I'm enjoying my Memorial Day by replacing the waterpump in my 2003 XKR. I am using an aftermarket with the metal impeller. I'm replacing it because of a slow leak at the waterpump. I'm taking proactive action due to my experience with a waterpump with a plastic impeller in my BMW. The impeller broke from the shaft and before I knew it the car started to overheat; steam comming up from under the hood. Luckily no damage to the head but the overheating did take out my radiator. So, I'm taking care of the pump now to preclude any more serious damage.

I've got everything removed. I've read the threads about the plastic thermostat housing and am thinking of replacing it and the thermostat while I have easy access.

So, I have two questions.

1) What is the torque on the waterpump bolts? I've seen two specs on this forum (can't find them now). One is to a specific torque and the other is to a specific torque + 90 degrees.

2) Did I get lucky by not having a plastic thermostat housing? I looked at the pictures (thanks Gus) of the thermostat housing replacement procedure and I do not see a similar housing on my engine.

Thanking the forum in advance for your support and help.

 

The XKR uses a Aluminum Thermostat Housing.

The Torque is 8 Nm (6 Ft Lb) + 90 Degrees.

 

Small note, there is nothing wrong with plastic impellers (except 97 and older ones). The recommended OAT coolant used now does not contain any silica, which is preferred for protecting metal impellers against cavitation. Now I would not recommend changing coolant (but could be an option, like a HOAT that would protect the metal impeller better), and I also don't want to scare you, but it might be good to check your impeller again after some good miles just to be sure it hasn't eroded. Can’t tell if this is 10K or 100K, it will also depend on engine speeds (so higher RPMs)used.