W210 - Coolant Level Conundrum

[ShinyF1]

I have a MY2000 E320 CDI, which is probably well into its retirement years.

The 'Coolant Check Level' warning came up the other day, initially intermittently and now every time it starts.

There is no obvious leakage, and the operating temperature rises steadily [but quicker than before?] to approx 95°C [see pics attached], but the level in the reservoir does appear to be falling.

It has not overheated as yet, and there is no sign that the fans are kicking into overdrive.

Could it be a faulty sender or is it more likely there is a leak or a blockage somewhere.

Suggestions appreciated, then no doubt will call Olly to book it in anyway...

Thanks

Sean

 

[Iceviolet]

Is the undertray wet at all? It is sometimes hard to tell if there is a leak due to rainwater etc getting on the tray too.
My coolant level kept dropping and it turned out to be a very small leak from the water pump. Leaking out of the pump itself up the shaft and into the engine bay on to the undertray.
New pump and 30 minutes to fit, easy job. This was on a w210 220cdi though so may be slightly different on yours.

 

[ShinyF1]

Undertray has departed a while ago, and never replaced it. Only the front apron part still there.

 

[W210Virgin]

I'm led to believe that the 3.2 I6 engine is not a head gasket muncher and your engine temp is exactly where mine sits. I'd go with what Iceviolet says above and investigate the water pump first. Space is very tight at the front of the 3.2 as there's 50% more engine in the way and you certainly won't do that job in 30 mins!

 

[sallison1504]

Is that showing minus 4.5degrees Celsius?

 

[Iceviolet]

Is that showing minus 4.5degrees Celsius?

Looks like it! Probably a faulty sensor. Also the gear indicator and clock is all pixilated.

Fixing this was my first job when I got my w210, It really did annoy me!! £15 for the non-bonded graphite ribbons off ebay and easy to install, with a little patience. Had to take the clocks apart twice though as the first time I did not clean the contacts well enough. The contacts on the clocks needed cleaning with a solvent (nail varnish remover) and then lightly sanding with some fine emery paper to bring back to a shiny clean surface then wiped clean again with solvent.
Such a satisfying fix!

 

[louwdj]

The contacts on the clocks needed cleaning with a solvent (nail varnish remover) and then lightly sanding with some fine emery paper to bring back to a shiny clean surface then wiped clean again with solvent.

Why not Electrical Switch Cleaner in an aerosol can? Longer lasting.

 

[sallison1504]

Apparently those matrix displays have a tendency to lose a few bits here and there. If the car thinks it's only -4.5, correct me if I'm wrong, but is this the same as the temperatures the ECU and TCU are using to set the car up. If the car thinks it's that cold it will rev a lot until it's warm :/

 

[ShinyF1]

Is that showing minus 4.5degrees Celsius?

Standard pixellation problem on secondary displays... It was 14.5°C

 

[BlackC55]

Water pump leaking?

 

[Iceviolet]

The contacts on the clocks needed cleaning with a solvent (nail varnish remover) and then lightly sanding with some fine emery paper to bring back to a shiny clean surface then wiped clean again with solvent.

Why not Electrical Switch Cleaner in an aerosol can? Longer lasting.

Didnt have any

 

[ShinyF1]

Water pump leaking?

I think that might be it. Still not overheating. I'll get in touch to book in

 

[BlackC55]

I think that might be it. Still not overheating. I'll get in touch to book in

Ok.

 

[ShinyF1]

And now heating not working - could there be a connection?

 

[W210Virgin]

If you've lost heating you might have air in the heater matrix if your level has dropped a few times. You'll get no circulation through the heater if it is air-locked.

 

[GH421]

My friend has a w210 E300 TD and he was getting random coolant lights every now and then.

After a few months it over heated needing a new thermostat.