deathrider666

Just bought a 2002 Mondeo TDCI but when driving the car back the heaters didn't get warm at all, after about 15 miles I stopped for fuel then when I got back in the car and started it up, the heaters were working great as they should.

After a few more miles the heaters seemed to go cold again and never warmed back up.

Fans are working fine but not the heater, anyone have any ideas?

fordnut

Hi.
what is the engine temp gauge saying when the heater is blowing hot/cold?

A problem I had with my TDCI mondeo with very similar symptoms turned out to be the oil thermostat which is located on the back of the waterpump.
My temp gauge would stay really low when driving and would raise for a while if i stopped for a while with the engine idling. My heater followed whatever the gauge was saying.
I tried changing the main engine coolant thermostat first as it is the easiest to do.
This didn't fix my problem, so I then changed the oil cooler thermostat which did.


Hope this helps,

Nick

mark_24v_wiring

iTrader: (1)

As above its a pain in the arse to change glad i did mine as the water pipe from it had to be replaced too

RS500/364

http://www.fordwiki.co.uk/index.php?...Changing_(TDCi)

deathrider666

I've driven the car today to take note of what the temp gauge is doing.

Did a few little journeys with the heaters only kicking in the 4th journey (kicking in as soon as the car started).

The temp gauge looks to be staying in the middle when up to temperature regardless of whether the heaters are working or not.

Does this mean it's the oil or water thermostat?

RS500/364

did u read the link !

deathrider666

Yes it's a very good link but judging by what fordnut said about his temp gauge, does this mean it's the water one and not the oil one?

deathrider666

Does anyone agree with this way of thinking?

The temp gauge in the car is the temp of your water/coolant, if there was a problem with the water thermostat the car would overheat, however as the temp gauge in my car seems normal there can't be anything wrong with the water thermostat.

Therefor I am going to change the oil one as I think logically it makes sense.

RS500/364

its the oil temp thermostat

fordnut

The cause of your problem is most likely the oil heat exchanger thermostat. It has engine coolant running through it tho, as its job is to keep the engine oil/ engine coolant temp regulated relative to each other.

jasblain

http://www.fordwiki.co.uk/index.php?...Changing_(TDCi) This link does not work. Could someone please let me know where the sensor is and where I can find a new one at a decent price.

Thanks in advance.