Apart from leaking, what are the symptoms of the water pump going bad?

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joel

Prayers bring forth enlightenment.

Apart from leaking, there may be noise from the bearing and in some cases you can detect play by wiggling the pulley.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

Note that the tensioner resides close to the coolant pump. A worn bushing in the tensioner may make some noise, so don't confuse it with the pump.

Based on my experience and from what I've read in this forum, you can get about 100-120K mi. out or a typical OEM pump before it gives out completely...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

I just replaced mine a couple nights ago; it was the original and I have about 129,000 on the car. Your mileage may vary.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

Symptoms: White looking deposits from the dried OEM antifreeze, rattling noise from the pump shaft bearings going out, especially noticable at idle. When putting tension on the belt with my hand between pulleys, I could litteraly see the pulley on the water pump move. Otherwise, it is pretty hard to feel play in it with the belt tensioned up. If you want to see if there is play, take the belt off.

Mine only lasted 65K miles, but then my car is a 91. (72K miles now). It never failed to pump coolant, it was just making noise. After examining it after I removed it, I'm not sure if it would have seized, as the shaft didn't bind at all, it just leaked coolant around the shaft seals.

If you do decide to replace the pump, I suggest that you take the time to replace these too: All hoses at the radiator, the thermostat, the auto belt tensioner, the belt, possibly the tensioner dampener (judgement call here. I did it just to be on the safe side, although I couldn't tell if anything was wrong with the old one.) Tensioner adjustment rod (again a judgement call). Idler pulley (judgement call...my time is worth money...the part was only $30), Take a careful look at the fan bearing assembly. This part is not cheap, so I didn't replace it, but mine seemed fine. My fan clutch was not fine, but I fixed it by injecting new silicon oil in it (I don't remember the Toyota part number...search and you'll find the thread).

What I was really struggling with was weather or not to replace the radiator. Mine is the older kind without the metal sleeve reinforcement, and thus is prone to cracking at the neck. It is also at the age when many people have experiened a failure here. I opted to not replace it at this time. I'm planning on doing it this summer, before all the really hot weather.

There is one bolt on the water pump that I think was designed intentionally by sadists. You'll need a wobbly for your ratchet, wrapped in tape at the joint to keep it straight going in....

Good luck with it.

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On the plains of hesitation bleach the bones of countless millions who at the dawn of victory, sat down to wait, and waiting -- died

If you have to do the water pump yourself, I totally recommend getting the Snap-On FLXM13 wobble extension 12-pt socket. Although it didn't let me skip a bunch of steps like some other users, it did make getting at the water pump bolts a LOT easier. It's described as a "GM Distributor wrench" or something, but you'd think it was specifically made for these water pumps by the way it works.

i have been reading posts about R&R water pump, it seems work is really pretty much involved, and like opening a can of worms where parts inevitably have to be replaced.

I will have to replace my radiator so I believe it could be a good opening to replace my water pump.

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joel

Prayers bring forth enlightenment.

It is pretty involved, but it's doable with patience and the right tools. As for the other parts you might need to replace, you don't really know until you start the job, so you might want to be prepared to have the car out of service for as long as it would take to order the second batch of parts.

The pulleys (idler, fan bearing bracket) you can tell by spinning and wiggling with the belt off. Noisy or loose ones come out. The belt tensioner, you can tell when you take the belt off - if the pointer doesn't move as you tension/untension the device, it's probably shot. Or if the adjusting rod has hit the limit of travel. Belt - they can run for a long time in pretty terrible shape, but you might as well if it's starting to crack. Thermostat - might as well. Hoses - if they are older than about 6-8 years, or starting to show signs of age, cracks, etc., yeah. I don't know if I would replace the tensioner adjusting rod, mine is original and it has 270k miles on it and it seems to work fine.

It was indeed a very involved DIY project. I spent a good eight hours R&R the darn thing on my 1989 190E 2.6. Ended up buying a 13mm swivel quarter drive socket and a 4 inch flexible extension at Sears to aid in getting at that forward lower mount bolt. A third of that eight hours I spent was trying to get to that one bolt.
I was having intermittent temperature rise indication, not quite overheat; then I placed a blade end of a screwdriver to the water pump and listen with my ear on the handle end, lo and behold, the chattering noise was very audible.
Although much laborious hours were spent, the cash I saved from having it done at a shop made every effort worthwhile.

I assume all work is done by just hand tools, right? No compressor/power tools?

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joel

Prayers bring forth enlightenment.

Yes, you can do it with all hand tools. If you don't have a breaker bar, I would strongly suggest getting one though. Also liquid wrench or some penetrating oil. Be prepared for seized bolts.