Matt O.

It's been a while since I flushed a 944 coolant system, but like riding a bike, right?

So I bring up clarks garage and mainly follow that. I use the gravity method which I have had zero issues with in the past.

I am on my second distilled water only flush, each time I fill the reservoir until it is full, losen the bleed tab at the upper hose, and let a steady stream come out. Start the car and let it get to operating temp with heat/defrost full on.

Problem is: defrost is somewhat warm and heat is not warm at all.

Both flushes. System seemed to work fine before I started, as I drove the car in very cold weather and the heater worked.

Turning dial from cold to hot in the cockpit I hear the changover in the fan both in the cockpit and engine. Defrost is the same way.

The temperature gauge reads normal operating temp after 3.35 minutes of warming up. High speed fan kicks in at the normal time, then kicks off again.

I am done with the distilled water flush, and would like to put the 50/50 in there (I am using 50/50 Porsche coolant/distilled water), but I want to make sure everything is good to go.

Ideas? Am I missing something completely?

Lower, upper, and reservoir hoses are all warm to the touch as the car heats up. Water in reservoir is hot.

Thanks,
Matt

theedge

Tried revving the engine a bit? Ive always had to do that to "burp" it a bit. And holding it at higher revs.

Check the heater core valve to make sure its opening all the way?

marky522

Hey Matt, Silly question but you didnt happen to get that coolant from Leith Porsche this weekend did you?

Mark

Matt O.

Mark -- affirm -- was that you? Small world. As my wife and I left I told her, "I think there's a Rennlister who works at Leith" -- I should have asked if you were on Rennlist.

marky522

Man, if i would have know it was you i would have just lent you my vac filler.... But yes, Great meeting you by the way In te future give me a heads up, I have GALLONS of that laying around... Anytime you need anything let me know, I can get any of the special tools etc you need.

Mark

Matt O.

Mark, thanks man! Rennlist is funny that way. You get to "know" people sometimes without ever meeting them. Great to meet you as well and thanks for the info you passed on. You were very helpful.

I swapped out the old yellowed reservoir with a shiny new white one, and wanted to flush the coolant and replace with the good stuff. Previous owner used the green stuff. Got it flushed out (6 gallons of distilled later) and having the issue with the heater. I will have to try to work on it this week some but given my schedule this week I doubt that will happen. FYI I picked up the standard pressure tester from Autozone borrow-a-tool today, and will do the final fill using the pressure. I didn't care about the mess with the other flushes because they were just water (mostly). I can always find an excuse to buy a new tool (the vac filler) but I figured I'd restrain myself for now.

Which leads me to another question -- do you see a problem leaving the car without coolant/fluids for a few days? Reservoir cap off, nothing in the pipes? Or am I asking for corrosion?

Thanks,
Matt

Matt O.

Anyone have SA on if any damage can occur by leaving the cooling system open for a few days? See question in above post.

Grandpa#3

No problem leaving it for a few days, but I'd put a rag over the open tank. While the system is empty I would go ahead and change out the Heater Control Valve and clean off the grounds good with the valve out of the way.

Cheers,
Larry

marky522

Hey Matt, I have left them open for days, weeks etc with no problems. Have a good one.

Mark

951Saga

I just did mine the other weekend… what a pain! Replaced with the metal version and changed the back hose too. I should have changed it during my clutch and cam tower gasket episode.