Tommygunn944

I brought my 944 out of winterization yesterday afternoon, a little early but I couldn't wait! At the end of Fall I noticed a few drops of coolant under the car after a normal drive, I located the leak to a razor like slit on the lower radiator hose, The slit would only open when the car and coolant pressure were heated to regular engine temp.

I rolled out the car, swapped out the hose, refilled the coolant, and put the battery back in.

The sap also gave me the chance to drain all of the old coolant. With the system drained I re-installed the new lower radiator hose and added coolant. I started the car and turned the heat on, I was suspicious of the coolant resevior from the day I bought the car, I suspected I wasn't getting any circulation.

I kept my eye on the thermostat, and one hand on the heat vent, I let the car idle, the heat gauge rose above the normal spot but my hand could feel no heat, I shut off the car, carefully vented the resvior tank and added more coolant. Upon opening the tank cap gurgling/bubbles seemed to come up from the hose leading to the engine. The system had also pressurized.

I added more coolant, this time to just above the min line, started the car and did the same, no heat. I popped the hood, opened the cap, the same gurgle/bubbling with moderate power, then added more.

This time I started the car, I gave light acceleration in nuetral bringing the car up to 2000k then 2500k then 3000 for 7 second intervals, I noticed the thermostat would slowly drop when the engine was revving, but climb at idle, the heat was on full blast, nothing.

I then added more, totalling a bit less than a gallon, decided to drive the car slowly around the neighborhood. As soon as the car was operating at regular RPM intervals there was enough pressure to run the low coolant through the system, the heat kicked in! Is this assumption correct? The heat was coming strong now, and the engine temp had stabilized.

I drove for 15 minutes, everything seemed normal. My tires hadn't gone square either. I topped of the fluid when I got home. I also realized that being timid probably cost me an hour! but I guess I'd much rather be timid than make a terrible mistake.

Questions: Is the gurgling suction/venting of the system normal when partially filled?

Is there a better way to add coolant?

I know everyone encourages regular replacement of timing and water pump, should I be concerned with the health of my water pump based on the described scenario?

Now I just need to keep her off the road until it rains a few times! Look forward to your thoughts.

zoltan944

yes, the air in the system will alow boiling and it needs to get out of there. its easier to fill the car full of fluid through the radiator cap and then turn it on with the cap still off and add while the coolant circlulates and when its all full put the cap on and blast the heat, you should have been able to top it off well before operating temp

Granite 944

I remove the bleeder bolt (car level, temp lever at hot), fill till coming out bleeder hole, replace bolt, attach my coolant pressure tester, pump up to approx. 10-12 lbs, open bleeder, bleed off any air, top off coolant (1/2 way between max. and low marks), and haven't had a lick of problem with "gurgles".

Clark's garage has a writeup also.

Gurgling sound is air in system. Must remove......must remove....must remove..............

Older post, butt, having fun anyway! Sure ya got it sorted out by now.

theiceman

The problem you had was no coolant up against the thermostat , this air pocket does not conduct enough heat to get the stat to open, and that was your gurgling sound, this air pocket also stops flow through your heater core.
Sounds like you have it sorted.