Lousailor

Well, it seems like I had a good run for a while. I was out of town for nearly a month. Drove the car around town for a couple of errands and no probs. Sunday went to go get gas and I heard a clunking that was speed dependant, but only with the clutch engaged. So parked it, until yesterday. Picked up the rear - no loose axle bolts, or anything else on the drivetrain. Tested it and the sound was gone. Drove it to work today (65-75) no probs. Almost made it home and the temp gauge starts climbing to the top. Thing pegged out and fluid spewed from the resevoir overflow. Once I got it parked and hood open steam was coming out and you could hear the motor gurgle. I got it cooled off, but haven't tried to start it again. It's been about 9 months since I had the belts done and changed the thermostat. It was very cold while I was gone (below freezing for many days), but I use 50-50 orange coolant. Any ideas on what may be wrong? I've never changed the water pump, how do you check if it's bad? I had something similar happen before when I lived in SoCal and eneded up just pulling the Tstat for a while. Thanks

George Boss

Happened to me on another car, never on my Porsche. The water pump usually has a built in feature that will make it "leak" coolant out of a purpose-built bleeder. That's not to say that in your case it could be defective (it does happen). Have you done a pressure check to make sure there are no leaks? Also, I don't know about the "orange" coolant, but I assume if it's chemically similar to the other ethyl-glycowhatchamacallit, there's shouldn't be a problem. If you don't have a leak, go throught the cooling system systematically. Thermostat (just because you changed it doesn't mean it's OEM or that it even works right), cooling fan (does the switch turn on? This was the problem on my other car with the cooling problem) and lastly, coolant quantity (make sure your reservoir's intake tube isn't blocked by some foreign particle).
I know on our cars, the fan switch tends to go. I don't want to mislead you by making you look at only that aspect before you examine everything else.
Let me know how you make out. Good luck!

Lousailor

Yeah, I should have made a point that when I pulled over, the fans were both on high trying to cool it down.

Bill

Probably the water pump. These are one of the known maintenance items, with a short service life. Usually last around 30k miles. Remove the belt cover and look for a water trail at the bearing housing, on the pump. Or like suggested above, have a pressure tester hooked up and look for a water leak.

Dave951M

It's not unheard of for rebuilt pumps to fail quickly. In the process of rebuiliding, the impeller is removed and reinstalled. I've seen the impeller come loose on rebuilds. but the usual failure mode is a lead through the weep hole in the impeller shaft bushing. I'd think it's your waterpump.

davearm

I have had a loose expansion tank cap do the same thing. Boiled out a lot of coolant.

josephsc

It's probably the waterpump, but just to add one more possibly -- when this happened to me a couple of years ago, it turned out to be the headgasket. Any sweet smell from the exhaust?

Roy LaZelle

I had a boil over problem last summer that turned out to be caused by <drum roll> the rubber gasket on my coolant pressure cap, and a snug (but not tight) hose clamp. This was pointed out to me by the radiator repair shop when I inquired about getting the radiator cleaned. He looked at the pressure cap and said "here's your problem". The rubber gasket had spread which covered the pressure relief hole, causing over pressure condition, which leaked out under the snug (but not tight) clamped hose. It sounded like a reach to me, but after tightening the clamp and replacing the coolant pressure cap, I haven't had any problems. --Roy--