Hi folles have recently purchased a mk5 Mondeo 1600 Tdci couple of thing car drives great but couple of thing’s number 1 heater is not getting warm 

2 black soot in expansion tank

it is due for a cambelt change so was going to replace belt water pump etc and thermostat and give it a good flush out as someone said to me water pumps are prone for the impeller breaking off and prone for thermostats playing up I’m 99% it hasn’t got gasket or head problems just wondered if anyone has come across this any help would be appreciated 

First I've heard of the 1.6 TDCI impellor being a common fault...and I've owned a few of them.

First thing I'd do in this case is have the coolant sniff tested for exhaust gasses.  If there's exhaust in there, you're either looking at headgasket or EGR cooler.

Hi thanks for info I’m pretty sure it ain’t head gasket well fingers crossed where is the egr cooler situated what’s that big aluminium block on the front with water pipes leading to it. Funny enough a mechanic send about the impeller on the pump could cause a lot of problems it’s ironic I let it run idle for 20 minutes no rise in gauge but take it for a run gauge does go up when driven hard so could be the pump going to change that and thermostat as well when I do the belt what do you think 

Big aluminium block?  Are you sure it's not a 1.5 TDCI like this?

No it’s a 1600 Tdci 2015 mk5

1 hour ago, Richard boraston said:

No it’s a 1600 Tdci 2015 mk5

I'm not sure what you mean then.  There isn't an ally block on the 1.6 TDCI.  The turbo is on the front but it's not water-cooled.

 

Edit - Unless you mean the oil cooler below the filter housing?

The EGR cooler is at the back of the engine.  Looks like this:

Thanks for the info very helpful