When to replace water pump and alternator?

Knock on wood, it would seem that my water pump and alternator are running just fine, but I'm a fan of preventative maintenance. What mileage should they be replaced at? I'm going on about 135k miles, but searching here I've either seen "wait until it dies", or for the water pump, every 100k. Like I said they seem ok, but is there a mileage interval they should be replaced at?

 

Same time as timing belt, if you've got one.

Or, whenever you change the hoses. I just did mine at 200k and it looked basically new, hoses weren't too bad either.

If you've got good coolant and mix it with distilled water, the cooling system should run for a very very long time.

 

I changed the belt at 120k so it's still new, but AFAIK the water pump, alt, and hoses are original but seem perfect.

 

Some mechanics often replace water pumps before they fail. Some shops recommend replacing the water pump while simultaneously making other labor-intensive repairs, such as swapping out the timing belt. A water pump should last 60,000 to 90,000 miles, about the same amount of time as a timing belt.

 

I suppose I might as well get the water pump replaced, but what about the alternator?

 

Typically the WP and T-stat and tensioner are replaced at the same time as the T-belt. It's a shame that wasn't done. You should see signs of alternator problems before it leaves you stranded. My 1st gen 2003 still had the original alternator on it when it was totaled last year and it was on its third T belt and water pump.

 

My alternator has 245,000 so does the timing belt and water pump.

I spend my time fixing other peoples truck so mine gets put off.

 

4cyl or 6cyl? I don’t believe the 2.7 has a tbelt I know the 4.0 doesn’t.

 

V6, when I said belt, I meant the serpentine.

 

i detect insecurity/anxiety

with an infinite mileage
true U might have to replace ANY component on ANY vehicle

i drove 1 of my vehicles 300k & the only thing i replace in the engine compartment
1 battery
water pump

not even the alternator

fix when broken/needed

thatcertainly does NOT have to happen 3:00am when raining
either usually provide warning

good luck

 

When to replace them?

When they are failing. They reveal their failures in more than one way. Water pump when it is leaking.

They can fail at any point even at low mileages so do your general visual inspections at each oil change internal. I always do, it keeps me honest and my engine honest.

The 4.0 has a timing chain gents.

 

Alternator I would definitely keep until it dies, super easy to tell when one goes bad. Water pump I would also wait, but if it makes you feel better you can replace it. Just seems like a waste of money to replace things that are still working correctly.

 

I have original water pump and alternator at 220,000 miles on my 2003. I see no reason to change them.

 

nearing 200k

just have done the belt twice, idler pullies once, but alt and water pump are good.


oh, and did a power steering pump at 125K along with the steering rack.

 

I suppose I should just keep an eye on them as they can last quite a while, thanks for the insight guys.

 

The alternator if it goes out is obvious (no charging of the battery). However I'd keep a close eye on the water pump especially if you have a lot of years/miles on it. If it fails you could fry your engine before you know it. I just junked a 2001 Chevy Malibu because the water pump I replaced 5 years ago froze up the water pump bearings causing it to overheat. Long lesson short, overheating caused gaskets to fail thus antifreeze got into the oil. So watch your water pump especially if it's old.
Better safe than sorry, if you have doubts replace it.