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Changing the coolant in your 997.2. Please note I only got a bit more than 6 gallons in/out of the system so please post your technique if you can get more out. My procedure here is not complete, although it is pretty easy.
Why?
1 - Voice number 37 in my head won the argument
2 - I don't "believe" in life time fluids... just don't.
3 - My history with cars going way back... my family and I always had cooling system problems as our cars aged. I know modern fluids are better, but I am taking no chances.
Objective:
Change out as much fluid as I could without climbing under the car. See, I don't like laying on my back and sliding under a car.... I just don't like it... won't do it.... ain't gonna happen. My service manual and all on-line tutorials I read denote removing the under-pan, and disconnecting the supply and return lines. This will get the fluid out from the radiators and any sitting in the pipes. I did not do this and will not. Others have posted that you can drain the radiators and pipes by removing the front bumper, and then disconnecting there. Too big of a job for me, didn't do it.
My procedure - Not the best
Wha? First, I got just over 6 gallons out and in. Per my manual, the system capacity is 7.63 - 8.32 U.S. gallons so I fell a bit short. Where was the remaining fluid? I am not 100% sure, but probably in the heater core (I forgot to run the fan and HOT while draining) and some left in the big pipes from/to the radiators. Do I care? Sure, but I accomplished my goal of putting good fluid into the system... I am happy with my results.
Approach Summary:
1 - Pump/suck out the fluid from the reservoir (I didn't think of it, but it may have drained down through the draincocks)
2 - Remove the two draincocks under the engine in the rear to drain the engine (return and supply side)
3 - Remove the airbox to access the supply and return lines to the engine, disconnect them, attache a fat hose (from an old shop vac) to the left return line, and then use air pressure into the supply line (right side) to blow them clean, this will push the fluid and air forward through the radiators and out the return line
4 - Suck out the remaining fluid from the top of the thermostat housing (where the return line connected)
5 - Button it all up and use an UView Airlift to draw the new fluid in
6 - Drive to full heat in oil, then get revs up to 6K a few times to blow through any trapped air... the next morning, I had to add maybe two pints at most.. not much at all... the airlift did its job well.
Difficulty:
Fairly easy with the correct tools, buckets, etc. It took me hours and hours as I was trying to figure out a better way to do all of this and running experiments by blowing and sucking anything I could get my tool into. I learned these piping tricks from an old girlfriend in Cleveland.
General Comments:
The fluid I removed was pretty cherry red. Not real dark but not light. I never changed this fluid in my ownership and I purchased the car with 26K miles on it... so I suspect it is original. My friend at Ford said when coolant gets old, it gets darker. If the original stuff was pink, then something definitely changed and this supports my suspicion that this fluid is not a life time fluid. Something is getting deposited or maybe the chemistry for corrosion and other protectants are getting used up and reacted with.
I used Zerex G40 instead of the Porsche-labeled stuff. From my research, I believe it is the same mystical fluid. It comes in either a 50/50 mix ready to use, or as a concentrate you mix with distilled water. It is way cheaper to buy the concentrate. I recommend buying it from you local Napa store. Call the store (not the on-line store) and they will have it delivered over-night. You pick it up the next day with NO SHIPPING fee. Pelican. ECS, and the other on-line sources charge about $23 for shipping four gallons of this stuff bringing their price to about $34 per gallon. At Napa, the price was $25 per gallon after calling ahead.
Best to get your distilled water at a drug store. Crazy as it may sound, if you buy it at a super market, you have to be careful because it will say "Distilled Water" and then say "minerals added for flavor" in super tiny print. WTF? Seriously, watch out for this.
I purchased two new draincocks and washers from my local Porsche dealer.... call first, one dealer did not keep stock, the other did. You can probably re-use the old ones, but they were in there pretty firmly and one was tough to remove... my allen bit got pretty stuck in one which tells me they may round off. Best to get new ones.
I purchased the more expensive airlift... I saw a video where the cheaper on uses just a plug and had trouble holding a vacuum when the vacuum got low... the more expensive unit has a locking ring (I used one of their adapters) that expands the plug to lock into place. Needed? I dunno.
I used my Porter Cable 6 Gallon compressor and it works fine. When I drew suction, it needed to refill a few times. I shut off the airlift valve, let it refill, and away I went. It produced more vacuum than needed.
First remove the airbox to get access to the supply and return hoses.
To remove the large supply line, right side, you pull off a clip, then grab the hose and start to wiggle... it will pull straight out. To remove the large return line on the left, use the hose clamp pliers and slide the clamp up the hose. Then use the curved pick to loosen the hose seal and pull straight out. When you remove these hoses, there will be spillage so place a tone of towels around them... I made a mess. I attached a short length of shop vac hose to the left coolant return hose and jammed it down through the pulleys down to the catch pan. The fluid from the radiators will exit here and if you don't route it down past your engine bay, you will have a royal mess.
To blow out the line, I used the big triangular plug from the airlift kit and pressed it into the supply hose on the right side and then pressed in my air hose squirter and let fly. Beware, the fluid will come shooting out so watch so the catch pan does not overflow. I then jacked up the front end of my car way high using two jacks and got a bit more fluid out. Lower the car, re-attache the hoses, install the new draincocks.
I am not sure how to get the fluid out of the heater core. Some have said to run the fan and set temp to HI (hot) and that will open the heater core valve. I knew this but just forgot to do it. As I think about it, I wonder if it would have created a "loop" that would have interfered with blowing out the radiators. I dunno, but if it did, the issue can be remedied but shutting down the fan, move to low, and pull out the key. I think... post here if you know the answer to this.
Attache the airlift to the coolant reservoir. Do not use the big conical plug. I needed to add an adapter ring supplied in the kit, then screw down the locking ring until snug. Nice system.
To prime the fluid supply line (so you don't suck in air when filling, start to draw vaccum, and let it build a small amount, then shut off the valve and remove the air hose line. Then attach the fluid supply hose, open both valves and let the fuid draw up until it hits the valve... then shut both off. Now reattach the air hose and bring the vacuum into the green.. I got it to about "27" were it slowed to a stop. Shut off the valve, detach the air hose, and attach the fluid supply line. Wait for a few minutes to ensure the vacuum is held else you have a leak somewhere. I read that I was supposed to turn on the fan and temp to HI but I forgot this, this may open the heater core but I am not sure. Then open the valve, watch the fluid flow, the vaccum drop and and marvel at your genius. When it stops filling, shut off the valve, and remove the airlift valve. It was hard to know when the fluid stopped drawing, but then I saw a little bubble appear at the valve. This air came from the reservoir. There was still some vacuum pressure. I did not need to top off the reservoir as it was filled perfectly.
Reinstall the airbox and ensure your car is back to normal. Start the car and let it warm up. If you are sure you got a good fill, then take the car for a drive. Stop the car and check the reservoir. If still filled ... my level never moved... then go out on the highway and get those revs up over 6K. Next morning, top off if needed... I needed to add less than two pints if that.
Since this procedure, I took my car on two, two hour trips at crazy speeds and the level never moved. I guess the airlift did its job well.
Oh, cleanup.. you can see in the photos I got coolant all over my engine bay. I sprayed Simple Green (4 to 1 water to cleaner) all around in there, then used my garden hose on sprinkle and hosed the whole thing down. Don't worry, you won't hurt your engine. Actually I went ahead and cleaned my whole engine bay... just spray that solution in there... liberally. Then I used some car cleaner pokey thingys and rammed them all around to clean the top of the engine, between things.. all over. I used the garden hose on sprinkle and hosed the entire engine and bay. I did cover the throttle body by stretching a rubber glove over the opening. When you start your engine, the water just burns off as the engine heats up. You do get some steaming and a clean engine. Thanx to Rob, RTL for that engine cleaning approach. It works!!!!
$112.49
(2) 999 063 038 01 Sealing plug M14 X 1.5 (few bucks) Tighten to 19 ft lbs
(2) 900 123 104 30 Seal Ring 14 X 18 (few bucks)
Air compressor with an air squirter attachment to blow out fluid (6 gallon pancake works fine)
$10 from Amazon Hooked pick to remove left, return hose from Harbor Freight $1.99
A large clean bucket to hold 8 gallons of fluid
Small flat buckets to catch fluid (I used Her clothing storage boxes)
Allen bit (6mm) to remove the draincocks
A short length of hose from an old shop vac to route the draining fluid from the return line down to the flat catch pan
A clamp to hold the fluid supply line in the bucket (you do not want the end to lift and enter air into the system)
Peace
Bruce in Philly
That is an old shop vac hose I cut short, and rammed down to the catch pan.
That is the big conical rubber cork from the airlift kit I rammed into the hose.
Last edited by Bruce In Philly; 08-22-2020 at 07:16 PM.
Thanks Bruce. I plan on doing this and my water pump in a little while. I think I read you are still on your original water pump. I have 105k on the clock. No issues, but no fluid lives forever.
For a guy that claims he started wrenching late, your work is very professional and you have caught up the the best of them. excellent write up and pics also.
Remember boys and girls, as stated in the title, this is for the 997.2 car. the 997.1 will be somewhat similar, but still different.
As to "lifetime", this is a marketing term, not from the engineering department.
As you stated, the coolant can not last forever. Coolant ,oil, brake fluid, hydraulic fluid, paint, leather, people, etc are all organic materials and will oxidize over time and temperature.
I think this lifetime thing started back in the eighties with lots of people in the U S bought lots fancy European cars. Although they did not break like the American iron, the maintenance cost (dealer) was sky high over what they were used to. To combat the cost issue Maintenance intervals was extended on some items. The first one I remember was diff and gearbox oil on BMW (manual trans, we are a 3 pedal family) as being noted in the owners book as "lifetime". At the same time the manufacturers decided that the commercial life of vehicles was about 100,000 miles ( not to be confused with mechanical life) So, since the "life" was now about 100,000 miles, the statement about "lifetime fluids was not incorrect in the scheme and therefore made in past engineering signoff. The sales guys all ran out and shouted "lifetime".
Anyone knows you change gearbox & diff oil at 60,000 miles and sooner with the older non synthetic oils. I was very surprised when I found out that Porsche called the coolant lifetime, as I do not think other manufacturer's do this . However I have not checked this in a number of years. BMW called out coolant flush and brake flush every two years and this is correct in my book. However for BMW with a normal cooling system of "in", "out" and two heater hoses, you can do this standing up in about 10 minutes and refill with one jug of coolant and one of distilled water. $25.00 and finished! If Porsche on the other hand wanted to call out an interval, the cost would be some giant number due to the complexity of the system and the 8 (!) gallons of material. So the decision was made I guess to just call it lifetime. Then it does not show up in the penciled out cost of ownership for these fancy cars. One technical point that I do not know is the actual coolant operating temperature in the 997.2 . The gauge calls out 175 but the gauge only knows what the computer tells it as it is not in anyway connected to the cooling system. BMW has a 220 degree F thermostat and the whole system fails every 60,000 to 80,000 miles.
Long winded, but Bruce is exactly right, Change the coolant and I would say do it at approx 80,000 to 100,000 miles or so. No need to do it every two years or less that 80,000 miles as the chemistry is so stable in the corrosion inhibitors now . The old coolant even at 100,000 miles will be surprisingly fresh looking , still pink, /red. However it will have a brownish cast when compared to the new material. Then there is the life of the coolant tank........
Nice write up as always Bruce.
I'll be doing the coolant flush on mine soon, but at the same time will be installing a new thermostat, water pump and 3rd radiator in addition to a whole bunch of other preventative and fun stuff
So in my case I will be interested to see how much more I can drain by having access to the front hoses. Will let you know.
For a guy that claims he started wrenching late, your work is very professional and you have caught up the the best of them. excellent write up and pics also.
Remember boys and girls, as stated in the title, this is for the 997.2 car. the 997.1 will be somewhat similar, but still different.
As to "lifetime", this is a marketing term, not from the engineering department.
As you stated, the coolant can not last forever. Coolant ,oil, brake fluid, hydraulic fluid, paint, leather, people, etc are all organic materials and will oxidize over time and temperature.
I think this lifetime thing started back in the eighties with lots of people in the U S bought lots fancy European cars. Although they did not break like the American iron, the maintenance cost (dealer) was sky high over what they were used to. To combat the cost issue Maintenance intervals was extended on some items. The first one I remember was diff and gearbox oil on BMW (manual trans, we are a 3 pedal family) as being noted in the owners book as "lifetime". At the same time the manufacturers decided that the commercial life of vehicles was about 100,000 miles ( not to be confused with mechanical life) So, since the "life" was now about 100,000 miles, the statement about "lifetime fluids was not incorrect in the scheme and therefore made in past engineering signoff. The sales guys all ran out and shouted "lifetime".
Anyone knows you change gearbox & diff oil at 60,000 miles and sooner with the older non synthetic oils. I was very surprised when I found out that Porsche called the coolant lifetime, as I do not think other manufacturer's do this . However I have not checked this in a number of years. BMW called out coolant flush and brake flush every two years and this is correct in my book. However for BMW with a normal cooling system of "in", "out" and two heater hoses, you can do this standing up in about 10 minutes and refill with one jug of coolant and one of distilled water. $25.00 and finished! If Porsche on the other hand wanted to call out an interval, the cost would be some giant number due to the complexity of the system and the 8 (!) gallons of material. So the decision was made I guess to just call it lifetime. Then it does not show up in the penciled out cost of ownership for these fancy cars. One technical point that I do not know is the actual coolant operating temperature in the 997.2 . The gauge calls out 175 but the gauge only knows what the computer tells it as it is not in anyway connected to the cooling system. BMW has a 220 degree F thermostat and the whole system fails every 60,000 to 80,000 miles.
Long winded, but Bruce is exactly right, Change the coolant and I would say do it at approx 80,000 to 100,000 miles or so. No need to do it every two years or less that 80,000 miles as the chemistry is so stable in the corrosion inhibitors now . The old coolant even at 100,000 miles will be surprisingly fresh looking , still pink, /red. However it will have a brownish cast when compared to the new material. Then there is the life of the coolant tank........
FWIW, my 2005 Tacoma and Toyota's in general label their coolant Long Life and Supra Long Life. My Tacoma has 279K miles and I'm the original owner. I just flushed it out at 275K miles and it was still pink no corrosion and still on the original water pump. The same thing with my transmission fluid since Toyota stated that the AT transmission were no serviceable. The rear and front diff, were easily over a 100K miles. The truck has been used to tow my moto trailer to and from the race track, been off roading many times, and been solid since taking delivery.
I'm not trying to start a debate, I'm just sharing my experience.
OK, we see all the pictures of your cruddy, filthy, disgustingly dirty engine compartment caused by all the off-roading for your photo shoots by the bay. (As a side note to all you readers, I was present when an independent mechanic removed Bruce's under car shields, and we were all stunned by the pounds of debris, dirt, sand and general detritus which was trapped in the void between the shields and the mechanical components and which fell onto the garage floor. He had to sweep up before he could work on the car.)
Let's see the cleaned up version! I would especially like to see it after you complete your Ceramic Coating.
@Bruce In Philly I can confirm you did well with the amount of coolant drain you got with your process.
Even with access to the front rad hoses and running the heater resulted in less drain than you got (even with lifting/tilting the car alternately from all 4 corners )
4.75 gall is all that would self drain from front and back without additional pressure or vacuum through some of the hoses as you did.
I actually have the first one on your list although I got mine on Amazon as I needed it right away. I have used it on probably 6 different cars and it works great. The green valve handles are a bit delicate, but are okay. Besides that it is a good kit that can be used on lots of different vehicles.
Bruce, the reservoir has a minimum level and a maximum level. When you topped off the system how full did you make it re the max and min marks? Some years ago, One of the Lord of the Manor’s friends was over and wanted to see the engine in the 911. The car had been sitting overnight so the engine was cold. The coolant was near the minimum mark and the friend suggested it should be halfway between upper and lower marks. He commandeered my jug of distilled water, which I use for almost legal purposes, and added it to the reservoir.
Later that year we were on a driving holiday and stopped for a while at Lake Tahoe, it had been extra hot all through the mountains, but the car was perfect. We planed to head to the coast to meet friends at Monterey and wanted to cross over the Sierra Nevada mountains via the super steep, narrow, and extra twisty Sonora Pass.
At the base of the pass, it was hot, (nearly 100 degrees) but the water and oil temps were in a pretty normal range all the way to the 9,600 ft summit. We stopped at the top and instead of letting the engine run for a minute or so to keep the coolant circulating we stupidly just stitched the engine off. As we got out, we heard a gushing sound as a cup or two of coolant exited the pressure valve in the reservoir cap and made its way down to the red-hot left muffler stinking up the whole mountain.
We decided that the high barometric pressure and lower temperatures at sea level, where we live in Canada kept the extra coolant in the tank. The thorough heat soaking expanding the coolant as we raced up to 10,000 ft where the low air pressure could not help the cap keep the tempest in. What do you think Yes/No?
After adding coolant each morning for a few days on the way home, it stopped needing top-ups and has been stable ever since.
Bruce, the reservoir has a minimum level and a maximum level. When you topped off the system how full did you make it re the max and min marks? Some years ago, One of the Lord of the Manor’s friends was over and wanted to see the engine in the 911. The car had been sitting overnight so the engine was cold. The coolant was near the minimum mark and the friend suggested it should be halfway between upper and lower marks. He commandeered my jug of distilled water, which I use for almost legal purposes, and added it to the reservoir.
Later that year we were on a driving holiday and stopped for a while at Lake Tahoe, it had been extra hot all through the mountains, but the car was perfect. We planed to head to the coast to meet friends at Monterey and wanted to cross over the Sierra Nevada mountains via the super steep, narrow, and extra twisty Sonora Pass.
At the base of the pass, it was hot, (nearly 100 degrees) but the water and oil temps were in a pretty normal range all the way to the 9,600 ft summit. We stopped at the top and instead of letting the engine run for a minute or so to keep the coolant circulating we stupidly just stitched the engine off. As we got out, we heard a gushing sound as a cup or two of coolant exited the pressure valve in the reservoir cap and made its way down to the red-hot left muffler stinking up the whole mountain.
We decided that the high barometric pressure and lower temperatures at sea level, where we live in Canada kept the extra coolant in the tank. The thorough heat soaking expanding the coolant as we raced up to 10,000 ft where the low air pressure could not help the cap keep the tempest in. What do you think Yes/No?
After adding coolant each morning for a few days on the way home, it stopped needing top-ups and has been stable ever since.
I just checked my coolant level... cold car... just a hair above MIN. When I topped off after running the car hot and over 6K RPMs, I only added less than two pints if that to bring it to MAX. I spot checked it and when I am in there for whatever reason such as oil changes..... Always at MIN or near MAX.
I have no comment on the affects of altitude. Sounds like there was some air in the system and it blew out coolant... thus requiring you to add more when it cooled down. Given Germany and their markets around the world have big mountains... I kinda doubt that was a normal occurrence. But I am no expert on cooling systems... better get advice from someone who really knows something.
Just something to think about... just because it is stable does not mean there is not still some air in the system. Take the car out, put the heater up to HI.... get it hot, and get the revs up to 6K and old it there for a a bit and cycle this a few times. I kinda bet you will have to add some fluid.
Peace
Bruce in Philly
Last edited by Bruce In Philly; 01-09-2021 at 12:09 PM.
Sonora Pass is beautiful but in the midst of spirited driving on those warm summer days in the thin mountain air that you describe I've seen my oil temps hit 275F and the water temps exceed the dummy value of 175F. In other words, you may have experienced boil over.
The loads on the car are greater going east but this is the morning outbound direction for me when the outside temp is cooler. The ambient temps are higher on the return and this is where I see the higher operating temps.
I actually have the first one on your list although I got mine on Amazon as I needed it right away. I have used it on probably 6 different cars and it works great. The green valve handles are a bit delicate, but are okay. Besides that it is a good kit that can be used on lots of different vehicles.
08-22-2020 | 05:40 PM
Coolant Flush/Change 997.2 9A1 DIY
