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Discussion Starter #1
I have a 1.9 non turbo t4 and the only way i can think of to warm the inside now is to have one of them fire pits in the front!!!.
When you switch the blower on its warm for a few seconds then gets cooler. Its had (deep breath):
new waterpump,
thermostat,
2 changes of coolant,
the matrix bled and flushed through
,the heater control valve has been off and checked and seems to work fine,
heater cables work.
pollen filter
all heat ducts are connected.
seems to be anice steady flow of coolant in and out of matrix.
the only fault i have found is the aux water pump on the bottom left of the rad is not working but from what i have read on here it only comes on once the engine is off any way to aid cooling???.
The top dash vents seem to be the warmest but even they are no warmer than blowing on the screen yourself. is there some kind of fresh air flap that may not be closing on the heater box????.:* any ideas?? its really getting to me now and me and the van are going to have a major falling out soon!!!
 

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Discussion Starter #3
afraid not i am thinking about having the blower unit out from behind the dash at the weekend to see if its a problem that end. if i find anything i ll let you know.:confused:
 

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I have experienced a similar problem with my T4. I changed the water pump and the water pump housing and it cured the problem.

When you replaced the water pump did you change the water pump housing? This can wear just as much as the water pump impeller due to being a softer metal than the impeller its self.

I know that the T4 needs good water pressure to pump the water around the heater matrix as the inlet and outlet is higher than the coolant level in the expansion tank so the coolant will not naturally flow around the heater matrix.

Another problem could be a week expansion tank cap as these are designed to release excessive pressure build up in the cooling system.
 

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Discussion Starter #6
Well i went for it this morning .I think the problem is the flap that is located behind the pollen filter.It is stuck fully open so is constantly sucking in cold air so the matrix never gets a chance to warm up proprly.

This is the left hand part of the heater box that is located behind the glove box. its easy to remove the lower dash then you just remove the fan and sensor and unclip it from the main heater box.There is also a pipe going to the top of the vacuum mechanism and a cable to unclip Once you have done this its under the bonnet and remove the pollen filter cover/filter.You will see a backing plate with 3 allen key bolts,undo these and you should be able to remove the heater box section we want.

Once removed you will be able to see the flap through the fan hole.You will also see the mechanism on the left end of the box. From what i can make out when you push the recirc air button this flap should shut so the fan draws air from the cab rather than horrible cold air through the pollen filter. I belive the diaphram inside my vacuum unit is fu-bar'd as its sucking but not moving and you can hear air beng drawn in from around the arm thats meant to move the mechanism(if that makes sense):eek:

This is my quick fix to ensure the flap stays shut and so far it seems to have worked:ILU:. Re-assambly is as described but in reverse just becarful when putting the metal clips back on the heater boxs. Hope this helps a bit and saves a few of you ripping out the heater matrix.T:
 

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Discussion Starter #7
the previous post did have pics but they seem to have vanished i ll see if i can get them back.
 
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