 its got a clutch so I think you can pull the fuse to ensure it doesn't t get turned on while driving to auto shop to get regassed. They should vacuum before degassing, I think this helps boil any any moisture out of the desiccant in the dryer.

In the UK everything rusts but we don't really have that issue her unless living right on cost, so I figure less likely to develop leaks, so replacing condenser in UK is probably a no brainer, but everything more expensive here, so questioning whether I really need to replace the condenser. I am thinking about replacing the Dryer though can get delivered with seals for ~$200 Dryer - JRJ500020P1 - OEM | Rimmer Bros (https://rimmerbros.com/Item--i-JRJ500020P1)

[BradC]

In theory you can't flush the evaporator through the TXV. The condenser is a microchannel unit and is practically impossible to get the residue out of with a flush.

If the compressor has died in a non-"ground to dust" manner then you may get away with it. If you drain the oil from the compressor and it isn't clean (ie has metal residue) then you're going to want to do a flush and replace the condenser.

If the oil is clean, then capping the lines, replacing the dryer and doing a thorough leak test and vacuum before recharging should be ok.

The PAG oil in these systems is incredibly hygroscopic and moisture it absorbs will not be removed by vacuum, only by the dryer. Moisture is the enemy because it hydrolyses the oil back into acid which does "bad things" to the system.