I had my water pump on my 03 VIII give up last week (it went in less than 30 minutes; but it didn't overheat, just leaked a LOT). I gave the car up for a shop to do the swap.

Things seemed ok at first with the repair, but I'm seeing the car get rather hot at highway speeds. As soon as I slow down the car cools off quickly. Is it possible they put in the wrong pump (one from a regular Lancer)?

 

hmm. thats odd

 

You replace thermostat as well? Did the shop "burp" the coolant system? Have you felt the upper and lower rad hoses to see if there exists a large temp differential? Need more information... But if your car can idle for extended periods without overheating I'm pretty sure it's not your water pump, and you need to look elsewhere.

What you are reporting is normally the opposite of what happens. At highway speeds there is normally sufficient airflow to keep the temps down, but slowing down or sitting in traffic will cause heat soak and overheating.

 

The thermostat was not changed, tho that did cross my mind as a cause. I also have thought about the shop not burping the system, I'm waiting for the car to cool down so that I can open up the radiator and see what's going on there.

This just started so I haven't had any time to mess with it.

Is a thermostat an easy thing to get locally or will I have to order it?

 

Is a thermostat an easy thing to get locally or will I have to order it?

Order or dealer part.

 

The Auto Zone down the street has the part (brought from another store); hope not to get it taken apart and it isn't it. If so I'll live without it for a while.

 

Change your thermostat and make sure all the air is out of the cooling system. Fill it up after changing the thermostat and let it run till all the bubbles burp out of the fill neck

 

I tried that route and ended up with a thermostat for a Lancer. It looks the same but is about a third smaller.