Contour Enthusiasts Group Archives Forums General Troubleshooting Mechanic says waterpump ius fine, BUT....

OK, here's what's going on with my '96 2.5L Mystique..

I was driving the car to work, which is about 3 KMs from my home and when I arrived I noticed the temp gauge going into the red. I shut down and checked the coolant and saw the overflow bottle was full so decided to let it cool down. It being winter here, it cooled down fast so I drove the car back home (gauge went to the L just as I got home), I also noticed there was no heat(it's cold outside).and took a look at it after it cooled down again. Belt was broken so I put a new belt in and started the engine. Gauge went to the L within 15 or so minutes of idling and NO heat. Replaced the thermostat. Same thing. So I replaced the waterpump with one from the wreckers. Looking into the inlet part of the pump, I noticed the impeller on my old one was black (didn't see any shattered vanes or cracks but bearing felt loose) and the one from the wreckers was white. Same problem. Took the car to the mechanics and he flushed the system, changed the thermostat and temp sensor and charged me $280 after he said he couldn't figure it out. I asked if the waterpump was working and he said yes. Said it might be a head gasket leak but he couldn't say for sure. There's no white exhaust (other than normal condensation. It's COLD out), hand under exhaust pipe gets a bit damp but doesn't smell of antifreeze, no sludge in the oil cap. Took it to another mechanic and he said the same thing. He said pump was fine as he felt the upper radiator hose get hot after the thermostat opened. Once I got home and let it cool down, took out the thermostat and put the housing back together and then I pulled off the heater hose that comes from the bottom of the pump and started the engine. No flow or VERY little trickle coming out at the other end. I blew into the hose going into the waterpump and a stream of antifreeze shot out the other heater hose. I'm thinking the mechanics are idiots. Neither did a compression or leak down test.

So I have no interior heat, car overheats within 3 KMs, no steady stream coming from heater core hose when running. If I idle, gauge hovers around the A L part. If I drive it it will go higher. Before the belt broke, it never went past halfway on te temp gauge.

Is it the water pump for sure? Blown head gasket? Any other way to tell if it's actually the water pump?

Thanks in advance. :-)

Welcome .

Is the pulley for the tensioner working? Is the tensioner within limits?

Check for air in cooling system. May have to massage the upper hoses and leave the recovery tank cap loose while idling or driving a short distance.

Could be a bad water pump from the junk yard.

Do the cheap test for headgasket leak.
Here is a cheap quick way to test the headgasket.
Fill antifreeze to the brim on recovery tank (leave cap off). Remove all spark plug wires. Remove all but one spark plug and have someone crank the engine. If the antifreeze bubbles over, there is leak from that portion of the engine (or cylinder). If not, go to the next cylinder, and then the next.... Note, it could be more than one area or more than one cylinder. Good luck.

Tensioner is fine. I lubed it with some light duty oil. It is keeping the belt tight and I can see the pulleys turning.

As far as I can tell, there is no air in the system. The mechanic totally flushed the system. I also drained some coolant, and re-added more when I pulled the heater hose out. When I blew into the heater hose, it didn;t feel solid, it felt like it was sputtering. After I put the hose back together, I felt some heat coming out of the heater vent but it went cold again.

Interesting way of testing for the gasket leak. I'll try that when it warms up here in Canada.

I am starting to think I got a bad pump from the wreckers as well. Reason I didn;t get a brand new one is because at the time (Just got laid off) I couldn't afford a new one at the time. The wreckers gave me a complete unit with the hoses still attached, so I didn't check if the impeller was ok or not spinning. I just notice there's NO flow at all when the engine is running. No flow felt in the upper hoses even when the engine is revved up.

I was going to say the engine cooling fans are not on, but you would have (a lot of!) heat, if your pump worked. Can't hurt to check they are running (they should trigger at M on the temp gauge). Make sure there is a plate in the housing behind the pump, it's stainless steel. The white impeller pump usually is the good type, there is also metal type (delco, autozone). You can change the pump without pulling the whole housing. The waterpump is the most common problem with the cooling system on these cars.

NO, the fans work fine and come on at the right time.

A plate in the housing behind the pump? Not sure what you are referring to. Do you mean _inside_ the pump?

When I tried to take the old pump off, 3 of the bolts holding the impeller to the housing broke, so I ended up taking the entire housing off (3 long bolts).

Looks like I'll have to take the pump off again to check everything and put a new one in and hope that's the problem. Just wish there was a way I can check if the pump is actually pushing the coolant through.

One person suggested I fill the expansion tank to the top and run the motor and watch for bubbles which would also indicate a head gasket leak. I tried that and didn;t see any bubbling.

You know everyone keeps saying water pump, and I a no contour expert yet but I think you might have a bad thermostat. It keeps the coolant in the motor until it heats up and then opens up to let it circulate to your radiator and heater core. You should check it before you take off the water pump again. Take it out and take it in the house. I put them in a bowl of really hot water and visual look to see if it opens.
Someone please correct me if I am wrong.
thanks Joe

A stuck thermostat with a good waterpump will still prolduce heat from the heater. With no heat from the heater the strong indicatio is that the waterpump is not pumping.