Hi,

Having just replaced head gasket and got all back together working, i was feeling very impressed with myself, well until the wife got in and put the air con on........ warm air coming out no matter what i did.

The air con was fully functional before i did the head gasket and it was re gassed approx 2 mths prior. When i did the head gasket i did not remove any hoses only removed compressor from the housing and put it out of the way but still connected.(not electrically - only by the refrigerant hoses).

There is no signs of any leaks of refrigerant.

The clutch engages when the switch on the HEVAC is pressed and disengages when it is pressed again.The small hose from the compressor get very hot shortly after the engine is started, the outlet hose from the condenser is ok to touch and is very much lower temperature than the inlet pipe. the condenser fans do not run but i don't think that there is a need for them to run.Checked all fuses - all ok. Relays look ok but i dont suspect a problem with them.

Do have the cheque book light come up on the HEVAC after approx 10 minutes that can be reset by switch engine off then on but this was the case before i did the head gasket so dont think this is to do with the current fault although its another job on the list)

Any one got any ideas or suggestion of some checks/tests that i can perform ?

In moving the compressor out of the way could i and introduced a fault ?

It is a P38 - YR 2000 with a petrol 4.0L Thor engine.

Hi, you should find your answer here under Common Symptoms & Causes and Repair Operations.
If you need more help I'II be back in town later in the week.

Could be a stalled Temperature blender motor...

Does the temp get warmer if you increase the temp controls?

I know you have recently had the system regassed - but are you sure no gas could have escaped? The only reason I ask is your symptoms are EXACTLY the same as mine before I had the system regassed, has worked perfectly since it was regassed.

Cheers

Jerry

The flexible hoses may have become porous and when you disturbed them it caused a slow seepage of gas. However as you get one hot pipe and one cold my guess would be blend motor, especially as you have the book symbol.

Hi all,

Thanks for your responses - apologoes for the delayed response my router decided to break down in sympathy for the RR.

ZZR1200 - thanks for the link - took a look bit could not find anything.

Datatek - you could be right the blend or one of them may befaulty - as i said i have the book light up before i worked on it.

Saint V8 - thanks for the suggestion - the temperature changes from luke warm to hot

Jerryltr - you were the closest.

I took the car to a RR garage in Progress Rd ( ZZR1200 - you prob know where this is as your a local) and they got out their diagnostic thingy and plugged it in and found lots of faults with the HEVAC but could not be sure if any one of them was the problem so suggested reset all codes, which they did and to book it in for a full diagnostics starting with a re-gas, i didn't book it in but took it to another place (Bonair on Mano Trading)that specialised in auto air con.Spoke to a bloke there who knew he stuff,salt of the earth and bloody helpful to boot.

He checked the system out with a UV light and sunglasses and found that there was a leak/hole half way down on the from left of the condensor - he summised that i have lost a lot of gas but not enough for the low pressure switch to engage and disengage the clutch.

He sucked out the remaining stuff and calculated that of approx 1300g i should of had - i had just 180g.

Long and short of it is i have new condensor and receiver on its way to me to be fitted then a trip down to the air con man for a re-gas.He even FOC sucked the remaining gas and put a vaauum in the system so that oi could work on it

RAVE says to lube the o rings in compresor oil - is there an alternative as seems a waste to buy 1ltr for thimble full ?

Also - anyone know the part no of the 2 foam blocks either end of the condensor that are fixed to the cross member ( where the paint code is) as mine are solid and rock hard ?

n18rks said:

Hi all,

Thanks for your responses - apologoes for the delayed response my router decided to break down in sympathy for the RR.

ZZR1200 - thanks for the link - took a look bit could not find anything.

Datatek - you could be right the blend or one of them may befaulty - as i said i have the book light up before i worked on it.

Saint V8 - thanks for the suggestion - the temperature changes from luke warm to hot

Jerryltr - you were the closest.

I took the car to a RR garage in Progress Rd ( ZZR1200 - you prob know where this is as your a local) and they got out their diagnostic thingy and plugged it in and found lots of faults with the HEVAC but could not be sure if any one of them was the problem so suggested reset all codes, which they did and to book it in for a full diagnostics starting with a re-gas, i didn't book it in but took it to another place (Bonair on Mano Trading)that specialised in auto air con.Spoke to a bloke there who knew he stuff,salt of the earth and bloody helpful to boot.

He checked the system out with a UV light and sunglasses and found that there was a leak/hole half way down on the from left of the condensor - he summised that i have lost a lot of gas but not enough for the low pressure switch to engage and disengage the clutch.

He sucked out the remaining stuff and calculated that of approx 1300g i should of had - i had just 180g.

Long and short of it is i have new condensor and receiver on its way to me to be fitted then a trip down to the air con man for a re-gas.He even FOC sucked the remaining gas and put a vaauum in the system so that oi could work on it

RAVE says to lube the o rings in compresor oil - is there an alternative as seems a waste to buy 1ltr for thimble full ?

Also - anyone know the part no of the 2 foam blocks either end of the condensor that are fixed to the cross member ( where the paint code is) as mine are solid and rock hard ?

Click to expand...

I said Blend motor first....(throws toys out of pram..!!)

n18rks said:

I took the car to a RR garage in Progress Rd ( ZZR1200 - you prob know where this is as your a local) and they got out their diagnostic thingy and plugged it in and found lots of faults with the HEVAC but could not be sure if any one of them was the problem so suggested reset all codes, which they did and to book it in for a full diagnostics starting with a re-gas,

Click to expand...

Never been there, l always do my own repairs (including reading the fault codes), I've only ever paid for re-gassing and mot's.

n18rks said:

i didn't book it in but took it to another place (Bonair on Mano Trading)that specialised in auto air con.Spoke to a bloke there who knew he stuff,salt of the earth and bloody helpful to boot.

He checked the system out with a UV light and sunglasses and found that there was a leak/hole half way down on the from left of the condensor - he summised that i have lost a lot of gas but not enough for the low pressure switch to engage and disengage the clutch.

He sucked out the remaining stuff and calculated that of approx 1300g i should of had - i had just 180g.

Click to expand...

I"II remember them could be useful for A/C bits.

Any idea how much do they charge for re-gassing?

quoted me £49.99 for a regas but because it took them longer than normal because their machine ran out of gas and they had to change the bottle so they only charged me £42.

Anyway - all air con working fab - have been away for a week and everything running sweet - 265 fault free miles down the back lanes of Kent and East Sussex.Until..............................................it overheated, spat coolant out of expansion tank - ?????? for absolutely no reason at all (i think that viscous fan clutch is faulty as it was when engine was under heavy acceleration going up hill from standing start) - no split pipes - water pump & thermostat replaced when i did the h-gaskett. Flushed engine and rad to ensure no blockages as well.

Filled up with water and managed to get 6 miler before she overheated again.No ryhme or reason ??

In the end could take the chance anymore or risk a damaged engine and back to square 1 so joined the AA and got recovered back to Rayleigh on a low loader- i am looking at the fans this weekend:

The fan behind the radiator turns but i found that if i take the cover off i can stop it by putting a gloved hand on the fan - i can even spin it a few turns the opposite way before the engine turns it direction and spins it the other way - this surely cant be right

The condenser fans - have tested the resistance of the fan coils and i get a dead short - when i wired up them direct to the battery neither turned - find it hard to believe that both have shorted out out - am going to try to short the pressure switch this weekend as i final test to see if they work.

In summary - having done all the head gaskett work it drove fault free for 265 miles - i think that a new viscous clutch is req as well as new condenser fans (dependent on test from shorting across pressure switch)

oh the joys of being a P38 owner, i mean sponser !!!

Viscous fan is shot.
It would help if you told us if it's petrol or diesel.
How did you connect the condensor fans to the battery? Unless you completely disconnected them before you did it you could damage things.
On a meter the fans will read an almost dead short unless you can measure on a low ohms range. I can give you a simple mod to use the condensor fans for cooling.

Hi Datatek,

I agree, the viscous clutch is shot and i will replace it.

The vehicle is It is a P38 - YR 2000 with a petrol 4.0L Thor engine, this has not changed since my first post.

Ref the condenser fans - when i removed them to fit the new condenser i wired them directly to the battery ( out of circuit - direct from connector to battery)

I am interested in see what you have for using the condenser fans as cooling however (except for this week) the UK weather may not need additional cooling.

Thanks

n18rks said:

Hi Datatek,

I agree, the viscous clutch is shot and i will replace it.

The vehicle is It is a P38 - YR 2000 with a petrol 4.0L Thor engine, this has not changed since my first post.

Ref the condenser fans - when i removed them to fit the new condenser i wired them directly to the battery ( out of circuit - direct from connector to battery)

I am interested in see what you have for using the condenser fans as cooling however (except for this week) the UK weather may not need additional cooling.

Thanks

Click to expand...

PM me with an email address and I will send you my mod to use the aircon fans for supplementry cooling

Ref testing condenser fans:

previously removed both condenser fans and measured resistance - got dead short, tried to connect them individually to the battery and neither turned.

Did some digging and found a thread that suggested grounding pin 3 of the connector on dual pressure switch.Does this test need to be down with the connector connected ? i am guessing that it would ? any advice

n18rks said:

Ref testing condenser fans:

previously removed both condenser fans and measured resistance - got dead short, tried to connect them individually to the battery and neither turned.

Did some digging and found a thread that suggested grounding pin 3 of the connector on dual pressure switch.Does this test need to be down with the connector connected ? i am guessing that it would ? any advice

Click to expand...

See the mod I sent you