Water pump replacement (2.2 NA)

Is it the pump?

• Leaking from the pump. The Z22SE pumps leak from the square or oblong "tell-tale" holes. One owner explains this as the internal shaft corroding and the graphite seal collapsing. It is more likely the pump than the seal on the coolant pipe, though one owner said the pipe seal could also be the cause. See Finding a coolant leak.
• Whining that gets louder. One owner asked about it in 2007. Others asked whether it was the fuel pump instead, so check where the noise comes from first.
• High temperatures. Pumps are blamed for this often, but the threads show it is hard to prove. One garage suggested brittle plastic blades, but the owner's replacement GM pump had no plastic blades, so that is unconfirmed. Check the other causes first. See High coolant temperatures.
• How long they last. One owner with a car at about 175,000 miles believed the pump was still the factory one. Another owner's pump was two years old with about 14,000 miles on it.
• Sealant in the coolant. One owner had a garage add sealant that stopped the leak for a track event, but the hot running continued.

Choose your method: tool or re-time

The workshop information system (TIS) calls for a special tool that locks the pump sprocket to the timing case, so the balancer chain stays in time while the pump comes out. Owners disagree on whether it is worth it:

• Use the tool. One owner says you must use it "or you will have severe engine vibrations". The bonus is that you don't touch the chains. Vauxhall don't sell special tools, so owners buy a copy. In 2010 one said they cost about £40 to £80, another found the genuine tool very expensive. If you only need to do it once, ask around for a loan.
• Skip the tool and re-time. One owner who owns the tool and has used it says not to bother: take the sprocket cover off, let the chain drop and re-time it afterwards. He found it very fiddly to get the new pump onto the sprocket because of the chain tension, and says re-timing is safer and faster. This is one owner's view, and re-timing needs the chain procedure, which isn't described in these threads.
• If you are changing both chains anyway, the tool isn't needed. Another owner suggested doing the chains at the same time if they are old, although the owner doing the pump chose not to take on both jobs at once.
• Check afterwards. After a tool-method job, listen on starting for an odd whine that rises with revs. That owner says it means the balancer chain slipped and is out of time (it happened to him).

Access: clam on or off?

• The rear clam off makes it easier. One owner says that with the clam off it is "a bit fiddly, but otherwise quite easy". Another had his done with the engine out.
• It can be done with the clam on, by several owners. One says it is a pain but possible from the driver's side rear arch. A 2015 report says it can be done without taking off the clam or the exhaust manifold if you can get the car on a lift and work from underneath with the driver's side wheel off and the arch liner out. One garage's method: remove the offside wheel arch cover, undo the engine mount and jack the engine up slightly.
• Supercharged cars are harder: one owner says the charge cooler system gets in the way of removing the thermostat housing, and an aftermarket exhaust manifold makes it a clam-off job. Another owner argued the supercharger makes no difference to the pump itself, so that is a mixed view.
• One owner says the exhaust manifold does not have to come off. Another thought it might for better access.

Outline of the job

This is one owner's outline (2013), confirmed as "about it" by another, for a 2.2 NA with the clam off. It is not a full procedure, so use it with TIS.

1. Take off the exhaust heat shield.
2. Drain the coolant. See Changing the coolant and bleeding the system.
3. Remove the thermostat housing connection and pull the alloy pipe out of the pump.
4. Fit the locking tool to hold the sprocket. Remove the lower of the two awkward bolts first, before fitting the tool. TIS says to do it after, but one owner found his Laser-branded tool blocked the bolt.
5. The upper bolt needs the engine mount undone to reach. Another owner says the one long bolt is fiddly and can usually be got at by taking off the side and front mounts and moving the engine up and down a little with a jack.
6. Unbolt the pump and, once the sprocket is off, it comes out of the bottom.
7. Fit the new pump. TIS says to use a new seal and grease on the rubber seal of the coolant pipe between the thermostat and the pump. A little grease helps the alloy pipe slide into the pump, and the seals can normally be reused (one owner's advice).
8. Refill and bleed.

The same owner practised the removal on a spare engine first, and found it went well. A dentist's mirror would have helped him see into the sprocket hatch.

When he fitted the pump he found a lot of debris around the exposed spindle at the top and asked whether to plug the hole. Nobody answered, so don't treat plugging it as advice.

What garages charged (dated)

• 2010: one owner was quoted about 2 hours labour but the garage took 7 hours, with the clam on, and charged £280, saying there was far more to it than expected. Another had a quote of 2 to 2.5 hours.
• 2014: a specialist quoted about £300 for an NA and about double that for a supercharged car. Another owner said a different garage did an NA for about £300 recently.