Water pump - opinions please

[widdowson2008]

I'm not 100% convinced about the pocket of air in the pump spinning it up perhaps causing a rattle.
Don't know myself either, but the link Geoff put up suggests '...noise and damage....'
Firstly would a pocket of air not be dissipated into bubbles as it was drawn into the pump? Agree
Reduced mass of the bubbled (cavitated) coolant may cause the pump to spin quicker (internal pressure must alter also)
Technically yes because for a given throttle position, if the pump is pumping air instead of coolant, there is less energy used and more available for driving, which in turn would cause a slight increase in road speed, causing the engine speed to increase and hence the pump to rotate faster.
Practically, this increase in speed would not be quantifiable. The pump speed is totally governed by the drive belts (engine speed).
But surely this would be VERY quick? Not enough to make even a mason alarm adjusted gauge shoot up?
That's the bit I don't get cos this Bongo gauge (unmodified) shot up, and then back down when the rattle stopped
how long has the bongo been in this country?
Don't know
Do you know what coolant it had in it, and what coolant is in it now?
Red stuff - before and after (I think) Perhaps the owner could advise.

[widdowson2008]

Not done one of these for a while, and Ady can NEVER remember which way round the pump rotates, so, here we go.
Hope you understand the flow

IN flow is from the thermostat
OUT flow is to the engine (first port of call is the engine oil cooler)

[jaylee]

If i stare long enough... I AM the pump!!

[Northern Bongolow]

no wonder its overheating if all the coolant goes into that little hole .

sorry steve

[bigdaddycain]

Not done one of these for a while, and Ady can NEVER remember which way round the pump rotates, so, here we go.
Hope you understand the flow

IN flow is from the thermostat
OUT flow is to the engine (first port of call is the engine oil cooler)

Yeah! Now that's good! (though i'm now ever so slightly dizzy)

[haydn callow]

No antifreeze? Couldn't say. Would no a/freeze create this sort of marking? I dunno

Hi Steve, i've only just re-discovered this thread, i'm about to read the rest of it now...

I've never seent the innards of a pump "in the metal" as it were... I suggested no antifreeze as the inner chamber looks like it's been stained by rusty water. (maybe they all look that way after a while? Dunno!)

Hi Ste
Not stained as such, more like a coating - scratches off easily back to base metal. Very similar to that cylinder head I chopped up recently.

I think you will find that is the protective coating laid down when new coolant is introduced. This coating should not be disturbed/damaged as I understand it protects the internals from errosion caused by cavitation bubbles.......this coating seems much more substantional from Red long life coolant.

[widdowson2008]

I think you will find that is the protective coating laid down when new coolant is introduced. This coating should not be disturbed/damaged as I understand it protects the internals from errosion caused by cavitation bubbles.......this coating seems much more substantional from Red long life coolant.

Could well be Haydn. Can't see any damage it could cause by leaving it (rather than cleaning it off). Probably does afford some sort of protection. Dunno. It's a very similar coating to what I've seen on some old thermostats I've tested - that brown/bronze sort of colour.
Could the colour be heat related do you think? Reason for asking is that whilst some stats I've tested are this colour, others have been as clean as new.
Or maybe it's just a particular coolant that leaves this deposit.
.......or pehaps I'm asking too many questions. (that's what happens when you are ignorant)

[haydn callow]

I don't think it is at all heat related....I say this because when new "long life" coolant is introduced at the same time as a LCA is fitted the sensor screw also picks up this "coating" which causes problems.......When a LCA is fitted to a established coolant system this coating does not happen....I deduce from that .... new coolant lays down a protective layer and when it has used up this property "once it's used , it's used"..... This suggests that if a new water pump or cylinder head is fitted then new coolant should be used and not reclaimed stuff......the water pump in particular could suffer cavitation damage....but I suspect many other bits where a "vortex" effect takes place.


So many thoughts but no real proof.!!

[g8dhe]

When I was looking up what Steel Seal was I noticed that it was mentioned that Sodium Silicate was also used in coolants to act as an inhibitor coating the surfaces, just had a check and yes its also mentioned in Wikipedia http://en.wikipedia.org/wiki/Engine_coolant
my guess (just to add another one ) is that is what the coating is, it won't have under gone the glassification that makes Steel Seal close off a leak (needs higher temperature) but the silica deposited on the surfaces will certainly protect them from corrosion.

[mikexgough]

Car Plan Premium Red contains no silicates,borates or phosphates.... as for other coolants I can't vouch for them, Tetrosyl e-mailed me (one of the chaps in the know there) to confirm the above.
FL-22 which is Mazda's coolant is pre 2006 a Blue coloured G12 OAT type and 2006 on (same name but) now coloured Green and is a G12+ HOAT type just to add to the thread....

[widdowson2008]

Hi Mike
I think the silicates Geoff is referring to are in the Steel Seal, not the antifreeze.

[g8dhe]

No they put the silicates in the Anti-freeze as well to act as the corrosion inhibitor.

[widdowson2008]

oops
Ya learn summat everyday.

[haydn callow]

they are included in many types of coolant/antifreeze

[haydn callow]

beat me to it