Please Help - 2002 Spyder - Heater not working...no hot air from vents

[giantoak]

All the HVAC controls appear to be working...all temperature changes show on the centre screen, the vent/demist all switch and work OK, but only cold air ever comes out of the vents.

Car has only been used during summer months for several years now so I can't say how long the ventilation system has been permanently set to 'OFF' - perhaps 5 years?

It could be a blocked heater matrix, but I'm thinking more likely to be a valve seized shut...or maybe suffering a bad connection or fuse.

I've looked at countless diagrams but not been able to find out how the flow of hot water to the heather matrix is controlled, where the valve is located and which fuse it is connected to. Would be much appreciated if someone put me out of my misery and tell where to look?

Thanks in anticipation...

 

[2b1ask1]

Possibly the obvious question but are you sure the matrix has not been bypassed because of a leak?

 

[Zep]

Possibly the obvious question but are you sure the matrix has not been bypassed because of a leak?

This!

 

[giantoak]

Thanks...a good point for others who might read this post in the future....but definitely not bypassed, I've owned this car 13 years and there was a time when it did work...

 

[Zep]

Ah. In that case, I’d bet on the valve or the valve actuator.

 

[giantoak]

Yes, that's what I'm thinking...but do you know where it is?

 

[Zep]

It is going to be inside the bulkhead. This may help / scare the bjesus out of you:

https://www.sportsmaserati.co.uk/index.php?threads/how-to-heater-matrix-repair.23166/

 

[conaero]

Have you changed the coolant recently?

It could simply be an airlock.

 

[giantoak]

No coolant hasn't been changed for quite some time...that could be the reason for the fault...

 

[giantoak]

It is going to be inside the bulkhead. This may help / scare the bjesus out of you:

https://www.sportsmaserati.co.uk/index.php?threads/how-to-heater-matrix-repair.23166/

I did look at this excellent post and studied photos, but couldn't see anything that looked like a control valve

 

[Oneball]

Looking at the parts diagrams I don’t think there’s a control valve that cuts off coolant to the heater matrix. I think the air temp is controlled by flaps within the heater box that change air flow.

Two options for me either the flap is stuck or the heater air temp sensor is broken.

 

[lovellracing]

If its the same as a 3200 the whole of the dash has to come out to get to a couple of control valves that stick. From memory one of them is the same as an Alfa Romeo not sure which model now as it was around 5 years ago I remember doing a small mod to one of them so it doesn't happen again!

 

[giantoak]

If its the same as a 3200 the whole of the dash has to come out to get to a couple of control valves that stick. From memory one of them is the same as an Alfa Romeo not sure which model now as it was around 5 years ago I remember doing a small mod to one of them so it doesn't happen again!

Oh I do so hope this is not the case...and lovellracing is right and that one way or another I can get to the flaps/sensor without taking half the car apart!

 

[giantoak]

Looking at the parts diagrams I don’t think there’s a control valve that cuts off coolant to the heater matrix. I think the air temp is controlled by flaps within the heater box that change air flow.

Two options for me either the flap is stuck or the heater air temp sensor is broken.

Thanks for the helpful steer - I was puzzled by not being able to find a control valve in the diagrams.

 

[conaero]

No coolant hasn't been changed for quite some time...that could be the reason for the fault...

I would drop it and flush it several times as it may have turned to jelly.

It should be red coolant in your car btw.

 

[giantoak]

I would drop it and flush it several times as it may have turned to jelly.

It should be red coolant in your car btw.

Thanks...that's a must do even if it doesn't fix anything. Other than being red, what coolant would you recommend ?

 

[conaero]

Buy the best you can afford and just make sure it’s red.

GranTurismo is blue btw

 

[jasst]

Buy the best you can afford and just make sure it’s red.

This is very interesting, I always thought the 4200 used blue, but i have filled mine with G13 red as it lasts for 5 years, but a chap on one of the fb groups said not to use red as it is acidic and eats away at seals, and he claimed to have seen lots of problems caused by red.

 

[conaero]

Well we just use factory spec but I agree this is odd. The GranTurismo and 4200 engine is basically the same but use different colours so go figure?

 

[Zep]

I think it is just products.

4200 is Agip Antifreeze Plus Ecopermanent - turquoise

GT is Glycoshell or Glycoshell Long Life - Blue

Both meet CUNA 956-16 and it seems that the only difference is that the Glycoshell long life has OATs.