Coolant system upgrading
 

Its appears that the 944 coolant system is basically flawed due to the difficutly in bleeding the system and that Linsdey Racing install a line from the rear of the head to the header tank to eliminate a potential air pocket in that location. Now I do not want to go the Lindsey route at the moment so I am looking at either a swirl pot install on the top hose or feeding in another line perhaps by using the thermo valve socket, I am guessing that the bleed valve is in too high a position for a permanent line to the header....Any thoughts?

It's really not THAT difficult to bleed. I park mine as nose-high as I can, turn on the heat full blast, fire it up, loosen the bleeder screw and wait till coolant starts to trickle out. I'll do this a couple of times. However, I'm going to get me a vacuum bleeder kit since I now have 2 944's and the Audi A8 we have is a "bleeder" too.

Super easy to pressure bleed it, easy enough to bleed as per the manual as well. No need to buy anything, you can pressure bleed by blowing into the overflow tube with your palm over the coolant tank neck. With a wrench on the bleed screw it's bled in 2 minutes.

The D2 A8/S8 is trivial to bleed as well unless the bleeder valves break apart.

Since when is a 944 hard to bleed?

Park nose high, open the heater fully, fill tank with water, let engine warm up, crack the bleed screw and keep adding water until steady water comes out the screw.

10 minutes?

TO be blunt you're looking to spend money to come up with a solution to a problem that doesn't exist.
The Lindsey kit is for something else.

Pulling a vacuum on the system, now that's a cool idea.
Where do you hook up the vac source?

I find that filling the expansion tank almost to the top helps as you then have a fluid level above the bleed valve. When done remove a little to get down to the max fill line and you're good to go.
Never been a problem.

Jon

i've had a couple of them argue with me, and require a second burping after a short drive, but really it was only because it was hard to get the engine hot enough to open the thermostat.

that's one of the reasons i drill every thermostat

944 can be bled in minutes... just open the heater, and put the front in the air, biased on the side of the expansion tank (making it the high point). Open the bleeder and pour coolant into the tank until it dribbles out. Close bleeder and drive. Repeat after car has been brought up to temp and cooled back down enough to safely open system. I don't get why people have so many problems bleeding

Spend $100.00 and buy a Stant coolant system pressure tester ... the adaptor fits right on
the expansion tank , just pressurize to 15psi and open the bleeder screw and you're done !

It will also work with many other vehicles.

When bleeding, I find it speeds things to place a clean towel over the reservoir fill and blow into it. A little mouth-to-mouth resuscitation, if you will. Doing so pushes air out of the head quickly. You can use a dedicated pressurization tool too, but it's not necessary.

I've done that before. Leave the bleeder open, pinch off the overflow tube with one hand, give that reservoir some mouth to mouth resuscitation, and with the other hand on the bleeder screw, tighten it up when I feel coolant coming out with my finger. Then give it a final tightening with the 12mm wrench.

It's easier to put your palm over the water neck and blow into the overflow tube. You can even open-close the bleeder with a wrench in your left hand. Blow-open-close-breathe-blow...
Rinse off the end of the overflow tube first. easier than it sounds.

That'll work too. I think I'll do that next time. I just did it (mouth to mouth) that way one day many moons ago out of frustration and it worked. You're right, it makes it easier to close and open the bleeder. Plus you can WATCH it too... Kind of hard to see it when your face is planted down onto the overflow reservoir.. LOL

Refilled my coolant last night (using gravity, as per my other post) and noticed that after the bleed screw is shut, you can sometimes get air out (bubbling through tank) by just squeezing the hoses. Did that and re-opened the bleeder, started the motor, and closed it when coolant came out. Runs on the first hash mark.

Bleeding is PRS (pure rocket science)

I use the tall funnel approach: Funnel stuck in piece of heater hose and crammed in filler neck. Open bleeder and pour in coolant until air is out. However it tends to overfill the coolant tank.

I like these other methods more.

Really the best method is to jack up the left front of the car, so the chassis is at a 17 degree angle longitudinally, and a 27 degree angle laterally. I then stand on my left foot and pressurize the expansion tank with a nitrogen filled polyprene bladder clenched under my right armpit. While I open the Lindsey Racing Hyper Titanium Gaseous Release Modulator with my free hand and gently kick the bumper with my right foot, an assistant plays an original pressing of die Valkyrie on a 78RPM German phonograph.

roflmao - thanks - ready for that drink now

I ditched the radiator altogether. Too much of a pita to bleed. I tied in another a/c line after the drier, got a 4 ton expansion valve, put in a commercial evaporator and two fans where the radiator was.

Air cooled, man.

Well once its bleed and I am happy that the coolant system is bullet proof then in goes the Waterless coolant but at a £120 dont want to get it wrong. I am going to slightly modify the system buy joining into the the 10mm hose at the coolant bottle and running this through a barbtail connector in place of the thermo valve. The way I see it is when the thermostat opens and the water rushes through the bottom hose the pump and circuit can not deliver enough water through the block hence the rear air pocket forming, now with my simple mod it may just nullify this and then no more jacking car in the air..

Because of the error in my ways my engine needs HGH - Head gasket help...