Coolant question

[metropolis986]

This is my first post (had my Boxster S for a month and a half now, 2002 reg), I have noticed the last week or so that the coolant level is a bit low, just slightly off the Min mark (this is on a cold engine on level ground). It hasn't changed over this week at all nor has a warning light ever come on. The coolant temp gauge reads in the normal position when the engine warms up (i.e. halfway through). Also when the engine is warmed up the coolant level is in normal levels (almost halfway between the Min and Max mark).

I do have a bottle of the right Porsche coolant from the dealership but am hesitating to use it for a couple of reasons; a) I don't know what coolant the previous owner has in the tank and have heard that mixing them could lead to gelling issues b) the manual also states that equal measures of distilled water and coolant should be added, not just coolant on its own... Does b) mean that I need to find distilled water too (and where from?)? I thought most coolants were pre-mixed with water these days (this was the case for the OAT brand I used for my previous car anyway).

Any advice on the above? Would really appreciate it as I am new to Porsches and the Boxster! The car is due for a service in a few weeks time anyway btw but I really don't want to risk anything!

 

[GOOFY]

Personaly of its more than 3 years old I would have the coolant system flushed and refilled !

 

[metropolis986]

The car has regular service history so I imagine the bleeding/refilling bit has already happened several times?

 

[Buddy]

All sounds fine to me, engine temp is steady, not losing coolant and no warnings.

The original anti freeze should be ok for years and if there is any doubt have the SG checked.

Porsche do not recommend regular coolant change.

 

[metropolis986]

Buddy thanks, like I said in my first post the only worry I have is the manual clearly states that the coolant (when engine is cold) should be between the Min and Max mark and mine is (slightly) below Min.

 

[Buddy]

Mine has been pretty well the same on each Porsche I've had and I found a long time ago that if it was in the band between min & max when cold then it would overflow a bit when hot.

On the day I collected my Boxster I drove about 50 miles on the M1 and then drove through the car park near home to do some shopping, It blew a load of coolant out so I let it cool then checked and it was above min so just kept an eye on it over the next few days and it didn't change.

 

[CLIFFWILKINS]

Try changing the coolant cap only about £12.00
one of ours used to get a little low before advice to change the cap
all good after the change

 

[metropolis986]

Thanks, sounds like I shouldn't worry about it too much. Like I mentioned it will be serviced at the dealership in a few weeks time so I'll just wait and see what they say too.

 

[Buddy]

Just keep an eye on it and you'll soon know if it is a real problem but it's most likely not.

 

[metropolis986]

I am checking it every day for the last 10 days now and there's been no change whatsoever.

I will make sure the dealership tops it up properly in a few weeks. I am hesitating doing it myself despite having a bottle of Porsche coolant as I have heard some gelling horror stories when mixing occurs and since I've only had the cars for a couple of months I have no idea what coolant is in there now.

 

[AlphaWhisky]

I've just had to have the water pump replaced on my Boxster. I initially though the rattling was the heat shield - the fixings on these are prone to corrosion - but two days later the water pump fell apart. Still, it had done well, having seen the car through more than 111,000 miles.

In my 25 years of driving and owning cars, never before have I experienced rattling as a precursor to a failed water pump. Usually they just start to sound noisy with more of a whooshing sound.

Anyway, with respect to coolant, I've honestly not heard of gelling issues. Most coolants are a pretty standard mix these days and I do wonder if some of the manufacturers claims are to make the customer feel obliged to buy their product over and above a generic brand. Similarly with engine oil, obviously one should never mix grades, but mixing brands should not produce problems, or at least, this is what I have learned from a friend who works for a well known oil company.

 

[metropolis986]

You're probably right, it's just that I'd rather not risk it (with gelling).

I did buy a bottle of coolant from the Porsche dealership recently (just as a backup) and to be fair to them I didn't think it was that expensive anyway (or at least not as expensive as I thought Porsche antifreeze would be ).

 

[Buddy]

Not too badly priced if buying just one bottle for topping up but to refill if you drain it then it gets expensive as the cooling system has a very large capacity.

 

[AlphaWhisky]

ORIGINAL: Buddy

Not too badly priced if buying just one bottle for topping up but to refill if you drain it then it gets expensive as the cooling system has a very large capacity.

Yes, an awfully large capacity of 10 litres!!!

£40 for the coolant alone and that was with an independent Porsche specialist who let me pay cash for the work and didn't charge me the VAT on top!

 

[BartyB]

If you suspect a coolant leak but there are no signs of coolant leaking out under the car, the coolant reservoir cap is OK and the pressure relief valve housing seal is OK , it could be worth checking to see whether the coolant reservoir has split. A symptom of this is condensation on the trunk lid above the coolant reservoir. More information about this here.

 

[metropolis986]

No sign of condensation. No sign of the coolant loss either, it has remained at exactly the same level since I first observed it weeks ago. I think I will leave it to the dealership to top up/drain when it goes in for a service in a few weeks.

 

[boxter s]

Some really useful info here. Does anyone know where I can buy distilled water from to re-fill my coolant system? Also do others always use Porsche coolant or is there an equally good alternative? Also I've read when flushing the coolant and re-filling it is possible to get an air lock, how would I know if I've got an air lock in the system?

 

[Buddy]

Generally speaking in most engines people use tap water but either demin or deionised would be more pure, my local shop doesn't sell distilled so I'm not sure if this is a common thing, purer water is usually only used for lead acid batteries.

The Porsche antifreeze is what most use although others will be suitable provided they are intended for use in all Aluminium engines but personally I'd stay with the Porsche stuff. Porsche recommend a high concentration of 50% antifreeze which if I remember correctly give protection down to -35C.

First indication that you have an airlock is usually that you can't get the full required amount of antifreeze and water in although this can mean that you still have some coolant or flushing water left in the system, basically you must do all possible to bleed air off from the highest point both cold and then hot if air remains within the circuit it will cause overheating. So make sure you know where all bleed points for the system are.

This is just general and applicable to any water cooled engine.