MikeinBloomfield

What you're talking about is the failure of two systems at the same time, the water pump and the monitoring system. Also the failure of the monitoring system is such that it is sending incorrect temperatures, not no temperatures. I suppose its possible, but is really highly unlikely.

And look, the cooling system on these cars is fragile. The coolant tank cracks (my car is on its second), the coolant cap seals fail (third or fourth), and there's a coolant hose connector on the front of the engine that will murder everyone you care about if you touch it (not really, but it does break easily). I'm surprised that the radiators being so far away from the engine doesn't cause more issues, frankly.

In all probability, you've got a coolant leak, like a lot of us have had. Its possible the water pump is leaking but from where the steam is coming from, its probably the tank or the cap. Have it towed to this shop and they'll figure it out.

DBJoe996

Yes, the impeller can come loose from the shaft, the pulley can also come loose from the shaft, and the shaft can break.

MikeinBloomfield

Yes, but then the car would overheat and his temp gauge is showing normal.

Turbodan

get AAA and get it towed.

sauregurke

Yes, this is exactly my fear. My question is if the water isn't circulating, is there any way to know? Because if it's not circulating, perhaps it is possible that the coolant temp sensor is not sensing water coming from the heads, but instead the water which is just sitting where it is, heated up by radiant heat.

For example, if the pump isn't working and there is no circulation of the water in the system, is it possible that the temp gauge is just reading the non-moving water where it sits? Or is there some safeguard against this, such as an oil temp sensor or maybe a temp sensor somewhere in the engine, that would perhaps throw a check engine light? Surely Porsche wouldn't put the faith of protecting the engine from overheating into one coolant sensor...

And one more thing - is it possible that the problem was just a loose cap? Or rather, could a loose cap cause about a gallon and a half of coolant to spill out and steam to billow like in the movies? This happened after a short, warm drive to a drive thru and sitting at idle, about 2 or 3 miles.

wildbilly32

Possible. Check around beneath the cap and look for dried water residue on top of the tank in that area. These caps need to be installed tight. Read that as TIGHT!

ssherman68

I'm dealing with a similar problem. I'm 90% sure it's the coolant tank (it's yellow). Twice in the last few weeks It leaked coolant out below the driver's side muffler after being parked for a while. No steam, not a lot of coolant and engine temps were normal. It acts like it's only leaking when the tank gets pressurized after stopping the engine. The second time I stopped driving it and now I'm waiting for Pelican to send me a new tank. Mine's a '99 and I'm hoping I can do it without lowering the engine.

wildbilly32

My tank started leaking so slowly nothing was even hitting the ground. After driving in hot weather and parking in the garage I could smell antifreeze, but nothing was visible. After some time I started to see dampness on exhaust parts and finally a drip on the floor. When the tank came off it was cracked down the back and the crack exhibited dried water deposits. After changing the tank the smell went away.

ssherman68

Mine only does it when I park it and walk away. Apparently she's shy about wetting her pants.

Weazer

DO NOT DRIVE THE CAR, HAVE IT TOWED!!!

mdsarch

This seems a bit of a “right of passage” with these cars. My story happened on my drive home (Charlotte) after picking up my new to me 2003 C4S from Denver. I had made it to the Tail of the Dragon and pulled over to enjoy the view. I looked in my rear view and saw steam rising from the engine bay. Now I had just sold my 964 so steam was a new phenomenon as this was my first water cooled Porsche. Luckily my insurance cover 200 miles of towing and had it towed to the nearest Porsche dealer. They found that there was air in the system so the air bubbles rose to the top during my spirited driving at the TOD. In addition, there was a slight crack in the expansion tank. I suggest you tow the vehicle to your nearest dealer and have them check out the coolant system and do not try and drive it there. Why risk it? Good luck!

marlinspike

Where are you located? Maybe one of us is near you.

alexandretur

100% - get AAA Plus Membership for $150. You can use them 24h after payment. You will get four 100 miles tows / year and additional services.
You could use them later if you have a flat if you dont trust a 20 yo spare.
It is key when you have an older car.

I am not affiliated to AAA.

sauregurke

Thanks for all of the advice, right now the car is behaving normally. I believe it was a loose coolant cap or a cracked coolant expansion tank because it hasn’t *yet* lost its fluids again. I don’t plan on driving it much until I replace the water pump but it seems safe enough for the drive as the temp gauge doesn’t show that it’s overheating. Once I get it to the garage I’ll get all of its cooling maintenance done; I’ll update if something else goes wrong. Soon enough I’ll have a lift and do all of the maintenance it needs.

P.S.: I’m located near St. Louis.

Weazer

sauregurke, if my experience with the dashboard temperature gauge dissuades you from driving the car, I will be gratified. I'm on my way to meet the family for lunch on a May afternoon when all of a sudden the temperature gauge light starts flashing. Luckily, the restaurant was just past the next light, so I pull in and pop the trunk, coolant reservoir looks low so I go in and have lunch and when I come out I pour in almost two 2 liter bottles of water that I always carry in the front trunk. l get home uneventfully and the next morning check the coolant reservoir and its full of intermix!!! Mind you, the temperature gauge never went past the 0 on the 180. Normally, the needle on the temperature gauge meanders between the start of the 8 and the end of the 0 depending on ambient temperature and traffic conditions. The point is, although the temperature gauge was within the normal range, the damage was done, cracked head and all that that entails. The culprit was a pinhole crack in the coolant reservoir and, but for the flashing light, the temperature gauge was reading within its normal range and I would have done a lot more damage than I did. I never saw a leak, or saw steam, or smelled coolant. I strongly recommend that car not be driven until the cooling system is 100%, but its your car to do with as you wish. Best of luck.