Water Pump Failure - advice please

[ESDavey]

My Griff 500 '98 34k miles has had the temp gauge at 90deg. Its been spitting out water but no major issue. However, its got more serious :

1. 1 There is a metalic grinding noise which just started today. I dont know the exact source but suspect the front of the engine
2. 2 Temp 90deg, fans on but I can remove the blue cap from the expansion tank with ease - no pressure, hiss or steam

I'm thinking I may have a water pump failure which would account for the noise & no pressure. Anyone got a view please ?

If the water pump is dead, I assume I cant even drive it to the garage. All agree or would you risk a 5 mile drive ?

Edited by ESDavey on Wednesday 30th May 15:55

[jeboa]

I wouldn't risk it, if it seizes it could throw the belt - if it gets any worse the circulation would be further reduced and the temp sensor isn't a good indicator as it's only measuring at that point.

[Podie]

Hang on, it's been spitting water and you continued to drive it?

Certainly get it recovered...

[ESDavey]

shame the search engine on here is broken as I'm sure this is a common topic !
Been thinking, I could slacken the belt to isolate the alternator & water pump. Run the car for 5 secs to be assured its one of these components which is making the metalic noise. Good idea ?

[carsy]

Ye give it a go.

[peaktorque]

ESDavey said:

My Griff 500 '98 34k miles has had the temp gauge at 90deg. Its been spitting out water but no major issue. However, its got more serious :

1. 1 There is a metalic grinding noise which just started today. I dont know the exact source but suspect the from of the engine
2. 2 Temp 90deg, fans on but I can remove the blue cap from the expansion tank with ease - no pressure, hiss or steam

I'm thinking I may have a water pump failure which would account for the noise & no pressure. Anyone got a view please ?

If the water pump is dead, I assume I cant even drive it to the garage. All agree or would you risk a 5 mile drive ?

The water pump doesn't create pressure, just flow, the temperature of the water is relative to pressure.

If there is no pressure, then the cooling system is not holding it. This could be due to a faulty blue cap (it is a pressure relief valve as well) - finding an escape of pressure shouldn't be too hard, as you will notice steam, where is it spitting water from?. The lower the pressure the lower the boiling point of the water/coolant.

The noise could be traced to the water pump and indeed could be the source of the lost pressure via the shaft seal. Best way to confirm this would be to remove the belt , which is a 2 second job and you don't even need any tools, just a good push on the tensioner - and spin the pump by hand.

[ESDavey]

Good idea - just removed the belt & spun the alternator (smooth, tensioner roller & fixed roller all appear to spin freely. The water pump makes a noise (like a 50's police siren !)when spun slowly but give it a good spin & it sounds smooth.

Water is being lost via the blue pressure cap. Its 2yrs old. I will try a new part, think its VW origins. Anyone which VW make/model please ?

[ESDavey]

Just run it up in the garage. Water Pump is working fine, thermostat opening & fans cut in. Temp sat at 90deg and no water was lost out of the cap. Maybe I dont tighten the cap up enough after checking the coolant ?

Still puzzled though as to why there is no pressure in the expansion tank - again at 90deg with fans on I can remove the cap with no hiss or hint of pressure. Is this normal ?

(I will start a 2nd thread re metalic noise)

[Loubaruch]

Be very careful opening the cap when the engine is up to temp! You may get a very nasty shock if the coolant suddenly backs up. And a nasty scald.

Check the rubber hoses and the expansion tank neck for blockages this may help:

http://www.bertram-hill.co.uk/Pages/TVRGriffith.as...

Edited by Loubaruch on Wednesday 30th May 19:28

[ESDavey]

Thanks Paul, I have replaced all the original hoses with silicon but will pull the swirl tank overflow tomorrow & check all is good.

[paulathome]

You might want one of these too.
http://www.famousfour.co.uk/new_parts/part_page.ph...
A gasket as well.
Hope you sort it.
Paul.

[ESDavey]

Sorted the water pressure issue ... I had a duff Blue Expansion cap. Purchased a genuine VW part and cooling system now pressurising as expected & no water loss. For reference, the VW part number is 443121321.


The cap on the right is the new part & correct for our cars.

I've also found the reason for the Metalic noise ... will update the other thread