Clint's 944

In reference the following thread I had earlier...

https://rennlist.com/forums/924-931-944-951-968-forum/244265-ok-gurus-what-is-going-on-with-my-car-update.html

OK, so I replaced the bad rad. cap and the radiator. I filled up the coolant and bled the system as per Clark's Garage. (I've done this before so I am pretty confident I did it right...or perhaps not)

I dug through the archives but I all I found was...bleed, bleed and more bleed. Well, been there.... done that!

Problem #1
The fans are not working properly. They worked the first couple times I had the car back together. Then they wouldn't work and as soon as I was about to throw something..they worked again? Narrowed it down to the fan switch. Funny thing is that the fan switch was fine in the other radiator before I moved it onto the new one. Is it that fragile?

Problem #2
I keep beeding the system and as soon as I think it's done....more air. I mean ALOT of air every time.
To bleed it, I jacked the car up in the air as high as I could. Turned the heat full on. Bled it while it was cold then I warmed up the car and bled it again. I still didn't have any heat so I knew there was more air.
So I pressurized the system and bled it that way...NO heat and more air!
So I took a quick drive and bled the system again..more air. Tried the heat and it was still cold. So another drive..another bleed...more air. I did this over and over while adding coolant whenever it dipped low. Each time, a massive amount of air came out and stil no heat at idle. How can I get the air out heater valve for good?

Thanks for any help!!
~Clint

nine-44

I turn the temp to full hot but the fan on low, this will allow it to heat up with the heater valve open. Rocks car was bled out pretty good but when I moved the car I heard it bubble and the coolant dropped. I put the driver's front corner the highest I can and let it idle with the system sealed up and the temp on high(low fan tho), when the hoses start to stiffen(pressure) I start to bleed the system. Good luck

RedlineMan

Hey;

Your fans are working screwy because of air pockets. You messed the switch by disturbing it. Sometimes that all it takes.

You do 90% of the work before you even start the car. Fill the rad/tank. Open the scew and listen to it wheeze as the level drops like a stone. Refill and go do something else. Come back & refill. Go do something else. Close the screw, squeeze the lower hose a few times, watch the bubbles rise in the tank. Open the screw, wheeze. Fill again. Go do something else. When you can open the screw, squeeze the hose, and get a squirt from the screw, you are ready to bleed. When fluid dribbles out the srew on its own, you are REALLY ready to bleed.

Start the car, crank the heat, open the screw, pin the revs at 2500 and let it go. It won't do anything for a while, then it will start to sputter, then blurp, then ****. ONLY when you get a solid steady strong jet of coolant coming out are you done. It will take longer than you think, but you will know when the jet phase arrives. Rinse everything externally with clean water when you are done. Takes me a total of 10-15 minutes. Works every time.

Oh... and open the screw away from the belts and distributor cap, eh?

Clint's 944

Hmmm...2500 rpm? That makes sense, I'll try that tomorrow morning!

You gotta love Rennlist!

Thanks!
~Clint

nine-44

oops, sorry, I fill the system with the bleeder open also, just somehow didn't post it. Sorry

Clint's 944

You know, it was never this difficult on my old n/a to bleed the air out?
On the other hand, it sure was sweet to drive the car today...it's been almost 3 weeks!!!

Clint's 944

OK,
1. I jacked up the car on the drivers front.
2. I opened the rad cap and pressurized the system with 5# of pressure until the coolant came out the bleeder screw in a nice steady stream.
3. I then started the car and let it idle until it warmed up.
4. Then I reved the motor to 2500 rpm and opened the bleeder screw.
5. Steam steam and more steam...that's all!
6. I noticed the coolant went down pretty low and pretty much stayed there.

I let it sit there for 30 minutes with nothing but steam coming out of the bleeder screw. However, the fans were working. It seems that it would maintain the temp at just below the red as long as the bleeder screw was open and the defrost was on.

How long does it take to bleed out the air?

Could the system be drawing air into the cooling system somehow?

Thanks,
~Clint

Clint's 944

I tried it again, nothing but alot more steam but I now have heat at idle!

The temp still stays at just below red, the red light is on but the needle is not in the red.

When I tuned the car off, I can hear the radiator gurgling and the is some gurgling at the back of the motor near the heater valve.

Should i keep trying?

RedlineMan

You got something wierd going on;

If you do it like I said, it should not take too long to get fluid out the screw when it is running. But again, most of your work should be done by that point. You don't need to jack it up or pressurize the system or any of that. You were pushing that fluid out with a big airbubble behind it! It's a lot EASIER than this... really.

Open the screw and fill. Close the screw and "milk" the hose A LOT. Open the screw, listen to the wheeze, and watch the tank drop. By squeezing the lower hose, you are pumping air out of the engine, and fluid runs in to replace it. Engine run bleeding shouldn't take more than 5 minutes or so.

Your high temp reading is because the sending unit is surrounded by steam, i.e. boiling water, i.e. 212 degress or higher? Get it? Start out and do it just like I said, then start the engine. If it takes me 15 minutes, I spend 10 filling and milking, and only 5 bleeding.

Do like I said. You'll get it!

nickg

i am having this exact issue with my s2...the deal is that you cannot just pout it in the bleed hole, it is on the side of the top neck, 90 degrees from vertical. I will do what you guys say here...it's killing me on my 91...I am just about to sell the car

User 41221

Something weird is going on, Clint. If you have a coolant system pressure tester, follow these steps:

Do this with a cold engine.

1) Open the bleeder screw.
2) Fill the system with coolant.
3) Close the bleeder screw.
4) Attach the pressure tester, and pump it up between 11-15psi.
5) Crack open the bleeder valve, it should take less than 15 seconds for it to bleed all the air out. Keep an eye on the level of coolant in the expansion tank, stop and fill it up during this process if it drops to the bottom (it shouldn't if you already have a partially filled system to begin with). Cose the bleeder valve.
6) Start the car up, run it for about 5 minutes with the heater on full blast, watch your temp gauge and coolant tank level.

It should be fine at this point, and not require further bleeding. Check to make sure the system is holding pressure by squeezing the top radiator hose, it should be hard. If its not, you have a leak in the system.

Regards,

GlenL

Not happy to add this, but have you considered a head gasket failure?

triscadek

I had a head gasket failure on an Accord and it pumped comression or exhaust, not sure which, into the cooling system.

It finally built enough pressure that the plastic tank on the radiator blew wide open.

nickg

the problem with this is that an s2 has the upper hose directly attached to the bottle with a branch hose, the only thing toing you pressueize is the fluid between the tank and the screw, it takes the path of least resistance...while doing nothing for the heater core.. I have been struggling wioth this very problem for 3 months

Clint's 944

Well, I think I finally got it!!!

I removed the rear coolant hose off the throttle body and fished it backwards so I could hold it straight up. I filled it up with coolant and jumped on the car to get it moving. Alot of bubbles came up so I thought it was working. I then clamped the other hose coming off the thyrottle body and pressurized the system a little bit. More air and gurgling noises came out of the heater core. I did this over and over while hopping on the car then I would jack up the up and down and little by little more air came out.
After no more air came out and I wasted a gallon of coolant, I put the throttle body coolant hoses back on and ran the engine for a little while at 4K rpm. Then I opened the bleeder screw and some more air came out. Then I shut the car off and hooked up my motive power bleeder filled with coolant to the expansion tank. I milked the ALL the coolant hoses when it was slightly pressurized and the I would release the pressure and milk them again. I did this for about an hour and little by little more air came bubbling up.
Now came the fun part.....
I took the car lfor a little flogging! There is a new neighborhood going up and there are no houses, just open road. So, I started nailing the throttle in 2nd gear up to redline, then slam on the brakes while yanking the wheel back and forth. It was kinda fun! I did that for about 10-15 minutes and then checked the coolant level. Sure 'nough, it was low! Woo Hoo!
So, I added more coolant and then took another "spirited" drive! I checked it again and the level had not dropped. Now were getting somewhere!

After I got back to the house, I let it sit in the driveway until it cooled off. I then bled it EXACTLY the way Redlineman said except at 3500 RPM. This time it was spitting air and coolant all over the place until finally a nice steady stream came out! Yep, it shot coolant out 4 feet in like 4 different directions at once! I was a tad soaked trying to tighten the bleeder screw! LOL After that I let the car idle and it is holding the proper temperature and the heat works!

I think the heater core was the root of the problem, maybe it was just too much air in the system for it to bleed properly, who knows....it took a long time and multiple ways to SLOWLY get the air out. I'm going to let cool completely and then I will take a drive around town tonight and see how it goes.

Nick- You may want to try it my way. It takes a long time (5+ hours) and hell of alot of "milking" but it eventually worked. Let me know how it goes!

Thanks again everyone!
~Clint