456 A/C Problem

Now this is an issue that has been bothering me for some time. Here is the timeline:

August '12, bought car and recharged ac system as it was just blowing warm air. After that it seemed fine but I was going into fall here in Alberta Canada so it was cooling down going into fall.

April '13, got. Out of storage and it just blew warm air. Recharged at my work (Lexus dealer) and it seemed ok at best, just never enough.......and I'm in Canada. This would not be acceptable in the southern states. If the car is in my garage all night and then I drive, it seems ok. But if the car has been sitting outside in warm weather, then it is crap.

I took it to the Ferrari dealer and all they do was top it up (again) and told me that was they it is. And they couldn't find a leak.

There has to be something wrong.........has anyone else had this. This can't be the way it is as it would be absolutely useless anywhere hot and humid. This is my only real grievance with this car. I see ads for rebuilt compressors, were the a culprit.

Any help would be appreciated,
Scott
'95 456 GT

 

The best thing to do is to recover the gas, put the CORRECT amount of gas in and see if the a/c is 100%.

If it is, then there are no issues with the system with the exception of a small leak. If you are getting 12 months out of it before it stops blowing cold air, then it's considered a small leak.

That's what I would do first. Depending on the compressor, most cars require the correct amount of gas in the system to work properly.

If you know the system is working properly with the right amount of gas in it, then you will know next time to try and find the leak when it goes warm again.

Sometimes it's hard to find those small leaks, you normally don't have much luck until the leak get's 'worse'.

I have worked on many cars over the years with very small leaks that I just can't find. It really annoys the **** out of you when you come across it.

Recover what's in there now, put the right amount of charge in it and let us know how you go please Scott.

 

Pap, Scott- Putting in a new dryer/receiver/filter might help, too.

 

Thanks for the replies, whats frustrating is like what I said before.....that If the car is in my garage all night and then I drive, it seems ok (just ok too). But if the car has been sitting outside in warm weather, then it blows warm. Even right after it has been recharged.

I could even live with recharging it up every year, but it just doesn't work to the extent I would like to anytime.

Scott

 

Have you tried to reset the ECU? I.e. power cycle the car with the master switch at the battery. I had a similiar effect on my 456M. After ECU reset everything was fine.

Just let it sit 10min or more with power off. All ECUs forget their data. Be carefull with restart, as there is a routine for learning in the engine ECUs. Just let it idle for several minutes.

The exact procedure is somwhere in this forum - I just can not find it now using the little screen of the iphone.

 

I'll try that tonight, ansd see what happens. I will advise.................

Thanks
Scott

 

So I guess the service dept. already put dye in and still couldn't find the leak under uv light?

 

Dye was in it, but could not find it as they say. But they did not remove underpanels to look, That was one thing I was going to do with the uv light.

Good point to bring up though......

 

First prob was needed charge equals leak. Second prob is even when charged it is not cold enough.


I would check wsm it lists specs like output air temp at what ambient temp. And it lists high and low side pressures under certaiin operating conditions. So you got a leak and you got poor function. Find leak with a halogen detector . Use a/c gaauges to spec out the system running. Results of gauges will lead you to answer of why poor performance. Best practices might include other replacement items as taz suggests like reciever dryer.

 

Absolutely, once the issue is known and sorted then fit a new dryer before you charge it back up.

All good mate, but do you know if it has a leak????

It might be leaking out as soon as it has a full charge. That indicates that it has a decent leak and should be easy to find.

You can use the dye trick, but I have A LOT of success putting in nitrogen and hearing/finding the leak that way.

Again, if you can't hear or see a leak anywhere then it's obviously a slow leak and they can be hard to find most times until they become more apparent.

To be 100% sure, I would recover the gas, put the correct amount into it then see how the a/c performs. If the a/c is ice cold straight after the correct charge has been put into it then Scott then you know it has a leak.

If the a/c system is still crap after the correct charge has been put back into it, then you know you have an issue.

If you have an issue, then it's a whole other ball game then.

Listen to the expert- ME!

Recover the gas, fill with the CORRECT amount and test the a/c then mate. The a/c has been topped up so many times it seems that who knows how much a/c charge is in there.

 

After it was at the dealer this year, the recovered what was left and put in the proper charge. They said it was left on the machine for 20 hours or so and no leak was detected. But at that time it also was not run. After it was disconnected, and I picked it up, it was still not up to effect I would expect.

The biggest thing I find is that if it has been sitting inside, and I take it out it blows adequate. BUT if it has been sitting outside (say if I take it to work), it blow warm and that is it.

I think I might have multiple issues here, I will take a look at a few things this weekend, and report back on my results.

I appreciate all the feedback.

Scott

 

Hi Scott,

Ok, it sounds like it has the right amount in there. (Here's hoping they know how much to put in there. )

While you are doing some checks, be sure to check and see if the condenser fans are working. They should come on with the a/c.

Let us know how you go mate. Take care and enjoy the weekend.

 

As per your check, no fans come on when a/c is turned on. I took the car for a good drive and when I heard the fan kick on, I pulled over and it was only the RH fan blowing. The LH fan was not working at all.

So I got home and double checked, and came up with the same results. Now I haven't done anything else, I wanted to wait till the car cooled down (and my garage as that engine gives off a lot of heat).

Will post my further findings later.

Scott

 

Cool Scott, you might be onto something.

 

Sort him out yet Scott?

 

Well........I had a week off and planned to get around to it, but my wife's idea of me having a week off was different than mine, so it filled up quickly. As a result, not much Fcar repair time.

As I had previously taken it to the dealer and they were bit baffled, I was frustrated a little so I posted on here. Our dealer is new here so they are more intuned to the newer stuff, they will not have the experience in the 456/550 cars as a dealer that has been opened for along time, but I do really like them and get along with them.

I work at a car dealership, and right near me is the Aston Martin/Bentley/Spyker dealer and they have a tech that handles all their exotics. Guys in my club speak very highly of him so I went over and chatted with him about my issue, he thought about it and came up with a couple things right away. He mentioned a problem that sometimes arise between the temp door, but could also be in a another flap. I'm going to recharge again just so I know it is topped up here at work, take my cover off below and scan with a UV light and see if there is no leaks. If that is correct, he will look at it for me.

As far as my LH fan not coming on, that is still an issue. When I have the cover off, I will check for power at the connection, and apply power to the fan to see if it works. It will be much easier to get at from below than it is from up top.

Soooooo, that is where I'm at!

Scott

 

Cool Scott, be sure to let us know how you go.

 

[
Soooooo, that is where I'm at!

Scott[/QUOTE]

Scott,
There's also a mixing valve that lets a predetermined amount of coolent thru the heater to mix with the a/c. My car would only blow cool air not cold. The valve is on the right side of the battery (looking at the car from the front). I took mine out and opened it up to find the valve was stuck. I freed the valve up and since then the air blows cold!

 

Scott,
There's also a mixing valve that lets a predetermined amount of coolent thru the heater to mix with the a/c. My car would only blow cool air not cold. The valve is on the right side of the battery (looking at the car from the front). I took mine out and opened it up to find the valve was stuck. I freed the valve up and since then the air blows cold![/QUOTE]

Thanks for the tip, I will take a look at that.

Scott

 

Scott,
There's also a mixing valve that lets a predetermined amount of coolent thru the heater to mix with the a/c. My car would only blow cool air not cold. The valve is on the right side of the battery (looking at the car from the front). I took mine out and opened it up to find the valve was stuck. I freed the valve up and since then the air blows cold![/QUOTE]

Did you drain your coolant when you did this?

Scott

 

Hey, just found this one on my HD. Perhaps that Diavia ECU is the problem:
View attachment Diavia AC System.pdf

 

Mehl

Can you tell me where you find these technical bulletins online? I have a 456 and have obviously saved this bulletin to a "technical folder" on my Mac.

Thanks

AK

 

Sorry I don't remember where I've found this one. I guess I found quite a lot on ferraridatabase.com. However the most documents were collected from the ferrari forums like this one. I have my 456 for 6 years and before I was searching 3 years. Thats 9 years of collecting all information I can get.

 

Did you drain your coolant when you did this?

Scott[/QUOTE]

No Scott,
The unit is high enough in the cooling system the draining the header tank is all you really need.

Rick . . . .

 

I do have a question for anyone out there than can answer it for me. When you first start your car, and then turn on your A/C, does a fan kick on right away? And which one is it?

Thanks,
Scott