Z22SE Opinions sought - water pump and cam / balance chains.

[Jonse]

First post here.

I have a 2002 Astra Convertible. Currently sitting on 110,000 kms (about 68,000 miles). The car has no rust anywhere ('cos in Sydney Australia) and is in good cosmetic condition. I am the 2nd owner, wife now uses it to commute every day about 1 hour each way. Previous owners only used it at weekends so it has had a gentle life. It's only fault other than below is missing lines on the three line display.

It has a water leak from the back of the engine somewhere (haven't narrowed down where from yet). Due to the difficulty getting parts at reasonable cost over here. ( A waterpump from the dealer is approx twice the cost of a genuine pump posted from the UK ) I am considering getting the parts in place to change the waterpump, T'stat and all their associated seals including the O rings on the pipe between pump and T'stat. Fortunately I can pick up the tool to hold the balance chain pulley in place locally at a reasonable price, but I am seriously considering just going for a full cam chain, balance chain and tensioners replacement at the same time. I will also probably look to replace all the coolant hoses while I am at it.

I know this may seem a bit overkill but this car is likely a keeper. My main question is it to early to worry about chains and should I just restrict myself to solving the leak for now, or do I just go for it.

I'll be doing the work myself but this is well within my mechanical capabilities, fortunately I can take the car off the road for a couple of weeks if required.

 

[KevinH]

Hi Jonse, and welcome to the site.

The water pumps on the Z22SE's are usually pretty reliable, but if you put your hand underneath it you should be able to ascertain whether there is a slight leak - the water pump seals can wear. There is a coolant drain bolt located at the bottom of the water pump (awkward to get to) and it's worth checking this is tightened sufficiently (20Nm/15lbf ft).

If you decide to install new timing and balance chain kits (which would be prudent) then the water pump holding tool would obviously not be required and the cost of the tool could be offset towards the new chain kits - would also recommend purchasing genuine GM chain kits .

 

[Jonse]

Hi Kevin,

Thanks for your response. I have decided to buy the complete set of chain kits and waterpump and have already ordered the water pump holding tool (Only £21 delivered so no biggie) I can't work on the car right now due to illness but the plan is to investigate in the next week or so - fix the leak if it is easily fixable (so the wife can use the Astra rather than commute in a Land Rover Discovery at about 10 mpg) and then replace the chains and tensioners later in the year.

 

[vocky]

the water pumps can leak from the internal seals, usually they leak oil first.

 

[Jonse]

Still not been well enough to go and investigate where the leak is from. I now have the genuine timing and balance chain kits plus waterpump and various O rings and gaskets on order from Autovaux. I will no doubt now discover that it is only the drain plug leaking or one of the O rings to the pipe to the Tstat. However as the pump and Balance chain kit cost less delivered than the water pump cost from the stealers here I will have them on hand to do the replacement sometime this year.

 

[patricks]

With my water pump the leak was only actually caused by the seal wearing out between the face of the pump and the engine block. I replaced the whole pump not knowing this and the new genuine pump that i sourced from autovaux didnt spin as freely as the old one (so slightly higher fuel consumption with it). So im going to investigate replacing the seal on the original pump and reinstall it. The chain gives plently of warning before its going to die - im also in sydney and i think with the warmer climate over here (oil gets to the chain quicker( they are likely to last longer. I replaced my original chain at 435,000km

 

[Jonse]

With my water pump the leak was only actually caused by the seal wearing out between the face of the pump and the engine block. I replaced the whole pump not knowing this and the new genuine pump that i sourced from autovaux didnt spin as freely as the old one (so slightly higher fuel consumption with it). So im going to investigate replacing the seal on the original pump and reinstall it. The chain gives plently of warning before its going to die - im also in sydney and i think with the warmer climate over here (oil gets to the chain quicker( they are likely to last longer. I replaced my original chain at 435,000km

Once I got my head around the arrangement of the pump (Being a bit different to the norm) I had figured out that with coolant dripping from the rear of the engine and no coolant in oil, the only places it could be leaking from was either the pump to block seal, or the O rings that seal the pipe to the thermostat housing. By that stage I had already sourced the water pump holding tool and was also thinking about chains (I confess to being slightly paranoid about potential for camshaft drive failure as I have two 32V Porsche 928s with belt driven cams) as a WYAIT job, even if 110,000kms is possibly early.

Re your new waterpump being stiffer than the old one I would expect that from any new pump versus a used or well used one.

Hopefully tommorow I'll get my head under the Astra and sus out where the leak is coming from and with a bit of luck the new pump and other stuff will arrive from Autovaux before next weekend.

 

[patricks]

Once I got my head around the arrangement of the pump (Being a bit different to the norm) I had figured out that with coolant dripping from the rear of the engine and no coolant in oil, the only places it could be leaking from was either the pump to block seal, or the O rings that seal the pipe to the thermostat housing. By that stage I had already sourced the water pump holding tool and was also thinking about chains (I confess to being slightly paranoid about potential for camshaft drive failure as I have two 32V Porsche 928s with belt driven cams) as a WYAIT job, even if 110,000kms is possibly early.

Re your new waterpump being stiffer than the old one I would expect that from any new pump versus a used or well used one.

.

The leak is likely to be the pump to block seal as is often the case. The pump itself is a solid unit. The new "OEM" unit will have metal impellers in place of plastic ones and didnt spin as easy which i also assumed was due to newness of bearing - but fuel economy hasnt quite returned back to what it used to. Id actually like a much better bearings like u have in old vinyl turntables - id say this pump robs the engine of a few hp at the very least....

two 928's.... hmmm tasty!!

 

[Jonse]

Well a month and a bit has gone by and I finally got around to getting under the Astra to see what I could see. (I am not normally this tardy but I ended up in the UK for 3.5 weeks - Could have picked up my order from Autovaux myself as I drove within a couple of miles of their place)

The pump is leaking but from the seal between the two halves of the pump.

You can just see the origin of the leak - smaller pink drop above the big pink drop.

So new water pump has to go on. I will probably try and take this one apart once it's off to see why it has sprung a leak where it has as this joint is "factory made" .

 

[vocky]

that is actually leaking from the O ring seal on the metal pipe, which is why it's discoloured next to the metal pipe.

Much easier to do, just remove the thermostat housing and replace the O ring seals, best change both ends - so two O ring seals, part number 90537379

 

[Jonse]

Thats what I thought originally but there is no trace of pink coolant coming out of the metal pipe to water pump connection. Whatever those O rings will be getting changed anyway as part of the water pump replacement.

I reckon the staining nearer to the metal pipe that you can see but is dry and was dry while the engine warmed up is coolant flung off the drive shaft. With the car off the ground it took forever to warm the engine up and obviously no way of spinning the drive shafts at the correct angle to sling coolant around.

 

[Jonse]

Well, finally the pump is out and Vocky was correct the only leak was from the O ring seal on the metal pipe. Although I couldn't confirm that until the pump was out. New pump and seals ready to go in. But am missing one of the O rings for the pipe. So off to the Holden (GM) dealer in the morning - think I will get three just in case.

Does any one know why the WSM says to take the cover off the pump while it is in the car then put it back on again off the car before replacing the pump into the car ? or do some pumps come without the cover ?

 

[vocky]

makes changing the pump easier, but I never bother to remove it

 

[BGTS]

Sorry for "stealing" your topic, Jonse, but I am with a similar problem and your photo is great.
Well, I couldn't see where exactly the leak is but it stained a rag with coolant when I rubbed it at the seals (metallic where it should be just oil - and I don't have coolant in the oil) and in the inner side, where runs coolant in the interior, and also where the metal pipe joins the pump. So, I believe there is an exterior transfer (as in the photo, right?). But a question came to my mind: for what I understand, this is not an easy or pleasant job to do, even if it's just an o-ring that is leaking, so do you, guys, think it is wise to change the pump even if it's still fine? How much mileage / time these pumps use to last?