P38A Intermittent aircon problem.

hi folks. I had a new air on pump fitted with new seals earlier this year and it worked fine that is until this hot weather arrived. I have noticed that the book symbol appears when the car is warmed from the sun usually above 20 degrees or so. I am certain the aircon doesn't seem to work. The pump fires up when the button is pressed i.e. There is a noticeable engine revs change but nothing seems to get thru. Until the weather cools down I won't know if it's still airconning. Is it a blend motor? The pollen filters seem to be ok. Anyone any ideas.

If you push in the aircon button it switches the aircon off I believe. My book symbol comes on after about 5 mins, I have a sticky blend motor but the aircon still works. Have you had the gas checked lately?

Lack of gas will cause poor cooling get the level checked. Low gas will not bring up the book sign. When lamp is lit on aircon switch, aircon is off.

If you don't have diagnostics, I'm not far away. I'm often out of the country but could look at the fault codes as and when I'm available.
I suspect that even if the clutch isn't pulling in, the revs will still change slightly as there is demand for the aircon so the engine ecu ups the idle slightly.
You need to look at the pulley and see if it is physically pulling the clutch in. If it is and there's gas in it, the pipes should very quickly start to cool and you should feel a marked difference between the temp of the inlet and outlet pipe at the pump.

Cheers folks. The system was fully checked when I had a fully recon pump fitted this year. I do realise that when the light above the switch is on the system is off.
Thing is this morning it was fine. The book symbol is still on too. Mind boggling.

Wazzajnr said:

If you don't have diagnostics, I'm not far away. I'm often out of the country but could look at the fault codes as and when I'm available.
I suspect that even if the clutch isn't pulling in, the revs will still change slightly as there is demand for the aircon so the engine ecu ups the idle slightly.
You need to look at the pulley and see if it is physically pulling the clutch in. If it is and there's gas in it, the pipes should very quickly start to cool and you should feel a marked difference between the temp of the inlet and outlet pipe at the pump.

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I'll take you up on that sir. When may you be available?

blackburnbertie said:

Cheers folks. The system was fully checked when I had a fully recon pump fitted this year. I do realise that when the light above the switch is on the system is off.
Thing is this morning it was fine. The book symbol is still on too. Mind boggling.


I'll take you up on that sir. When may you be available?

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I'm in berlin from tomorrow and back Thursday or Friday evening depending how the job goes.
I should be OK for Saturday morning if that suits? After that I'll be away for a couple of weeks in the states and Italy.

When was the condenser last replaced?

wammers said:

Lack of gas will cause poor cooling get the level checked. Low gas will not bring up the book sign. When lamp is lit on aircon switch, aircon is off.

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I'm pretty sure the levels are fine, I only got the whole system overhauled this year.

Grrrrrr said:

When was the condenser last replaced?

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Two years ago. A recon one. It's a bit of a saga this, I went for a refill and found the condenser was leaking so a second hand one was slapped on. Fired it up only to find the belt had been removed prior to me buying the car. Turned out the pump was screwed. Tried two off eBay, yes I know you pay your price and you get what you pay for. Eventually I went for a fully recon pump, new seals, everything. I honestly think the blend motors are to blame. Funny thing is it's been fine today

Wazzajnr said:

I'm in berlin from tomorrow and back Thursday or Friday evening depending how the job goes.
I should be OK for Saturday morning if that suits? After that I'll be away for a couple of weeks in the states and Italy.

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Oh poo, I'm away until Sunday. I can always nip into graham crooks in hoghton, unless of course you're graham crook

cornishboater said:

If you push in the aircon button it switches the aircon off I believe. My book symbol comes on after about 5 mins, I have a sticky blend motor but the aircon still works. Have you had the gas checked lately?

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All regassed when I had it overhauled. Queer thing is when I put it on say 16 degrees and on auto it seems fine.

blackburnbertie said:

Oh poo, I'm away until Sunday. I can always nip into graham crooks in hoghton, unless of course you're graham crook

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No, not Graham crook. Does he have P38 specific diagnostic? If not, he won't be much help I'm afraid.
Following Saturday I should be home but you'd have to come to mine as I'm only home for 24 hours so I'll need to spend maximum time with SWMBO

blackburnbertie said:

All regassed when I had it overhauled. Queer thing is when I put it on say 16 degrees and on auto it seems fine.

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Every so often I put it on LOW for 5 minutes then HIGH for 5 minutes then back to LOW one last time and then back to its normal temperature. Never take it off AUTO. Seems to keep my flaps free in the breeze.

My wee book comes on sometimes, I'm guessing blend motors. Mostly, everything works hunky dory, but that book does what it wants!

Always have freezing AC though, new condenser last year and regas. Perfect so far....

Doo said:

My wee book comes on sometimes, I'm guessing blend motors. Mostly, everything works hunky dory, but that book does what it wants!
Always have freezing AC though, new condenser last year and regas. Perfect so far....

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My book randomly comes on and it's the coolant temp sensor. Common failure apparently and will be replaced if or more likely when I replace the heater matrix with an Audi one.
Doesn't seem to affect operation in any way so kinda wonder what's the point of it!

Wazzajnr said:

My book randomly comes on and it's the coolant temp sensor. Common failure apparently and will be replaced if or more likely when I replace the heater matrix with an Audi one.
Doesn't seem to affect operation in any way so kinda wonder what's the point of it!

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It controls the fans will not let them run fast until coolant is up to a certain temperature.

wammers said:

It controls the fans will not let them run fast until coolant is up to a certain temperature.

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Ahhh....that'll be why my book never appears when I have "cold" running

*looks for owners manual*

wammers said:

It controls the fans will not let them run fast until coolant is up to a certain temperature.

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I know what it's supposed to do but it doesn't seem to do it. It was minus 18 in Austria in January and the fans came on at a fairly high speed as soon as I started it. Maybe if the sensor is faulty it uses a default temp?

Wazzajnr said:

No, not Graham crook. Does he have P38 specific diagnostic? If not, he won't be much help I'm afraid.
Following Saturday I should be home but you'd have to come to mine as I'm only home for 24 hours so I'll need to spend maximum time with SWMBO

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Hi mate, sorry I didn't get back re that aircon problem. Turned out to be the receiver/dryer that had a pinprick hole in it hence no coolant. Mate of mine thought it was the pressure switch so under he went and dye all over the place. New switch/new dryer. Sorted. Happy dayz!

All sorted on the aircon front. Thought it was the pressure switch. Mate of mine took a look with the infrared light and bingo ! Dye all over the bottom of the receiver/dryer. So small the hole it took 2 months to empty the coolant. Thanx anyway peeps.