Help: engine overheating

[kildair]

Would be grat eful for your advise. I have a 1997 E200 auto and do a daily round trip to work of 120 miles.

A few days ago, the radiator warning light came on and bascically I have had to add water about 1-1.5 litres daily.

I changed the viscous coupling fan 2 years ago.

Advise

 

[Dec]

When the radiator warning light comes on, the water level has drooped in radiator so you must have a leak somewhere, on dry ground run the engine for halve an hour or more, switch off engine for safety and try to trace the leak, it must appear somewhere. Use paper toweling, wiping around every likely hose and hose connection, radiator ect.

Dec

 

[kildair]

Thanks. Is there anywhere I ca find pictures/ diagrams of the hosing from the radiator? And how do I know if it is a waterpump or viscous coupling fan issue?

 

[Dec]

Put your VIN number in here...http://www.detali.ru/cat/oem_mb.aspand click on the link at the borttom of the page that appears. VIN number is on bottom, outside of windscreen.

Dec

 

[MB TECH WARRINGTON]

Thanks. Is there anywhere I ca find pictures/ diagrams of the hosing from the radiator? And how do I know if it is a waterpump or viscous coupling fan issue?

tha fact that you are asking these questions indicates that maybe you should let an expert look at it for you, no offence meant,

 

[brandwooddixon]

The fact that the radiator warning light has come on indicates that you're losing coolant.

Have you checked all hoses and joints for leakage - including the radiator?

What does the temperature guage read?

Does it look as if you're losing water through over pressurisation of the system?

Have you done the basic checks for head gasket leakage? Even so this cannot be ruled out.

Check your viscous fan coupling by trying to stop the fan with a carrot, even if it had gone your vehicle probably wouldn't overheat if it is moving (you can always put the heater on full blast to help cool an overheating engine).

Are there any odd noises eminating from the front of the engine? A common water pump failure is due to the impeller coming loose indicated by a rattling noise.

 

[wireman]

If you cant see where its coming out take a good look/feel at the water pump just behind its pulley, it is common for water pump glands to fail and only leak whilst running or hot and stopped, the leak will dry up as soon as it gets out and you cant see any water for trying to. most water pumps have a drain hole somwhere on the bearing housing feel for damp around it.

If its lost the impeller you will get rapid over heating.

On some models the plastic thermostat housing can leak when hot.