Mk3 mondeo 1.8 petrol 51 plate, the heater takes yonks to even get warm yet BOTH heater pipes are hot and the blower inside the car works ok, fitted a new thermostat (old one was shoot), no air locks, and it's still the same, what am I missing? sure I've read on here somewhere that the mondeos have two thermostats.

I think i read some where , there are two , one for the water and one for the Oil

thanks Pree for your reply, I wouldnt have thought the oil system having a thermostat,jez imagine that packing up thats your engine caput, anyway I've tryed a new expansion bottle cap and it's still the same, cold yet the heater pipes are hot, whats the chances of it being the water pump being partly broken inside (the cars not overheating though)

my diesel mondeo has an oil cooler, unfortunately its located low in the system so you will need to drain a good amount of coolant to change i would imagine

I had a VW Golf with the same problem that you have. It turned out the matrix was pretty blocked. First I tried back flushing the matrix with a hose, that improved the heater a bit. In the end it started to leak, so I changed the matrix and that solved the problem. The heater matrix was less than 30 quid BUT it took the best part of a day to change it because the dash and heater box had to come out.

You could try a cooling system flush additive as well, I've used the one that comes in two bottles, with quite good results. Click here

Does anybody know where the HCV (heater control valve) is on the mondeo?

Fishpond

I found this it maybe related.

"I have had the same problem on three Mondeos. People will rightly tell you to check the coolant levels, heater matrix etc but the problem I have had on all three occasions was the cable from the temperature switch not opening the valve properly. If you look on the side of the heater unit to the left of the clutch pedal you will two small cogs with a cable attached to the top one. Use a screwdriver to fully turn the cogs and it will open up the valve and with a bit of luck you should get hot air."

it also reports that some cars have eletric version which is near the wipers that does the same but some times fails not allowing the water through to heat the car