1985-1998 [Subscribe to Daily Digest] |
 | [Main 9000 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: testing the water pump Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 23 Sep 2002 12:12:39
In Reply to: testing the water pump, tracstarr, Mon, 23 Sep 2002 08:50:44 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The common failure for a water pump is for the seal to leak. This is noticable because there will be coolant dripping out of the weephole on the bottom of the pump. Not easy to see on the 9000, but doable. The seal leak is a slow, progressive problem, and doesn't affect overheating, not unless you've leaked out all of your coolant.
Otherwise, water pumps don't really fail in a way to cause overheating. That would require the impellor to actually separate from the shaft or otherwise stop pumping. You'd notice this because the engine would overhet VERY quickly, even at idle. I've heard about a water pump failing with a loose impellor once, but I've never seen one. Somewhere between very rare and 'it never happens'.
If you're overheating, I'd say it probably isn't the water pump. First and foremost is a stuck thermostat. If it sticks CLOSED, then hot coolant from the engine can never make it to the radiator. The radiator stays nice and cool, and the engine overheats. The radiator fan won't come on, because the fan only comes on when the radiator gets hot. This makes sense, because the fan is there to cool the radiator, not the engine.
Since you overheated at highway speeds, you had plenty of airflow over the radiator. The fan is really there to provide airflow over the radiator when you're stopped at a light or going very slowly. So it probably isn't the fan.
If your thermostat is more than 2 years old, then replace it. It's a moving part (or possibly in your case, no longer moving) and it wears out. Of course, do a few checks first - Is there enough coolant? How's your oil level? Low oil can cause overheating. Make sure your serpentine belt is OK, because that drives the water pump. But chances are good that's OK, otherwise you'd have no power steering or alternator. But check anyway.
There is a remote chance that you've got a head gasket problem, as that can cause overheating. Of course, overheating can cause a head gasket problem. But first (and inexpensive things) first - check coolant and oil, and get that thermostat replaced. Then see where you're at.
Good luck!
posted by 192.249.4...
, Mon, 23 Sep 2002 12:12:39 <-- Viewing This Message, Mon, 23 Sep 2002 15:10:29
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
