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Re: Water pump diagnosous and replacement questions Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 2 May 2005 05:44:23
In Reply to: Water pump diagnosous and replacement questions, lincoln, Mon, 2 May 2005 05:27:27 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Water pumps usually fail when the shaft seal leaks - you start getting coolant out of the weep hole. However, they still keep pumping. I've only heard of an impeller coming free once or twice. Therefore, I'd assume that the problem isn't your water pump.
A LOT more information is needed. What is the sign of overheating? Is it that the temp gauge goes too high, or is it that you boil over? If there is boil over (steam from the engine compartment) but the temp gauge isn't going into the red, I'd first think about replacing the coolant reservoir cap. Also, look around for a loose hose. Anything that can keep the system from reaching full pressure will cause it to boil over at cooler temps.
When does the problem occur? Does it overheat when driving down the road, or only when you are idling, stuck in traffic, or going slowly? If the temp gauge is going into the red when you're going down the road at speed, I would still suspect the thermostat. Yes, even new ones fail. I assume that the system was properly bled. Replacing a thermostat is easy on a 900 - I'd simply replace it if you overhead while at speed. The other possibility there is a clogged radiator. But don't discount a bad thermostat, even if it is new. Here's a test - watch the temp gauge starting from a cold engine. If over a few minutes the gauge just goes up to the red with no pause, it's probably a stuck thermostat. If the temp gauge goes up a bit over 9:00, then drops down, then goes back up again, etc., then the thermostat is operating, and the problem is probably in the radiator.
If you only overheat when going slowly, is the cooling fan coming on? That should cycle on and off when the radiator gets hot. If the cooling fan isn't coming on, then I'd check the relay, thermoswitch, and fan. A lot going on there for a short post.
Lastly, are you using coolant? Is there coolant in the oil? Is there oil in the coolant? Is there whitish smoke from the exhaust? That would be the sign of a blown head gasket, which can cause and be caused by overheating. Not a happy thought.
More info! When does it overheat? How does it overheat (steam, high gauge setting, etc.)
posted by 192.249....
, Tue, 3 May 2005 22:01:02, Mon, 2 May 2005 05:44:23 <-- Viewing This Message
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