[Cloud9...68]

OK, I've picked up my Prestone orange cap extended life phosphate/silicate/carb/peanut product free antifreeze, my distilled water, and I've researched prior posts on the subject of doing a coolant change on my 968, and it seems very straightforward, but I have just a few questions about how to most efficiently remove as much of the old coolant as possible:



I read in an earlier post a recommendation to jack up the car on the passenger side to impriove drainage from the radiator drain screw. But I also saw in a 944 DIY procedure that there is a drain screw on the block, and that opening this is the best way to get all the old coolant out. Does this drain screw exist on the 968 block, and is it in the same place as the 944's? Is it accessible under the gaggle of hoses?



I also read that somebody recommended removing the thermostat, which is what I've done on some other cars. Is this difficult? Does the thermostat have a gasket, or is it sealed just with sealant? Thanks.

Partial Post: Please Login or Register to read the full post.

[Darryl]

Drain plug on the 968 is the same place as the 944...bottom left hand side. Be careful during removal...these things like to break. They are basically a big plastic threaded bolt and...surprise...it gets brittle. Use a LARGE phillips head or extra wide flat blade screwdriver. The only good news is that if you do break it, it's fairly common among Mercedes, VW, BMW, etc. that all use the same style drain plug. IIRC, some may use a washer, some may not, or it's built-in. Porsche uses a washer.



As far as removing the thermostat, I didn't when I did mine, so I can't vouch for any pros or cons there.



- Darryl

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

Thanks for the tips about the drain plug. Is it fairly accessible, though? I would like to try to remove it, as I'm not comfortable just draining the old coolant through only the radiator, though I will try jacking the car up on the passenger side as well for this part of the procedure.

Partial Post: Please Login or Register to read the full post.

[Mark]

Love that Slate Gray !! Removing the thermostat is a PITA.

Partial Post: Please Login or Register to read the full post.

[bob blackwell]

The blue plastic drain plug is located on the bottem of the radiator. I have not found a drain plug for the block on the 968. Removing the thermostat from our cars is very difficult due to the location and lack of room to get to it. It requires a special tool (another one!). I have an incline in my driveway and head downhill to drain the coolant and then turn the car around and head uphill to bleed the air out of the system after refilling with new coolant. You can run the engine while draining the coolant to flush more out of the block if you really want to, but I have not found that to be necessary. Set the heater control to full hot while you are doing the flush & drain and that will get more of the old coolant out as well. Good luck, Bob Blackwell.

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

[quote name='Mark' post='36154' date='May 30 2007, 07:26 AM']Love that Slate Gray !! Removing the thermostat is a PITA.[/quote]



Thanks!



[quote name='bob blackwell' post='36156' date='May 30 2007, 08:10 AM']You can run the engine while draining the coolant to flush more out of the block if you really want to, but I have not found that to be necessary. Good luck, Bob Blackwell.[/quote]



I have always wondered about running the engine while flushing the coolant. While it shouldn't hurt anything do just do this for a short time, I've always wary of doing it. It just seems so wrong! For chickens like me, what about removing the coil wire and just cranking the engine a dozen or so times to help drive some more coolant out?

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

Well, I removed the drain plug from the radiator (very easy), let as much coolant drain out as it could on a flat surface, then jacked it up on the passenger side, and some more dribbled out. With this method, I've drained... just over 5 quarts, out of a total capacity of 8.2 qts. I then cranked the engine a few dozen times with the coil wire disconnected, and this added ... nada, not an additional drop. So much for my bright idea. I wonder why this didn't work... So, nearly half the coolant capacity is still in the block, head, and heater core. And the stuff that came out is pretty dirty looking - a very dark greenish black, so I'd like to get as much of it out as possible. I'll go hunting for the block drain plug tomorrow...

Partial Post: Please Login or Register to read the full post.

[S_Cal968]

Funny you should ask... I just recently R&R'd my heat control valve and had to drain the coolant. I pulled the blue plug and had a similar result. The reservoir was still full yet the plug was out.

I ended up slowly/carefully removing the small line that runs from the reservoir to the water pump intake - that seemed to get most of the coolant out. Unfortunately this method makes quite a mess. I suggest removing the power steering belt if you use this method.

Oddly it's recommended to change the coolant every 24 mos. yet Porsche didn't provide an easy way to do it[?!]. Even my GMC has a nice valve with a drain tube; there's no need remove any panels and there's no clean up after.

Partial Post: Please Login or Register to read the full post.

[FRporscheman]

I have the head and exhaust off of my mom's 968. I have looked very closely on the side of the engine block, where the 944 block drain is, and I haven't found anything. I looked on the whole side, then checked the other side, and I found nothing. Either it is very well hidden, or it's on the back or front...?



When you cranked, no more coolant came out because your thermostat is still closed. That's why they say to take it out momentarily. I say just warm up the car, then empty it. You can leave the engine running but it won't be necessary - just don't let it cool down too much. Wear safety stuff, as hot coolant can't be pleasant.

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

Sorry for the very late update to this post. I looked where the drain plug is supposed to be, and... nada. No trace. Even if there was a drain plug where the 944 coolant change description says it is supposed to be (bottom left hand side), with the way the the engine is tilted, I don't see how I could have gotten a screwdriver on it anyway. I had high hopes, since my car, like Darryl's (who has the elusive drain plug), is a '92. So, I ended up jacking up the car on the passenger side, then on the drivers side (to help the fluid drain from the reservoir), then from the back, and finally just left it flat overnight (which caused a susprising amount of fluid to dribble out), All told, I got maybe 3/4 of the coolant out. Pretty frustrating that Porsche couldn't have made such an important preventative task more efficient. What were they thinking...?



Anyway, since I let this go longer than I should have, I'll either (1) do this again, say, in early 2008, which will result in over 90% of the coolant being renewed, or (2) bite the bullet and replace my timing belt in the fall when it cools off (been almost 4 years, though only 23,000 miles), and take off the thermostat then to allow complete drainage.

Partial Post: Please Login or Register to read the full post.

[flash]

whenever first convenient or when you pull the thermostat, i recommend replacing the radiator hoses if they are original - they lose their elasticity over time and are known to leak and/or fail - i've seen 2 so far

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

Good suggestion, but I was very lucky to have a thorough and conscientious previous owner, and he replaced all the hoses a few years ago, so I should be OK for awhile.

Partial Post: Please Login or Register to read the full post.