Mike951

What is different about these cars that you have to bleed the cooling system? Do you always have to worry about putting air in the system even if you're topping off the resevoir? I'm use to just a regular GM motor, pouring all the coolant i want into the bottle not having to worry about air getting in.

BartW

contraire my friend, your GM system needs to be bled as well, the only difference is that it kind of does it automatically for you when the thermostat opens and the coolant flows through, it purges itself and you only need to add coolant to the overflow bottle after a flush. The Porsche system needs to be bled in a somewhat difficult manner but I am not sure why I just know that mine had air in it before I tried some of the techniques recommended here.

Matt O.

I don't know why people say bleeding these cars is so hard. Pour coolant in (the orange stuff) and distilled H2O until you hit the mark, and either start the car or pressurize the system using a pressure tester, loosen the vent bolt at the end of the upper radiator hose, until coolant starts coming out, close it back up, . Fill the resevoir to bewteen min/max, open the vent bolt until a steady stream of coolant comes out, repeat process until your hearts content (or you no more air comes out the vent when you open).

This might not be the technical way to do it, but it worked for me, took 5 mins, and the car runs just as cool as it ever did.

-Matt

MachSchnell

What is the 'orange stuff'? I know there was a specific type of coolant we were supposed to use (because of the aluminum heads and block?) without some chemical in it, but the car came back from having the HG done with green (traditional looking) coolant in it, and I looked at my coolant bottle (prestone maybe?) and couldn't find evidence of whatever chemical that we weren't supposed to use (dang my memory sucks)

Dal Heger

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Matt Olde:
<strong>I don't know why people say bleeding these cars is so hard. Pour coolant in (the orange stuff) and distilled H2O until you hit the mark, and either start the car or pressurize the system using a pressure tester, loosen the vent bolt at the end of the upper radiator hose, until coolant starts coming out, close it back up, . Fill the resevoir to bewteen min/max, open the vent bolt until a steady stream of coolant comes out, repeat process until your hearts content (or you no more air comes out the vent when you open).

This might not be the technical way to do it, but it worked for me, took 5 mins, and the car runs just as cool as it ever did.

-Matt</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I agree, it's not that hard to do.

Dal.

Jeff928S4

Are you supposed to bleed the system when adding fluid??

I topped up my reservior last week and then just drove away. What should I expect to happen by doing this?

944S Boyeee

ahofam123

You need to use a phosphate free coolant. It comes in either green or orange but it will say safe for aluminum engine.

I also had no problem bleeding my coolant. I just get a steady stream. Considering the temp gets high and considering the ease of the bleeding, I must have done something wrong.

I think that you only have to bleed it if you let the coolant get below the hose at the bottom of the resevior.

MachSchnell

Phosphates, that was the term. Anyhow, I didn't really do a ton of research on the phosphate issue, anybody know if specific brands are good or not so good?

IceShark

If you use distilled water you can probably use any current production antifreeze without problem. The Germans have REALLY hard tap water that precipitates out so they are paranoid.

The reason our cars are so hard to bleed is that they have so many high spots above the resevior tank. So air gets trapped. Talk to engineers and they would like the tank about 10 or 20 feet above engine if they could. <img border="0" title="" alt="[Wink]" src="wink.gif" />

MachSchnell

Interesting IceShark...I was actually just sitting and pondering the fact that I used whatever coolant was on-hand for my old Nissan which, while Iron block, was, like most modern cars these days, aluminum head...it's hard to imagine that 178k trouble free miles with phosphates wouldn't have ruined the head if it was problematic (I nearly always used tap water as well) so I feel a little less stressed about the fact that I think I used the wrong stuff last time around.