new to me - 99 SV - HVAC hot issue

Hi, I've been a watcher on here for many years, but finally got my Lamborghini at long last (having sat in my first one and visited the factory in 1985)

 

Its a 99 SV Coupe, and as can be expected it has a few niggles that I'd like to try and sort out myself...

I've done some searches in the forum already, but couldn't find these covered.

 

1. HVAC seems to only get hotter and hotter - no cooling whatsoever, and turning the climate control down doesn't seem to do anything.

suspect the R134 is low.

Engine temperature sat at 80deg C (170 deg F) on a long run for 2+ hours on the motorway/freeway.

I'm thinking thermostat or blend valve is stuck ?

How could I diagnose further ? who an ODBII scanner reveal anything ?

I haven't checked the coolant level - will check that out tomorrow, as its a little warm at the moment

 

2. Windows are very slow and sometimes stop - suspect earthing issues with cabling ? or just poor connections on the switches ?

I've got some Stabilant 22 that I'll start to use on the connectors from now on - starting with the window switches

 

I guess I'm bound to find a few more issues, and will keep you posted.

 

Congrats Davo! - Sorry I can't help with the technical stuff but what you say makes sense to try and resolve.

 

Let's see some pictures of the beast!

 

OBDII won't tell you anything about the AC. It could be freon, but you need to see if the compressor is turning on at all, could be a relay, fuse, and yes it can be the climate control module itself. Mine failed very early on. Just take it one at a time. You need to access the relay fuse compartment in the engine bay behind the carbon fiber panel drivers side.

Engine temperature sat at 80deg C (170 deg F) on a long run for 2+ hours on the motorway/freeway.

I'm thinking thermostat or blend valve is stuck ?

 

80C is the expected temperature on the freeway. When you slow down or stop the temperature will creep up to 85-90 at which point the fans will turn on to bring the temperature back down.

 

Windows are always slow, but they shouldnt stop

Slow windows is the motors I thought.

OBDII won't tell you anything about the AC. It could be freon, but you need to see if the compressor is turning on at all, could be a relay, fuse, and yes it can be the climate control module itself. Mine failed very early on. Just take it one at a time. You need to access the relay fuse compartment in the engine bay behind the carbon fiber panel drivers side.

 

ok, thanks for the heads up about the OBDII,

I don't think its the compressor - I think I have low R134 - buts that's another issue.

It runs hot, and won't get cooler when I adjust the controls - even though the outside temperature and incoming air is 9 deg C.

I suspect I need to find the air inlet, and make sure that's not blocked.

 

How did you Climate Control unit fail ? what's the symptoms ?

 

I'll check out the fuses too.

 

Many Thanks

Now that I think about it, my failed climate control would not adjust up or down. Pretty clear it was bad, so dismiss that.

Slow up and down windows are most commonly NOT bad wire or bad motors...MOST common issue is the felt lining in the window track had become worn and shinny smooth...they will slow the windw done. If real bad, they have to be replaced..but most of the time can just clean them real good with mild soap and warm water, as well as wet sand them with a fine grit sand paper, then they should work a lot better.

Roy is dead on about the slow windows. Normal is the seals that the window rides in should be replaced. To test this add a bit of lube in both channels the window should work better.

 

If A/C is blowing hot air will not be R 134 charge level as it would blow about what the outside temp is. If the air is heated then the heater control valve is not working or the rubber seal on the insert inside of it is torn and leaking hot coolant into heater core. Or there is a bad temp sensor which will make the system default into a heat mode.

 

The heater control valve is in the right side rocker there is a small access panel in bottom just in front of right rear wheel. there is a plug going to the valve it needs 12 volts to that plug to close valve. If it has 12 volts and you are getting hot air then the insert is most likely bad. If it dose not have 12 volts then most likely there is a bad temp sensor and the system is in default heat mode. You can also put a hose clamp on the hose going to or from the heater control valve if it starts to blow cold air or the same as out side temp then you will know this is the issue. It will take a few for the temp to drop after you clamp off the hose as it will still have hot coolant in heater core.

Slow up and down windows are most commonly NOT bad wire or bad motors...MOST common issue is the felt lining in the window track had become worn and shinny smooth...they will slow the windw done. If real bad, they have to be replaced..but most of the time can just clean them real good with mild soap and warm water, as well as wet sand them with a fine grit sand paper, then they should work a lot better.

 

so you mean the vertical channels inside the doors ? rather than the felt at the top of the door that is horizontal ?

 

Roy is dead on about the slow windows. Normal is the seals that the window rides in should be replaced. To test this add a bit of lube in both channels the window should work better.

 

If A/C is blowing hot air will not be R 134 charge level as it would blow about what the outside temp is. If the air is heated then the heater control valve is not working or the rubber seal on the insert inside of it is torn and leaking hot coolant into heater core. Or there is a bad temp sensor which will make the system default into a heat mode.

 

The heater control valve is in the right side rocker there is a small access panel in bottom just in front of right rear wheel. there is a plug going to the valve it needs 12 volts to that plug to close valve. If it has 12 volts and you are getting hot air then the insert is most likely bad. If it dose not have 12 volts then most likely there is a bad temp sensor and the system is in default heat mode. You can also put a hose clamp on the hose going to or from the heater control valve if it starts to blow cold air or the same as out side temp then you will know this is the issue. It will take a few for the temp to drop after you clamp off the hose as it will still have hot coolant in heater core.

 

I checked fuse A5 today, which is the fuse to the H2O valve, and that was fine - as you say it seems the sensor failsafe mode is to fail open without power, putting maximum heat into the cabin!

I'll check the valve out next. Many Thanks

Slow up and down windows are most commonly NOT bad wire or bad motors...MOST common issue is the felt lining in the window track had become worn and shinny smooth...they will slow the windw done. If real bad, they have to be replaced..but most of the time can just clean them real good with mild soap and warm water, as well as wet sand them with a fine grit sand paper, then they should work a lot better.

 

Thanks Roy - cleaned, sanded and go all the way up now - Many Thanks!

 

[quote name='jefflambo' date='Nov 29 2013, 02:46 PM' post='1081392'

 

If A/C is blowing hot air will not be R 134 charge level as it would blow about what the outside temp is. If the air is heated then the heater control valve is not working or the rubber seal on the insert inside of it is torn and leaking hot coolant into heater core. Or there is a bad temp sensor which will make the system default into a heat mode.

 

The heater control valve is in the right side rocker there is a small access panel in bottom just in front of right rear wheel. there is a plug going to the valve it needs 12 volts to that plug to close valve. If it has 12 volts and you are getting hot air then the insert is most likely bad. If it dose not have 12 volts then most likely there is a bad temp sensor and the system is in default heat mode. You can also put a hose clamp on the hose going to or from the heater control valve if it starts to blow cold air or the same as out side temp then you will know this is the issue. It will take a few for the temp to drop after you clamp off the hose as it will still have hot coolant in heater core.

 

Hi Jeff,

 

I took the cover off the panel in front of the right rear wheel, and found the fuel tank and 2 sets of hoses with 4 inline fuel filters.

My car is RHD, so I'm wondering if its different ?

 

The parts shots and 94VT workshop manual show the electrovalve underneath the passenger side (I think that means RHS) dashboard, but I've took a look under both sides of the dash and can't make it out. (see part 7 on pic)

Is this a dash out job ?

 

 

unplugged the Control panel on the dash looking to check out the 4 temperature sensors - cabling is not on the back of the control unit.

cabling for 4 temperature sensors is next to the solenoid valves under the dash on the right hand side (passenger on a LHD car).

Unplugged them and checked resistance as per workshop manual - all within 2 deg C of what they should be.

Plugged everything back in.

 

Went for a long drive today, and didn't bake in the car !

So starting to think a bad connection, that I've resolved by moving things.

Typical Alfa Romeo type problem!

 

Need to top up AC next, and see if problem really goes away.

Starting to think this car needs more use, but its not the weather in the UK for this for another 2-3 months yet!

ok, been a while since I updated this thread...

 

basically heater issue seemed to fix itself after I had the AC fan replaced.

But then came back later on a long run after 1 hour of driving.

AC working fine, then after 1 hour, cabin starts to get hot even though control set on 18 deg C - like hot water is flowing to the heater, even though it should NOT be.

 

Seems valve (part 7 of the parts picture) that looks the likely culprit.

 

I finally found the location of the part in a RHD car - its under a small inspection panel in the driver's side door sill - removal of the complete sill is required to fit it I believe.

 

I ordered part 006031658 from Lamborghini, and it arrived today - see pic.

 

Its a bosch part 1147412208, but as I can't see any pictures of that alone on the web, so I'm not sure whether it includes the piping or not.

 

I will try and fit at the weekend, and see how things go after that.