Poor Heater.

[DaveEFI]

The heater on my 987.2 takes ages to get hot. Basic unit - not climate control. Even when the coolant temp gauge shows normal, still no real heat until some time later. It's a PDK, so spends all its time around town at low revs. Lock it in a low gear and rev it, and the heater kicks in. So wondered if if it could be an airlock of some sort? Is there a procedure for bleeding any air out? Other than the heater, the cooling system seems normal - no leaks or whatever. Car mileage is about 33,000.

[Liberty]

Take this with a pinch of salt but you could leave the bleed valve open for a couple of days?

[Mattman42]

i have a 987.2 PDK as well - the windscreen demist can take up to 10mins if its really cold as mine takes a while to warm up to, although once the temp guage gets close to 60 i do get heat coming out.

Have you tried it with the A/C on as well - that seems to accelerate the demist for me

[sa utah]

I’d say air in the system.   Or water pump.   
 

if you’ve not changed the coolant in the last few years I’d use it as a good excuse to have it drained and refilled at an Indy.   
 

 

[DaveEFI]

I've looked up the refill procedure, which involves a special tool. But nothing about bleeding the system. It seems obvious to me that coolant is circulating OK to the rads - so why so slow to get to the heater matrix?

 

[The Caped Crusader]

Special tool? I'm not aware of this. 

I would bleed the system to start with. On the 3.4, the bleed valve is under the engine cover adjacent to the filler caps in the boot.  On the 3.2, the bleed valve is under a cover below the two fill caps in the boot. 

[DaveEFI]

Thanks. It's a 987.2 3.4S. Couldn't find any mention of a bleed valve by Googling.

[Paul P]

I think the bleed valve moved in gen 2 to on top of the engine accessed via this top cover. 
 

traditionally engine warming up but cabin staying cold was thermostat.  Much more technical these days of course it but my 987.2 starts to warm quickly. (3 mins and dash air is above ambient ) but it really only gets  hot at 10 to 15 mins running and more than 2k revs.  I figure it’s more about thermostat fully opening for fuel/ economy reasons rather then “The driver is cold” 

My London traffic runs are end of the day so the car isnt stone cold 10mins in traffic normally sees it starting to be warm enough. 

[sa utah]

The “special tool “ refers to a vaccum tool which is used to create a vacuum in the cooling system and then allows coolant to flow into said vacuum, this prevents any air locks.  The tool is about 60 quid and you need a compressor.  So much easier to take it to an Indy or an OPC as you’ll not use those items again for a while I’d guess  

Or you can muddle on and hope you’ve got it right   

 

[DaveEFI]

Seems the special tool was mentioned on 2005 instructions. But no mention of a bleed valve anywhere. Which is surprising if it has one.

[Liberty]

On 11/8/2019 at 10:36 AM, DaveEFI said:

I've looked up the refill procedure, which involves a special tool. But nothing about bleeding the system. It seems obvious to me that coolant is circulating OK to the rads - so why so slow to get to the heater matrix?

 

From the little I’ve picked up the heater matrix is the high point in the system so it’s where the air ends up.As others have said your bleed valve is in the engine bay rather than the usual place.As for the special tools I’d say Porsche put in a bleed valve for a reason but someone else may be able to blow my reasoning out of the water and educate me too ..