Bruce In Philly

2009 C2S 96K miles

I am hearing voices in my head.... the coolant in my car is talking evil to me.

So:

1) Cooling capacity aside, doesn't coolant deteriorate over time and use? I hear the corrosion resistance properties deteriorate.

2) Replacement procedure.... Can't I just drain it and fill it? I did some research and some have some pretty complex procedures. Will simple drain and fill leave bubbles in the engine that won't flush out? I don't really care to remove 100%, but a good 95% replacement would be fine no?

There is some real history here for me..... In almost all the cars I or my parents have owned, at some point around 100K miles, developed radiator leaks. The shops would tell me I should have changed the coolant... something about corrosion from the inside.

Another point is I normally I follow the manual... but my recent experience with changing MT oil well before the 120K stated interval was dramatic. So, I am not against, let's say, doing a bit more and a bit early. And lastly, 100K miles is something of a milestone with cars... maybe I am programmed with the old 70's Detroit stuff that literally ejected parts at 100K miles.... but... when a car of mine nears this mark, I start looking at things very closely. I figure at 100K, if I swap something out, I will get another 100K..... emotions? maybe... but its those darn voices....

I am expecting a long tome from Macster...... (a compliment!)

Peace
Bruce in Philly

BIG smoke

My coolant generally gets changed along with the water pump. Its very difficult to gather all that coolant off the garage floor when the pump pops. So I just use new.
On my other cars, I do it every five years. Like my chevy. Dealer does it, a fair charge. I have someone to yell at, if things go wrong. Solves the "voices in my head" issue you are having.

Carmichael

"Lifetime coolant"

I would test the coolant in your reservoir once, maybe twice a year with coolant test strips. It is literally a litmus test for the coolant. If it checks out, great. Drive on.

I've seen the damage not changing your coolant out will do. My '86 325es had been sitting since 1996, and the corrosion on the aluminum parts, like the water neck and thermostat housing was pretty bad.

Newer cars are better with that, but then you have to worry about plastic parts getting brittle.

DB's997

Had this conversation with my service manager at Porsche dealership.
Said with aluminum engine it does last 10 years. but water pump failed. Got new serpentine belt and new coolant with water pump on my old 996

Rikky001

Lifetime - 10 years can be OK.
Test pH once a year and look for signs of cracks/ leaks on your expansion tank.
Nothing wrong to change the coolant if done properly. I see people changing their coolant out with the expensive Porsche coolant and tap water, don't do this, use distilled water instead.


It is a good idea to exchange your thermostat to the type that opens at a lower temperature, other than that I keep the coolant system un- touched. It is a closed circuit which makes it is not exposed to air which deteriorate the coolant inhibitors over time.

user 72902

Change your coolant but you'll still be hearing voices.

I change my water pump every 4 years and the coolant as well. The coolant will always have the ability to transfer heat but it does loose its ability to prevent corrosion.

I've done this procedure many times and I can only get about 6.5 gallons out of the system. I have a third radiator so I figured I had 8+ gallons. But when trying Evan's Waterless I sent a sample to verify that I was under 3% water (I had 2%). Based on that I was pretty convinced I had the system empty.

I have an Airlift and some say you can empty it with that but I have had no such luck. Pulling the drain plug and venting the coolant reservoir will net about 2 gallons. Repeated pulls with the Airlift gets more out but what did the trick was to take a leaf blower to the supply for the radiators and the heater core and catch it on the other side with a bucket. I can go into details if you want me to.

Good luck buddy

140.6er

I'm subscribed

jhbrennan

Owner's manual says capacity is approximately 8.45 gallons - wonder where the other 2 gallons are...and how you get it out?

ADias

Nothing is lifetime. I changed coolant at 5 years - I had it done at the dealer I trust (Fletcher Jones Porsche) and supplied 4/5 gallons of distilled water to mix with dealer supplied Porsche coolant.

Rikky001

Have to disagree with your statement, no offense.
Coolant which is not exposed to air as in our cooling systems will not loose its corrosion inhibitors and the heat transfer is not related with aging coolant. Different story on an open system where the exposure to air will deteriorate the coolant properties and require dosing or exchange.

dgjks6

Not a 911, but our 08 Audi q7 is well past 150K miles. Original coolant. Had a long talk with the service dept about just changing it and they said no. They have not seen problems from old coolant. And I figure I got to trust them. I was offering to pay for a service and they turned me down.

Macster

I've always changed the coolant periodically in all my cars/vehicles (I owned a pick up truck once) and have only had to replace one, no, two water pumps. The 1st was in the Boxster at 172K miles. The other was the Turbo water pump at around 120K miles. (Other vehicles covered anywhere from 28K miles (Camarao Z28 I owned for just 4 months before buying the Boxster) to 50K miles up to over 140K miles with no water pump issues.)

The Boxster pump got noisy. I believe it wore out. The Turbo pump developed a leak. I believe the ~6 years the coolant was in the engine contributed to seal degradation and even though the coolant was replaced shortly after I bought the car the water pump seal "damage" was already done.

Cooling is not affected by coolant age. Anti-corrosion additives and I understand there is something in the Porsche anti-freeze to help the water pump seal and bearing survive detoriorates over time.

Might mention too there are a number of very expensive and very critical heat exchangers -- radiators and heater core and oil/water heater exchanger -- that have relatively thin walls I prefer to replace the coolant every 4 to 5 years vs. facing the real possibility of having to replace these. The radiators in the Boxster are original. The Turbo radiators - all 3 -- developed leaks at 130K miles and were replaced, at a cost of over $4000.

In the older models, the 986/996, there is an engine block drain one can use to remove the coolant from the engine. Before opening the drain one should pinch off the hoses to keep the coolant in the hoses from the engine to the radiators and in the radiators from draining.

Then one can top up the engine cooling system with a fresh mix of Porsche anti-freeze and distilled water then remove the clamps that pinch off the hoses. While this doesn't replace the entire load of coolant it replaces around half of it and improves its additive state. This is better than not replacing any coolant but not as good as replacing all of it.

However, I do not know if the newer models have this engine coolant drain.

Frankly that is too much work. My preference would be to just drain the entire system and refill with fresh coolant. If I did this at home I'd get a vacuum lift system to ensure properly filing with no air pockets. That technique of running the engine and getting it hot then adding coolant and repeating ad nauseum is just too shade tree-ish for me.

When due I just have the coolant replaced at the dealer as part of the car's other servicing. Takes nearly no time as this can be done concurrently with other servicing so I save some money.