Water pump 6 cyl

[Alan W]

Ok, those of you who belong to the Z3 UK Facebook group will know that the bearing on my 2.8 water pump failed causing the shaft to bend and the viscous fan to self destruct on the shroud and radiator..

On the plus side like think that although the radiator bears some superficial scars l don't think it's actually been holed so that's a relief as it was potentially the most expensive part..

It is ironic that l was going to change the pump thermostat and belts at the end of this season, and with only 57000 miles on my well cared for 2.8 l thought l was being over zealous.. so it just goes to show you!

Okay, l'm not a mechanic but l am willing to give this one a go.. so from what l have read / heard l think l should get genuine oem parts. So that will be water pump, thermostat unit and viscous coupling / fan? I'm also going to change the top and bottom hose whilst looking at it and will be need a new / secondhand shroud.

My question for those who have done this job or know a bit about it is... should l look at changing the belt(s) at the same time? I also think that there is some kind of tensioner and if l replace the belts then l am guessing it would make sense to change this too? Is this a job that is relatively easy?

Please feel free to share your experience / opinions on this..

Thank you

Alan

 

[Alan W]

Oh and do l remember reading somewhere that the water pump bolts can be a bugger because they are steel and thread into an aluminium head? If so, any tips on removal and should l get new bolts for the new pump?

 

[andyglym]

Part of the system needs of special tool, water pump I think (some sort of lever type thing, not sure if it can be done any other way), so I added one to the bill for when my local garage did it. If you want/need to borrow it pm me your address and I'll send it to you. Good luck.

 

[GazHyde]

I changed the water pump on mine when it failed, and was a reasonably OK job.

You need (and I'm sure someone will remind me of something I've forgotten)

• a 32mm spanner and a gripping tool for breaking the viscous coupling with the water pump. Something like this - https://www.ebay.co.uk/itm/381636992574. It's a left handed thread, so you have to undo it "the wrong way"

• A new water pump. We bought the last couple from GSF which have the plastic impellers on them. Discussing with their parts manager he says they are no longer an issue with breaking, but if you can find a metal impellered one then all the good.

• May as well change the thermostat while you are in there.

• New antifreeze.

• Obviously a new fan blade. I bought a GSF pattern one, which didn't last and shattered within a thousand miles. I'd recommend an OEM one from Sopers which is what I ended up doing.

• New belts. You have to remove one of them to do the job, so silly not to.

• Tensioners, again while you are in there and have the time...

Had no problems with removing the bolts, other than dropping one down in to the engine bay. It's not the worst job, just needs a few hours.

 

[Grumps]

Just done all this on mine @Alan W. Fan blade self destructed so decided to do it all. Water pump, fan blade, viscous coupling, thermostat, drive belt, pulley and tensioner. Well I didn't strictly do it all @t-tony did but I was there to help where I could. We didn't have any issues with the water pump bolts, just came out as they should. All the parts were ordered from Euro carparts. They seem of a good standard. The blade was a Miele which is the advised make of you don't want to payout for oem. I'd certainly advise you do the lot as your in there anyway. Good luck with it. I'll help where I can but not to much of a techy myself.

 

[Dino D]

Thermostat housing - not expensive. Mine cracked after doing all the above work. Looked perfectly serviceable, like new so never changed with the thermostats but it just just cracked one day after all the above was done of course..

Do you have an aircon?

 

[Antm72]

There are two thermostat housings on the early 2.8 one you can buy a stat at about £15 the other complete in its housing and closer to £80 the real oem showed my car as having just a stat but it had the later more expensive part

 

[Alan W]

Do you have an aircon?

Yes l do have A/C Dino, why is that?

 

[Aceman]

These are the tools you need and make the job so much easier.

https://www.ebay.co.uk/itm/381636992574

 

[GazHyde]

These are the tools you need and make the job so much easier.

https://www.ebay.co.uk/itm/381636992574

Thanks Ian, that was the exact one I was looking for! I'll update my post with that link.

 

[Dino D]

Yes l do have A/C Dino, why is that?

the AC has an electric pusher fan that comes on when the AC comes on. It also acts as a back up for cooling the main radiator. it has two speeds (fast for when AC is on and can be normal or fast depending on the temp reading in the radiator). There is a switch on the side of the radiator (left side looking at the car) that controls it.

Worth checking this fan is good (spins freely and not noisy) and the rad temp switch works as it should (some including mine were wired incorrectly form the factory so didn't work as it should). I'll dig up the thread on it.
here it is: https://zroadster.org/threads/fan-delete.7136/#post-96729

With just the AC fan kicking at the correct temps the car runs fine without the viscous so a nice back up that's there already.

 

[roadvoyager1]

I did a write up on water pump/thermostat change and fan delete a while back. To add to @Dino D s comment. It is recommended to change the thermostat to a lower temperature version also.
Will find the posting and add link later.

 

[t-tony]

Oh and do l remember reading somewhere that the water pump bolts can be a b***** because they are steel and thread into an aluminium head? If so, any tips on removal and should l get new bolts for the new pump?

Hi Alan, these are a couple of pictures of Dave's old water pump from his 2.8 that we changed on Saturday. It is fitted the front of the block on 4 6mm studs which have 10mm nuts. Also you can see the large rubber "O" ring which seals the coolant in. You may have to gently lever it from side to side to ease it out of the block. This one had been replaced previously we think so was reasonably easy to remove. The "O" ring on the new one was a very good fit and required one person the push the pump in whilst another fitted the nuts onto the studs, the tighten the nuts evenly till its tight up to the block.

Tony.

 

[Aceman]

Tony you may not realise but there are two threaded holes either side of the pump which you can screw a couple of the bolts into which allow the pump to be teased out, much easier than tugging and pulling especially when you get a tough one to extract.

 

[roadvoyager1]

This is the link to the fan delete thread (see post#17 in it for my explanation) https://zroadster.org/threads/fan-delete.7136/#post-135113 .

It also covers the water pump/thermostat and belts replacement, with parts and part numbers we used.

Hope that is of some help.

 

[t-tony]

Tony you may not realise but there are two threaded holes either side of the pump which you can screw a couple of the bolts into which allow the pump to be teased out, much easier than tugging and pulling especially when you get a tough one to extract.

Thank you Ian, indeed I didn't know that. I gave the new pump only a cursory glance to see it was right but didn't notice the screw threads. To be honest the studs could do to be about 5mm longer to aid in the fitting of the new pump.

Tony.

 

[Alan W]

Okay for those of you not on Facebook.. so yesterday l started to dismantle the the car to see what nasty surprises were waiting for me.. well the bearing in the water pump certainly had collapsed big time and the shaft has bent causing the fan to self destruct and trash the fan and pulley and, unfortunately, the radiator.. The plastic pump impellor had also broken in two which is why l am getting an upgraded pump from Germany with a heavier duty bearing and a metal impellor!





Also noticed that both belts are showing signs of wear and one of the tensioner has some play so l'm going to renew those too..

So my shopping list thanks to the water pump is as follows..

Water pump
Pulley
Fan
Fan shroud
Thermostat and housing
Belts X 2
Radiator
2 X tensioner (one of which is hydraulic and expensive)
Top and bottom hoses
5 litres anti freeze
5 litres deionised water

All in all around £600 but no labour costs as l am doing it myself supervised by my mechanic brother

 

[Alan W]

This is the uprated pump that lm getting fton germany which at £28.99 plus shipping ironically works out cheaper than a standard original oem one from a dealer??



And this photo is testament to the condition of my car.. she really is very clean underneath which is thanks to her low miles, being garaged and only being used in the summer months, and a fanatical previous owner.. l only hope l can maintain that regime!!!

 

[Alan W]

Whilst changing the water pump and other bits on my car is proving relatively straightforward, getting the radiator out wasn't because being a 2.8 auto there is a second small rad bolted to the front of the main rad which cools the auto box fluid.. there are two bolts at the top which are easy peasy but one of the two bottom ones is a pig and will be even more of a pig to put back.. it would have been far easier to have disconnected the pipes at the bottom but was concerned about losing the fluid unless someone can give me a top tip workaround?

 

[t-tony]

If you can quickly plug the pipes as you remove them and tie them up as high as possible then you should lose very little ATF Alan.

Tony.