Kapekele

how can I test my water pump for w210 engine

chassis

Welcome! Please post a photo of the E320.

What is the situation that calls for testing the water pump? Can you describe the behavior of the vehicle?

Kapekele

The engine was over heating. I started changing the radiator coz I discovered leakage, after that I changed thermostat but again still the engine is over heating so suspect water pump

chassis

Are you sure the coolant level is 100% full, with no air in the system? Does your climate control system work properly? Does it deliver full heat at the highest (warmest) setting)?

You changed the radiator, and the thermostat, correct? Please describe your procedure to refill the coolant.

When the engine is running, feel the top hose and bottom hose. Describe the temperature you feel. Squeeze the hoses - are they soft, or firm? You need to get more information.

p.s. Don't burn yourself or cut your fingers off in the running fan, and don't get your hair or clothing tangled in the serpentine belt.

kajtek1

You can get infra-red thermometer and compare temperature of the hoses past the pump. That will take some interpretation to eliminate other things, so next easy thing is to remove thermostat and see if the engine runs cool.
On my diesel the pump had originally plastic impeller, who broke on halves at some point. After thermostat removal I was able to stick my finger into the hole and feel broken impeller.

Kapekele

Yes climate control system works well, I feel the coolant to the maximum line. Then how is the temperature supposed to be for the two horses upper and bottom

kajtek1

When you have car overheating, on well working system the pump temperature and radiator inlet should be both hot, with minimal difference.
When radiator inlet is much cooler - that is indication of lack of flow, what again can be closed thermostat as well.
Than compare radiator inlet and outlet temperatures.
Bear in mind infra-red will give you different readings when you point it to different materials of the same temperature, so play with it a bit before making final conclusion.

fabbrisd1

The water pump is basically a belt driven propeller/impeller - and "water pump failure" most commonly is when the water pump loses it's shaft bearings/seal and "blows"/major leakage - I have seen a "couple" which seize with failed bearings but that will throw a belt or cause a whole-bunch of noise..

Not knowing if you are in US or not - if you had a leaking radiator/so you replaced that - and you still had a overheat/red-zone-temp-gauge and you replaced the thermostat with the correct one - if it was me I would suspect a main fan problem. and/or a auxiliary/electric fan problem maybe too.

Do a google - the main W210 engine driven fan has a internal sealed "hydrostatic clutch" - and with time/miles that engine fan can fail - where the clutch only "softly" locks the blades (rather than "firmly") so with that failed/failing clutch main fan spins/makes-noise - but really doesn't move much air at all thru the engine compartment.

Do NOT cut your fingers off - do a google on how best to diagnose that FAN

Kapekele

yes you said I even changed fan clutch put another one and mechanic confirmed its running well now. What is coming overheart now seem difficult to find
I will get back to the machine for further diagnosis..

chassis

What does the temperature gage show inside the vehicle? Please post a photo. Thanks.

Kapekele

let me post it tomorrow when I run the engine ok

FlatlineEF9

Take out the thermostat and fill up the reservoir, and both coolant hoses. If its not overheating with no thermostat in there, you filled it wrong last time and have a massive air bubble in there. This would happen if you only put coolant in the reservoir, like you stated.