Interested in others experiences - my 2006 XK (4.2 NA) has done just over 100,000 miles.

It's about to be due for a new timing belt / tensioner and since it combines the labour in that area anyway I'm wondering about having the water pump replaced at the same time, which is original to the car. It's always had the specified coolant swaps etc. and the current one isn't leaking or making any noises. Is it better to leave it alone until there's a problem?

On the one hand I'm thinking that's cost effective preventative maintenance. But also, assuming that any failure would be gradual and obvious, I'm tempted to leave it until there is an actual problem. Or is there a risk of sudden failure I should be guarding against?

 

As we speak, at the same mileage, I am having the water pump, tensioner, and pulley changed. Just a while ago I needed an alternator and belt. Why am I there now? The thermostat housing cracked. Now converting to Evan's coolant, because it was 40% during a liquidation here. The book says its 3 hrs. of work to change the pump, but a lot less if you are there. Good aftermarket gear for that area is not expensive. Do your little pulley as well! Contemplate a thermostat housing change. Its a 17 year old hard working piece of plastic. $100.

 

Sounds like an obvious "while you're in there" job.

 

Could not agree more, I while ago had the seperentine belt snap, which meant also removing SC belt. Went with the better be safe than sorry, so did tensioners for both belts, both idler pulleys and as stated whilst you are there had water pump replaced. Existing one was fine, no issue or leaks but again I dont klnow if it was ever changed or replaced and for the few quid it cost and the mechanic was doing the other bits, why not do this following all the Sage advice on this forum.

 

Definitely replace. My 2011 5.0 sc waterpump gave up at 32,000 miles. I was really surprised at how little noise it was making compared to how much play it had developed. At first hearing it I was hoping it was an idler pulley beginning to go due to the noise being so quiet, you really had to listen for it, but unfortunately it was the pump.

 

Yes. Wifes WP gave up the ghost at 18k and replaced by JLR. On my 2015, I replaced it the day it got in my driveway with 26k. Nto sure about the 4.2's but on the 5.o's they use a 3 piece wp that leaks at the joints. Replace with a 2 piece pump for $120ish.

 

Replace the water pump always!

 

Thanks all, confirmed what I was thinking. Prevention much easier to deal with than the cure etc.

Will be off for a water pump, thermostat & housing, belt and tensioners next month!