997 Coolant capacity - I know it's in the owners manual :-)

[diceman]

So the owners manual states 32 litres for the coolant in a 997 C2S manual yet 996 is 22 litres....

Has anybody actually measured how much comes out or is replaced?

So far I have around 22 litres out and have drained from : -
1) rad lower hose at rads
2) thermostat removed
3) water pump removed
4) drain plug on engine block
5) heater feed & return at engine
6) blown through the system with low pressure from a compressor from filler cap & heater feed.
7) raised front and rear of car independently to tip out fluids



I'm buggered if I can fathom where the other 10 litres are. Are they actually there or is the manual optimistic - there appears to be a big difference between 996 and 997 in capacity.

The reason I am trying to get all coolant out is a change of coolant type, whilst it is compatible with the Porsche (pentosin G12) it's very old and I believe no longer preventing corrosion. (I know it is stated as lifetime coolant but that's a discussion for another time )

 

[jonno_]

Would it be an option to keep flushing with normal water to remove all trace of the old coolant, then drain and get new coolant up to concentration?

 

[maldren]

I had the same issue with my 996, I assumed that remaining coolant was trapped by airlocks in the rads, heater, pipes etc.

I filled the system up with clean water, ran the car and drained it again couple of times to wash out old coolant and the refilled it with the required amount of coolant and enough water to fill the system. I then 'burped' the system and all seems fine.

 

[jl-c]

The recommended way is to connect the special tool to an airline and it vacuums it all out. So much so all the rubber hoses flatten out! Then insert pipe in your new cooland reverse the tap on the tool and it all goes back in. Top up 1 liter and job done! Yes I bought the tool
https://gb-jbtools.glopalstore.com/...MIl_e-tYSq6wIVF-DtCh2A3g2lEAQYASABEgIMNfD_BwE

 

[diceman]

Thank you for the replies.

I do have one of the vacuum filler devices (not the one above but same design). The instructions indicate that they are not to remove coolant and you should remove the coolant before use; apparently they spray the coolant everywhere from the air-out port) I'm hoping adding an extra hose on the air-out port to a second bucket will prevent this but we'll see!

As I'm changing coolant type (reported to be compatible with OEM but hopefully better corrosion resistance) I'm keen to get as much out as possible first go. I may end up filling with distilled water a couple of times to flush the system depending on what comes out during the vacuum procedure! As I'm potentially missing 10 litres of coolant (left in system) I've purchased a load of distilled water as a back up plan.

 

[jl-c]

Interesting, never had that issue and according to the instructions ( yes, I am 'the one ' who reads them ) it is the job it is designed for :dont know: :dont know:

 

[diceman]

Interesting.

It's either that I bought a cheaper e-bay variant (error 1 )
or that I just need to crack on and try it as I've never used one before.

 

[diceman]

To update: -

I vacuum excavated the cooling system to the suggested level of vacuum (25 in HG) . No coolant was removed during this process - absolutely none came out the vacuum tool hose.

All soft hoses were pulled flat (I have much of the car apart so can see them). It held pressure fine whilst left so hopefully no leaks.

First fill from the vacuum method took 17 litres, added 1 litre to the header tank to bring up to max mark so 18 litres in total so far.

I need to put the car back together before first fire up and burping the system. Maybe a little more to add I suspect but I can't see it being 14 litres to make 32! I have an issue if there's 14 litres of air in the system!

 

[jonno_]

Can you raise the rear of the car once its back together?
Sure its been posted on here, but IIRC its a matter of heater to max, start it, hold 2.5k revs (only for a few mins) whilst someone fills the header tank.

Then keep a litre or two to hand in the car, a couple of spirited drives (up to temp) with the bleed loop "up", keep an close eye on oil and water temps.

Top off, lower bleed loop. Job done.

(the above is from memory)

 

[deMort]

I've had engines out , replaced the over engine coolant pipes and i get in the region of 20 ltrs back into the system .. 25 ltr drum so i know the amount .

I can see a bit more being left in the system but not an extra 10 litres so im dubious of this amount being correct .. it might be but im struggling probably like you to know where that large amount sits as its not in the rads or coolant pipes .

 

[diceman]

Thank you Demort (again!). It's very reassuring to know I'm not way off on quantities.

It does mean I've over ordered the qty of coolant!