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Heater again!

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Hi All,its that time of year when heater operation becomes important, as usual I ignore it through the summer promising myself I will fix it in the winter!So here we go again,the heater matrix gets warm and the hot/cold control works,all vacuum hoses are in place under the dash,the screen /interior control moves the control valve and the fan works.All I get is luke warm air onto the screen and cold feet! Any ideas anyone?Is there a vacuum hose attached to the engine somewhere?Mine is an 84Turbo without the heater mod.The other half is starting to getting peed off about having blankets round her feet.

Cheers Paul.(just extracted myself from the footwell!)

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Air lock?? Low water level, blocked matrix??

Think yourself lucky, when I turned my blower on backing down the hill into the garage waqter piled out from behind the dash. Stops when you turn the fan off so I'm guessing the fan housing filled up then it was parked on the drive at a funny angle!! :)

Another quick fix is extra socks and a good pair of gloves!!

Chunky Lover

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Jack up the front of the car and pull off the two heater hoses then use a garden hose to force high pressure water thru the heater matrix to flush it out.

Make sure you are getting a good vacuum by pulling the line to the flapper control valve while the engine is running you should have a good vacuum on that line.

Afraid you will have to contort yourself back under the dash again :unsure:


'83 Turbo

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Air lock?? Low water level, blocked matrix??


I am surprised the heater core doesnt have an air bleed, considering it sits pretty high in cooling system.. airlock maybe a possibility.

Paul: I would also check to make sure the luke warm air isnt caused by the front fresh/ recirc door allowing too much cold outside air into the mix. There is a vacuum dashpot on the air source options door under the cover in the boot area (where the fans live as well). If that door is open to the louvers at the base of the windshield, outside air will pass thru the heater core.. to boot if the dashpot on the rhs side of the heater box fails, depending on how it was set up, it will allow additional unheated air directly into the cabin thru the center dash vents. That dashpot controls the ac max door.

So if the dash vents are all running at full flow, I dont imagine the heater core would see much airflow since most of it (cold air) would get vented to the cabin before it gets thru the heater core.

Close all the dash vents, make sure the air source is recirc and bleed the air out of a clean and flushed heater core and hoses as Louis suggested.

my 0.02, hope that helps..J

Edited by f1karting

If you set no goals you shall surely reach them..

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My 87 has a bleed valve under the front bonnet. Near the drivers front wheel. It took me quite a few times to get the air out but the heater works pretty good now.

Top off the coolant, start the car and let it get warm. Take the car for a 15 minute ride. Park the car (leave it running). Open the valve slowly, let it spray a little coolant, close it down.

Next day repeat proceedure.

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Said this before on here, but I jack the rear of the car right up, fill the cooling system and run the engine with thecap off till the thermostat opens (then replacing the cap).

This technique works for me in purging the heater matrix(and rad) of any trapped air. :P

Try it and see. :P

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Hi all,thanks for all the ideas,I will start with the easiest and work my way up to the ones requiring yoga exercises!!Just changed the thermostat only to find the new one leaked and then that my low temperature reading is due to a faulty sender or voltage stabilizer, anyone know of a sure fire test to work out which!?By the way has anyone been brave enough to get the old sender out without buggering the ally pipe!!!?(have you seen the price of a new pipe?!!!Must be gold plated inside.)Roll on summer.

Cheers Paul 84T(with slight hypothermia!)

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