Using way too much coolant [Archive] - SaabCentral Forums

: Using way too much coolant


Stefano
27th September 2011, 05:47 PM
I have been adding some coolant in my '96 Aero for about an year. It has gone progressively worse, up to the point when it needs a liter every couple of days.

The problem is, I have no idea where the water is going. The oil is clean, I have no smoke out of the exhaust. No visible leaks from the coolant hoses. No leaks under the car. The expansion tank cap is well tight. If I turn on the heating, the windscreen doesn't fog up. Could it be the water pump? It's the only part of the circuit that I can't inspect closely because of the A/C compressor on the top of it.

Other thoughts...?
Thanks.

WSW
27th September 2011, 07:31 PM
heater core maybe

Thats definitely odd, are you sure its not leaking from anywhere?

Superaero
27th September 2011, 07:58 PM
Manual transmission or automatic?

Automatics have an oil cooler inside the radiator which, when it fails, leaks coolant into the transmission! No sign of coolant outside because it all ends up in the transmission.

The water pump is a possible candidate. You can see the weep hole by looking up from under the car under the AC compressor, the water pump is right there next to the oil cooler. Usually when the water pump seal fails you get coolant on the oil cooler pipe where it often evaporates without hitting the ground.

chengny
27th September 2011, 09:05 PM
Radiator leak - tank crack or failing seam at the tube sheet/tank joint. Only opens when hot and the system is at operating pressure. Air flow from the fan blows away all traces of lost coolant. The fractured joint closes up when the engine cools so no coolant shows on the garage floor.

Check the lower corners of the radiator immediately after shutting down a hot engine.

Just a theory - but I have been fooled by this situation before. Looked everywhere but the most obvious place (radiator). It is weakest link in the coolant system, especially the aftermarket ones.

Stefano
28th September 2011, 01:51 PM
It's a manual.

I can see no leaks anywhere: the only part where I can't look is the water pump. I'll findo some time this weekend to lift the car and have a look from underneath.

In case it wasn't the pump... what's the general consensus about Bar's Leak and similar products? I know it's the wrong way to properly fix things, but this is a 16 years old car with 250k kms, and there's no point in doing a repair that will outlast the rest of the car.

Superaero
28th September 2011, 07:27 PM
Bar's Leaks works great as long as the leak is seepage rather than a pressure leak.

I have fixed my heater hose seepage several times with Var's leaks in two 9000 cars. You need to refresh the Bars Leaks whenever the coolant is replaced.

It is officially a fix, even car manufacturers use the stuff, it is not a band aid fix.

Stefano
9th October 2011, 11:53 AM
Turns out I actually did have a leak, and this is what I found after tightening the fastener, then driving a few days with no water consumption, then removing the hose and trying to refit it again....

http://img.photobucket.com/albums/v147/steisan/IMG_1196.jpg
http://img.photobucket.com/albums/v147/steisan/IMG_11991.jpg

I hope the image is clear: it's where the thermostat-radiator hose meets the radiator: the fitting on the radiator just crumbled to pieces.... :)
So, now off to look for a new water radiator.
Are they all the same for all 9000s? I see some are listed for automatics, other for manuals, some are for CDs... where's the difference? do I just buy the cheapest one for a Turbo? I see some have a hole for a temp sensor, and some don't... I don't need it. My car is a manual BTW.
thanks.