Water pump and thermostat

[s2driveruk]

thanks guys, useful - i'll get the kettle on then

[mcandmar]

Vertical, other wise it restricts flow.

[johne]

I don't believe it matters but you could argue it should be vertical so the water returning from the heater connection flows directly onto the temp. sensing part of the thermostat.

What's more important is that your thermostat has no jiggle pin in it or any small cut-out in the edge of the sealing disc like some "Flusser" brand ones do. Any cut out might make the system easier to bleed but it'll make the engine run cold in the winter and that's not good - I fitted a new thermostat like that and had to do it again

Thermostats vary in opening and closing temperatures quite a bit. Before you fit the new one it's worth putting it in a pan of water, heating it and seeing what temperature it opens and closes at - the closing temperature dictates what temperature your engine will run at.

John

[s2driveruk]

hmm, just about to change my stat, anyone confirm the orientation of the bridge on the stat for the 3b...horizonal, vertical or any other?

[UrS4boy]

What do you mean by the open side?
It should be fitted like this

Not *wanting* to muddy the waters (so to speak) but the manual for the AAN (basically the same as an ABY) (but different that a 3B) says that the thermostat should be like this:

[s2_wot]

hopefully that'll have it sorted for you.

[jamie9048]

Well I must be the dumbest bloke ever.

Ive removed the aux rad flushed the main rad, sniff tested for a sus head gasket, changed the thermostat, Ive removed the timing belt and water pump and replaced.

all to find out why my car was chucking its coolant out and running hot.

do you want to know why, after all Ive done it was running hot?



as they say a picture speaks a thousand words...

[2226]

Airpocket

If you have an airpocket or airlock at the thermostat area there won't be hot water to heat the thermostat and it won't open. Make sure all the air is out of the system - did you use the brass bleed nut on top of the radiator to let air out after refilling?

[johne]

which brings me onto the old belt which was slack on the pump side you could twist it 90 degrees easily surely it should be tighter that

When cold that's how the tension should be.

if you remove the top from a normal healthy car would it start steaming and boiling over?

Yes, that's exactly what it'll do and should do.

John

[mcandmar]

The pump with the slotted holes for is 7A/3B application, belt tension was adjusted by the position of the water pump. On the later ABY/AAN engines they moved the belt adjustment to the idler pulley.

Overflow tank should be airtight to allow the system to pressurise, without pressure the water will boil. Your symptoms do sound like a restriction somewhere, personally i would remove the radiator and back flush it until the water runs through nice and clean. Then fill with boiling water to ensure the core dosent have any blockages.

[jamie9048]

Right Ive stripped the front from my car have bought a good quality timing belt and tentioner and new water pump. the new pump is ok looking but the impella is plasic,



removed the old gear from my car expecting to find a fooked plastic impella would you credit it its impella is metal and of much higher quality then the new one the new one has slotted holes for belt adjustment which brings me onto the old belt which was slack on the pump side you could twist it 90 degrees easily surely it should be tighter than that!?




so I`m taking the pump back the morn looking at getting a higher quallity one made from metal

the thermostat is sitting correctly see pic.



so my question is what the fooks gan on why is my car steaming the bottle should I change the bottle top?

if you remove the top from a normal healthy car would it start steaming and boiling over?


should I remove the aircon rad the pump is U/S any way

[jamie9048]

Oh sorry did`nt read it properly I`m going to do the water pump and belt any way for peice of mind and I`ll check the new thermostat

[chezz]

Read my post again mate...you are assuming the new stat is opening at an earlier temperature than the old one when it may be a remote possibility that it is no better than the one you have just removed. Just because it is new does not mean its operating as it supposed to...I'd be inclined to test its opening temp and remove it from the equation.

[jamie9048]

new thermostat fitted

[chezz]

Ive spent the day changing the thermostat it opened at close at boiling point, but was ment to open at 86*c.

So I was confident I`ve fixed the car only to fire up and find that it still runs hot I wonder if the water pump is working correctly if at all?

The bottom hose from the thermostat is cold as well even though the bottle is steaming hot the guage is saying 100 but the pipe is cold it has collant in it and is bleed.

on the bottle should I see coolant being pumped in at the top?

Is the new thermostat opening at the correct temperature?...I'd check it and eliminate it before pulling the pump out etc.