97 Aurora Cooling Problem

OK, before I go blow a couple hundred bucks on a new rad, I'd like to know if anyone else has had a similar problem.

My car overheats, and the heater does not work. I have flushed it a couple of times, and the rad is full.

I flushed it with CLR once, and it did cool properly, and the heat worked again, for a short time. It will overheat at all speeds and at idle, so I know that it is not the fans. I did a compression check, and everything was fine, so I doubt that it is a head gasket. Occasionally, when I punch it, the car will cool for a bit.

So, I am pretty convinced that the rad is hopelessly obstructed.

Also, the rad does not have a drain plug, does it? I had a set of GM manuals for the car, and they said that it did, but I can not locate a drain anywhere--but we all know how easy finding things under that hood is.

Any thoughts to the contrary on the rad being plugged?

Drain plug is on the drivers side, accessed through a round hole cut into the plastic panel that is directly behind the edge of the bumper cover. There may be a piece of foam in the way but you will be able to feel the plug with the tip of your finger. Use a deep 19MM socket. All that being said, I would suspect a bad water pump before a clogged rad. That rarely happens anymore.

what about a sticking thermostat?

First thing I did was replace the thermostat--then, to be sure that wasn't it, I busted the middle out of the first one and put it back in. Definitely not the t-stat.

Then I thought water pump. So I pulled the top rad hose from the intake manifold, where the pump is, and started the motor, and watched the water fire out of it. Personally I have never seen a water pump fail that didn't pump, they just leaked.

I forgot to mention that I checked the obvious first.

I'll check for the drain plug there, thanks! Those big-ass GM manuals aren't much better than the Chilton ones--except for the wiring and A/C. I would have expected that if the drain was hidden in such an assinine place that the GM service manual would have pointed that out.

Oh yeah,....to make the situation worse, the access hole is actually in the crossmember/subframe not the plactic(sorry about that), and if the rad is not placed just right you can't get the socket onto the plug. I went ahead and opened mine up with a die grinder when I changed my rad to make future coolant changes easier.

I am having similar problems with my 97 aurora. I have replaced everything from hoses to the thermasat, the rad and flashed the system many times. It still over heats and I am out of ideas.

If anyone has any suggetions and/or a copy of the repair manual. Please e-mail me at [email protected]

How is your water pump functioning?

Its has been replaced as well. I have replaced everything ( the fans, thermesat, belts hose, water pump,, radator and had it flushed )but the engine or head gaskets. It would run good for a while then back to overheating again.

Cracking around the headstuds allowing superheated exhaust gases into the cooling system. When this happened to mine, it took a year and a half before it got so bad I could'nt go two miles without cooking it. While this was going on there was no loss in power or mileage. Ran smooth and never got coolant into the oil. Check your coolant surge tank for exhaust smell. If in doubt, take it to a smog check station and ask them to insert their smog machine probe into the surge tank to detect gases.

The water pump and thermostat should be working if the radiator gets hot, after the engine warms up. At about 220 degrees, get a flashlight and see if your Cooling fan comes on. If not, you have a bad fan relay, or fan. I think the one on the left(driver side) goes bad first. I believe this is the secondary fan.