996 Complete Coolant Flush DIY

[krazyk]

996 Complete Coolant Flush DIY

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I did not see a 996 coolant flush with pics so heres my contribution. My car is a 2003 C4S 6 speed and should be similar to all NA 996's as far as coolant flush is concerned (Tips have 3rd radiator). I decided to replace the coolant because I had no idea how long it had been in my nine year old car. It was the yellow color so I assume it was the correct type for the time but who knows. For refill I chose Pentosin Pentofrost even though its a little pricey at @$45 per gallon. Make sure you buy th

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• Author
  krazyk
• Category
  Carrera (996) - Maintenance
• Submitted
  01/03/2013 11:51 PM
• Updated
  01/04/2013 12:02 AM

 

[JFP in PA]

Only comment on your procedure would be to let the car sit under vacuum for at least 5 min. before commencing the system fill. Reason for waiting is that holding that car under vacuum (The vacuum level on the gauge should remain unchanged during this wait) will show if there are any leaks in the system before the often expensive coolant goes in.

[logray]

Nice write up.

You forgot one critical step which is to bleed the heater core loop while you are bleeding the entire system.

To bleed the heater core loop simply turn the ignition on and turn the heater on hi with the fans on low.

A few other tips while you are refilling:

Keep the rear end of the car jacked higher than the front, and gravity will aid the fill, although not required.

To get every last drop out of the system you can disconnect and remove the radiators and heater core and let them drain for several hours. Optionally, you can also hook up a shop vacuum attachment on "blow setting" and blow out the large coolant lines that run the length of the car to evacuate all remaining coolant from them (they have steep angles and so they can trap a lot of coolant regardless of what angle you put the car at). Coolant is caustic, so do be careful if you try this method.

It is a good idea to run the car with the bleeder valve open for a few days (with blips over 5krpm) to ensure the system is totally bled.

[Rapewta]

I had to replace the water pump last year. I didn't do this at the time. I just drained a couple gals from the drain plug. Nice DIY. Will use this tutorial next time around. Thanks.

[krazyk]

JFP, for some reason the Airlift guide said 20 or 30 seconds (not sure which). I did wait a little longer until I was sure. I can edit that part if allowed.

logray, I did mention the heater on HI and did this on mine. Maybe I need to clarify that part. I just wasnt sure if it helped or not. Your right, it is very difficult to get all the coolant out. I drained the rads from the bottom hose too but still missed @1 gallon somewhere but not sure. No indication of air in system so far.

I was curious if anyone else measured the exact amount they were able to get out without a more extensive disassemble of the system. If I change the water pump and T-stat soon, I will do it again and measure more carefully.

Edited January 14, 2013 by krazyk

[JFP in PA]

The longer dwell time under vacuum is purely a “belt and suspenders” method to test for any possible leaks; it is the perfect time to do it, especially if you had taken various parts of the cooling system apart.

It is nearly impossible to get all of the coolant out of these cars; there are just too many spots in the system where it can be trapped. On average, using the standard service procedures, you probably get 80-90% out at best. For car where we are forced to get everything out (e.g.: those that have suffered an intermix), we use an external pump system to force water or water/cleaner mixtures through the system for several cycles to push out the contaminated coolant before refilling.

[krazyk]

OK, I feel better knowing 80% to 90% is normal. I thought the same about pumping through the system but thankfully I didnt have intermix it felt it might be overkill for a regular maint. flush. Thanks for the tips. I have some others to post including a complete PS fluid flush I have never seen done before, so hopefully it will be approved. Thanks again. This forum is a gold mine for the DIY guys or those willing to learn.

Edited January 7, 2013 by krazyk

[moondoggy]

How frequently is it recommended the coolant be flushed on 996 motors. My maintenance manual from internet source and surprisingly doesn't mention coolant. Thanks.

[RFM]

According Porsche is a periodic refresh not required, only for major operations to the engine or replacing radiators and pipes = large coolant loss, it will be done. You are of course free if you wish, and maybe better, to replace the coolant after several years.

[JFP in PA]

According Porsche is a periodic refresh not required, only for major operations to the engine or replacing radiators and pipes = large coolant loss, it will be done. You are of course free if you wish, and maybe better, to replace the coolant after several years.

While Porsche does not set a time period for changing out the coolant, over the years we have observed that eventually the coolant will show signs of degradation (change in system pH, rising freeze point, development of cloudiness, etc.). This does not occur at any specific time (we have seen it in five year old cars, and had others go past 8 years with no problems). Being observant would seem more important than a calendar.

As the M96 also is also well known for its composite impeller related issues, most cars are probably going to have their system opened to replace the water pump well before the coolant begins to fade.

[moondoggy]

Thanks again for the reminder to be observant.

[JFP in PA]

Thanks again for the reminder to be observant.

Think of it this way: Quite often, the car is trying to talk to you, if you will only listen...............

[moondoggy]

2000 carrera2 w/56k miles. Is the antifreeze brand in the DIY tutorial recommended for my car? I'm a little low and need to bring level up to the MIN mark. No leaks or overheating. Is there a generic brand that can be bought at car store? Also, since I'm going to add a little bit, mix 50-50? and, use distilled water?

[1schoir]

Moondoggy:

If you are just "a little low" you can get by with just adding distilled water. A quart or so will not make an appreciable difference in the mixture.

The question of whether to use only Porsche coolant or not is a much more difficult question to answer as Porsche has gone to great lengths to protect that little profit center.

There are lots of threads discussing the type of coolant to be used and just as many opinions.

Regards, Maurice.

[JFP in PA]

2000 carrera2 w/56k miles. Is the antifreeze brand in the DIY tutorial recommended for my car? I'm a little low and need to bring level up to the MIN mark. No leaks or overheating. Is there a generic brand that can be bought at car store? Also, since I'm going to add a little bit, mix 50-50? and, use distilled water?

Here is a fairly detailed DIY from the DIY archive at the top of the page, the author chose to use an aftermarket coolant, but it would still be the same for a 50/50 OEM coolant/distilled water mix............

http://www.renntech.org/forums/tutorials/article/301-996-complete-coolant-flush-diy/

[moondoggy]

Thanks Maurice and JFP for quick replies and yes, I read the DIY. I didn't know if the pentosin pentofrost G12 was porsche or after market. And, since appears I need less than a quart, will do the distilled water. Good info again.

[JFP in PA]

Pentosin is after market, Porsche has theirs compounded to their specific OEM specs. There has been much speculation over exactly what it is, but as it is readily available, works very well, but has a reputation for not being overly compatible with some aftermarket coolants, you would need to be cautious about mixing. As a fresh batch of OEM coolant premixed with distilled water lasts for many years in a clean system, we stay with what we know works,

[moondoggy]

Thought I read somewhere to check coolant level cold and that's when I have the low reading. Checked it hot this time but found level where it's supposed to be, so no distilled needed afterall. Appears I jumped the gun. Thanks again.

[Ricardo Baptista]

On 1/6/2013 at 1:55 PM, JFP in PA said:

The longer dwell time under vacuum is purely a “belt and suspenders” method to test for any possible leaks; it is the perfect time to do it, especially if you had taken various parts of the cooling system apart.

It is nearly impossible to get all of the coolant out of these cars; there are just too many spots in the system where it can be trapped. On average, using the standard service procedures, you probably get 80-90% out at best. For car where we are forced to get everything out (e.g.: those that have suffered an intermix), we use an external pump system to force water or water/cleaner mixtures through the system for several cycles to push out the contaminated coolant before refilling.

Dear Friend

 

My car suffered from intermix and I notice that you mention that in this situation you put an external pump system to force water or water/cleaner mixtures through the system

My questions are:

1-) Where do you install this pump?

2-) May I use a bilge pump from a boat ( a rule type of pump with 1500 gph for example ) ?

3-) Is there on magic place where I install this pump and flush the whole system, or I have to go in parts? Like disconnect the hose from the thermostat nad put the pump on the hose and see the water being expelled from the metal tube OR the other way around ( pump IN on the Tube and Water OUT on the hose)

Then there is that smaller hose that goes in the pump housing ?! If I'm not mistaken?! should I flush that part of the system separated as well?

There is also the heater core on the passenger side, can I flush that part of the system with the pump?

 

Thanks 

 

Ricardo 

 

 

[JFP in PA]

We built an entire system to do this that included a hot water heater, and a catch tank, which recirculated hot water with detergent in it to clean out the system.  The pump came from a plumbing store.  We set it up with hoses that connected to the hose to the thermostat housing after removing the thermostat, and to the line coming back from the radiators.  Everything was mounted on a cart so we could role it under the car while it was up on the lift.

[Ricardo Baptista]

35 minutes ago, JFP in PA said:

We built an entire system to do this that included a hot water heater, and a catch tank, which recirculated hot water with detergent in it to clean out the system.  The pump came from a plumbing store.  We set it up with hoses that connected to the hose to the thermostat housing after removing the thermostat, and to the line coming back from the radiators.  Everything was mounted on a cart so we could role it under the car while it was up on the lift.

Dear  Friend, 

 

Thank you so much for the help and prompt answer!

Well I'll try this system as well, Will remove the thermostat from the thermostat housing, then put my pump outlet on the rubber hose that was connected to the thermostat housing and on the thermostat housing will install a hose that will drain this water in a bucket ( as a return )

Does that sound ok?! 

Sorry to be redundant, I'm not a mechanical and I want to be extra careful when doing this 

 

Thanks again and have a great week end  

[JFP in PA]

Should work fine.  The thermostat has to be remove to facilitate full flow.