Mondeo mk5 heater issues please help

[Onlyme]

I've picked up a 2015 2.0 tdci and I have no heating .

whatever temperature I set it at it still only blows cool air. I've checked the two pipes going to the bulkhead and one of them feels warm/hot but I just can't get any heat coming through the vents. When driving the temp needle stays in the middle and no signs of overheating.

 

can anybody tell me what could be the possible problem please.

ive checked the coolant levels and let the cap off the headed tank with heating on and engine running incase of an airlock but still no luck.

 

what would you guys suggest ?

[MasterTechTip]

I can only imagine this being 1 of 2 things that I've come across on Mk5 Mondeo.

1. The coolant pump impellers are quite prone to snapping off the shafts. This stops coolant flowing around the engine which in turn means you aren't getting any heat to the heater matrix. Fairly easy to test this, get the vehicle hot and see if coolant is returning to the bottle from the top small coolant hose. If no coolant is returning then that's your issue. 

2. The temperature blend door motor is faulty and not adjusting the hot/cold air mix coming out of the vents meaning you're only getting cold. Bit harder to check this and may require some trim removal to view the motors 

[Onlyme]

Thanks for the reply. I've had the waterpump replaced the day before I bought the car along with the timing belt. The heating issue was picked up on a service report back in December 2019.

how would the temperature blend door motor be diagnosed as faulty ?

[MasterTechTip]

It wouldn't be moving or getting jammed. Like I said it won't be the easiest to see and you need to know what you're looking as there will a few motors moving flaps 

[iantt]

Or could it be the in vehicle temp and humitiy sensor faulty thinking it's hotter than it is? 

[Onlyme]

I'm not sure exactly. The mechanic I took it to said that he thinks it's the heater core ( I think that's what he said ) on the side of the engine .

is that where the temp sensor is located ?

[MasterTechTip]

20 hours ago, iantt said:

Or could it be the in vehicle temp and humitiy sensor faulty thinking it's hotter than it is? 

That's not a bad idea, not known one of those to fault on a Mk5, ideally need to put data logger on it to view the temp it's reading. 

[MasterTechTip]

20 hours ago, Onlyme said:

I'm not sure exactly. The mechanic I took it to said that he thinks it's the heater core ( I think that's what he said ) on the side of the engine .

is that where the temp sensor is located ?

The heater core (heater matrix) sits at the bottom of the dash at the very back. You can't physically view it without taking the dash out and if it was faulty you'd have coolant leaking into your foot wells. 

The ambient temp sensor is located above the drivers left knee behind a bit of trim, sort of underneath the push to start button

[FatHead1979]

On 9/24/2020 at 5:56 PM, MasterTechTip said:

The heater core (heater matrix) sits at the bottom of the dash at the very back. You can't physically view it without taking the dash out and if it was faulty you'd have coolant leaking into your foot wells. 

The ambient temp sensor is located above the drivers left knee behind a bit of trim, sort of underneath the push to start button

Isn't that the sensor that has a little fan to ensure that air always flows over the sensor?

[MasterTechTip]

14 hours ago, 1979Damian said:

Isn't that the sensor that has a little fan to ensure that air always flows over the sensor?

Yeah that's the one, sometimes you can hear them buzz behind the dash 

[raz56]

Sorry to wake up the old thread, did you manage to figure out what was the problem?

I am having same issue, very low heating, cold on passenger side and warm on driver side. I have changed the thermostat, flushed the radiator and cooling system, chnaged the motor flap actuator, did forscan test, but can not find an issue. Can anyone suggest which direction I should follow?