AC issues

[RalphyBMW]

Just looking for a steer, as my AC appears to have stopped working.

I guess the first step should be a leak test by the local garage, but before that I figured I’d ask for advice.

2021, cars been laid up, A/C doesn’t work, replace condensers, regas, all good.

2022, advised of I think it was corrosion or some issue with one of the under car pipes, had that replaced, regas, all good.

2023, I’ve got a few “damp” spots on each condenser, which were mentioned at the service. Now it’s warmer I can tell that the AC doesn’t seem to do much other than pop the fans on.

Would a few damp patches typically indicate leaks?

Should I replace the dryer too?

What do folks do about the plastic trims on the condensers? On the current EIS items a carefully modified to accept them, but I’d prefer not to need to do this.

TIA!

[½cwt]

Get a leak test done first.  Could be duff seals in the compressor if the other parts you mention have been changed.

[RalphyBMW]

Cheers, I’ll get it booked in asap.

[Codfanglers]

If the cooling fans are coming on and the compressor clutch engages, there is still some pressure in the system. Check your damp patches and lines with one of these to see where/if you are losing refrigerant. 

Car And A/C Fluid Leaks Uv Detection 9 LED Torch - FREE BATTERIES | eBay

[Menoporsche]

As an aside, do you have grilles in front of the condensors? They can reduce stone damage and also leaves building up leading to rot (do NOT underestimate how much cr*p can accumulate out of sight between condensor and radiator).

[RalphyBMW]

23 minutes ago, Menoporsche said:

As an aside, do you have grilles in front of the condensors? They can reduce stone damage and also leaves building up leading to rot (do NOT underestimate how much cr*p can accumulate out of sight between condensor and radiator).

I don’t yet, but this is my plan when I take the bumper off.

Given it’s only just over 2 years since I cleared it all out, car lives inside, most use in the summer, etc. I was quite surprised at how much crud I can see already just through the grills.

Planning to get some black mesh and fix it in place behind the OE grills, not a huge fan of the Zund Sport items, they’re a bit too prominent for my liking.

I need to get the front bumper painted, had planned on doing this at the same time, but suspect the condenser issue is more urgent, so however I fix the mesh will need to be removable.

[½cwt]

I fitted the mesh to my grilles, so on a 2.7 they will be removable, centre one on my S can easily be popped off, only fitted with a hot glue gun.

 

 

 

[Codfanglers]

I would doubt you have collected enough crud to rot new condensers out after two years.

ATS will vac out your refrigerant and recharge your aircon and check it's working for £36 with the Groupon voucher. They won't (can't) replace the refrigerant though if they find it leaks and will leave the system empty (you can then get a refund or recharge when repaired), but at least you'll know if you have a serious leak. 

In reality, it will be an uphill battle keeping a 20 year-old A/C system completely gas tight and I'd consider a £36 recharge every year or two would be acceptable.

Edited June 4, 2023 by Codfanglers

[RalphyBMW]

4 hours ago, ½cwt said:

I fitted the mesh to my grilles, so on a 2.7 they will be removable, centre one on my S can easily be popped off, only fitted with a hot glue gun.

 

 

 

That shows me what I needed to see, thanks.

Ordered some mesh, trying to pin down some spare grills.

[RalphyBMW]

1 hour ago, Codfanglers said:

I would doubt you have collected enough crud to rot new condensers out after two years.

ATS will vac out your refrigerant and recharge your aircon and check it's working for £36 with the Groupon voucher. They won't (can't) replace the refrigerant though if they find it leaks and will leave the system empty (you can then get a refund or recharge when repaired), but at least you'll know if you have a serious leak. 

In reality, it will be an uphill battle keeping a 20 year-old A/C system completely gas tight and I'd consider a £36 recharge every year or two would be acceptable.

Cheers, there’s a garage I can walk home from who can look into it for me.

Don’t disagree on the “reasonable cost” bit, just frustrating at the additional spend over the past few years and the disruption of getting it sorted, again.

When Revolution serviced the car they mentioned that there may be leaks - but these damp spots appear more likely from stone damage than corrosion.

We’ve also got a 10 year old MINI that needs a new condenser (AC works but not when it’s really hot - condenser has lost maybe 40% of its fins but still holds pressure) so out of 4 cars in the household, only 2 have properly functioning AC.

On the plus side, will build the relationship with our local garage!

Edited June 4, 2023 by RalphyBMW

[RalphyBMW]

On 6/4/2023 at 8:41 AM, Codfanglers said:

If the cooling fans are coming on and the compressor clutch engages, there is still some pressure in the system. Check your damp patches and lines with one of these to see where/if you are losing refrigerant. 

Car And A/C Fluid Leaks Uv Detection 9 LED Torch - FREE BATTERIES | eBay

Bought one of these, very useful, thanks.

Identified some spots on both front condensers.

Took the car to the garage, they checked and confirmed.

Pair of new condensers and a dryer arrived today.

Some fine mesh arrived earlier this week.

Looks like I’ll be spending an evening taking the front end to bits and swapping over.

I’ve not looked at the Mahle condensers yet, but what do people do when there aren’t the holes for the upper & lower trims?

[½cwt]

7 minutes ago, RalphyBMW said:

Bought one of these, very useful, thanks.

Identified some spots on both front condensers.

Took the car to the garage, they checked and confirmed.

Pair of new condensers and a dryer arrived today.

Some fine mesh arrived earlier this week.

Looks like I’ll be spending an evening taking the front end to bits and swapping over.

I’ve not looked at the Mahle condensers yet, but what do people do when there aren’t the holes for the upper & lower trims?

Maybe take the opportunity to switch the bumper retaining screws to stainless steel.

[RalphyBMW]

12 minutes ago, ½cwt said:

Maybe take the opportunity to switch the bumper retaining screws to stainless steel.

I think I replaced a lot back in 2021, but not with SS, just OE.

Got a link to SS?

[fizz]

Since we are on the topic of AC condensers... having had my bumper off couple of weeks back this was the state of mine. 

So I'm still learning this home DIY mechanic stuff so time for a silly question.

The fins I understand help to increase surface area to help the heat transfer out? 

The fins are buggered on mine but my question is where does the gas/fluid travel through the rad? Does it go through the horizontal flat strips in between the fins or just round the outer frame of it? 

As my AC is dead and I presume is fully leaked out after the last recharge I did over a year ago, is the replacement a simple swap over I can do myself? 

[RalphyBMW]

The gas travels through the blades, the fins just to increase surface area.

Our MINI has lost about 1/3 of its fins, but still works, only less effectively.

Replacement is pretty straightforward but you do need to have some refrigerant to lubricate the new O rings, beyond that it’s pretty much bolt off, bolt on, then get a regas somewhere local.

Couple of points to note - if your AC still works, there will be refrigerant in the system, this should be removed before undoing any connections.

There may be other issues in your system (pipework, dessicator, compressor) that may also be leaking.

The factory condensers have plastic trims top & bottom, aftermarket don’t have the holes for these.

Some say you should replace the dessicator too - I’m going to this time.

I just picked up new Mahle condensers and dessicator from Autodoc for £142 delivered.

You need new O rings, I’m waiting for my local OPC to come back with a price, probably ~£5 each.

[fizz]

12 minutes ago, RalphyBMW said:

Couple of points to note - if your AC still works, there will be refrigerant in the system, this should be removed before undoing any connections.

Totally dead... the ac pump engages as the speed of the fan changes when the button is pressed but zero cooling air. 

When I did get it recharged before it lasted for about 3 to 4 months or so. I'm presuming that would indicate a leak and going by the state of my condensors I'd get them changed first. 

14 minutes ago, RalphyBMW said:

The gas travels through the blades, the fins just to increase surface area.

Pretty much what I thought. 👍

15 minutes ago, RalphyBMW said:

The factory condensers have plastic trims top & bottom, aftermarket don’t have the holes for these.

Yup I saw them when cleaning out the rads.ĺ

 

16 minutes ago, RalphyBMW said:

Some say you should replace the dessicator too - I’m going to this time.

What's the dessicator? 

[RalphyBMW]

Dessicator = dryer

Small cylindrical unit I believe lives under the scuttle trim, near the battery.

[RalphyBMW]

These are what I’ve ordered this time;

Dessicator

https://m.autodoc.co.uk/mahle-original/15288270

Condensers

https://m.autodoc.co.uk/mahle-original/15285891

If you look at Autodoc then note the discount changed each day, 41% is a good result.

I used EIS from ECP last time, they’ve now died, hoping Mahle + some mesh will help these last longer.

[Codfanglers]

22 hours ago, fizz said:

Totally dead... the ac pump engages as the speed of the fan changes when the button is pressed but zero cooling air. 

 

 

There is a pressure switch in the system to protect the compressor by stopping the clutch engaging if the pressure drops too low so there is probably still "some" refrigerant in there. 

[MikeT999]

Regarding the seals, I bought this selection box from CoolPartsUK on ebay...

https://www.ebay.co.uk/itm/283015067060

Worked out cheaper than from Porsche as I was doing the long pipes under the sill as well as the condensors.

Hth

Mike.