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Heater v8 auto

Discussion in 'V8 Engine' started by mike rigg, Sep 24, 2017.

  1. mike rigg

    mike rigg Member

    hi
    As the colder weather is on its way I thought I'd try the heater today on my run. Having bought the car a couple of months ago I've never tried it until now.
    Unfortunately little or no heat emerged from it. The return heater pipe is Luke warm so I assume the hot water isn't going through it. The car was restored a year or so ago so I'm assuming all is well with the matrix. Can an air lock be the problem or does the heater valve need checking /adjusting. Ideas on help solve this would be appreciated, however I don't want to strip down the car.
    Thanks
     
  2. harveyp6

    harveyp6 Well-Known Member

    There isn't a heater valve, the heat is controlled by flaps with the coolant running through the matrix all of the time, so you can make sure that the flaps are working as they should, and also make sure that the heater hoses are fitted to the matrix correctly, the top hose outlet on the engine feeds into the bottom of the matrix. You can also check the thermostat, and if it has an 82 summer stat fitted, you can change that for an 88 degree one. After that if it still doesn't work efficiently then the matrix needs to come out and either be professionally rodded through, or replaced with an exchange unit.

    I'd be surprised if the matrix was replaced as a matter of course during a restoration.
     
  3. rockdemon

    rockdemon Administrator Staff Member

    Well worth doing. 50 years of crud and a good p6 heater is toasty!
     
  4. mike rigg

    mike rigg Member

    Thanks Harvey will check the hoses tomorrow, but certainly the hose coming out of the top of the matrix was Luke warm. Is getting the matrix straightford.?
     
  5. rockdemon

    rockdemon Administrator Staff Member

    search for demisterman on google and ebay
     
  6. mike rigg

    mike rigg Member

    Hi
    Checked the hoses and they are connected correctly. So next job is to see if there is an air lock, i.e. By slacking off the top outlet hose. If that doesn't work will try flushing the matrix through during the winter garage months. If that doesn't work well so be it as I can't see me taking the matrix out. Surprised there is no heater valve as the workshop manual refers to a valve but bow to knowledge out there.
    Thanks
    Mike
     
  7. clive P62

    clive P62 Active Member

    Hi
    The only model p6 to have a water valve is the factory air con v8 cars.
    Clive.
     
  8. vaultsman

    vaultsman Well-Known Member

    As Harvey says the heat is controlled by flaps, which are faced with foam to ensure efficient sealing within the box.

    That foam will almost certainly have disintegrated by now, and the box needs to be dismantled to be replaced.

    Alternatively, you could talk to Alexandra who can supply you an exchange unit fully refurbished. Contact her via the link on this recent thread:

    Heater box anyone??

    Failing that, wrap up well! ;)

    Good luck, Stan
     
  9. mike rigg

    mike rigg Member

    Hi
    Finally getting round to trying to sort out heater. There obviously is a flow and return to the heater. Am I correct in assuming the top heater connection is the flow and if that's correct which connection on the engine does it go into.
     
  10. harveyp6

    harveyp6 Well-Known Member

    The top hose connector on the engine goes to the bottom hose connector on the heater.
     
  11. mike rigg

    mike rigg Member

    Thanks Harvey, hoses are correctly fitted. Have taken out the thermostat and it was fitted with the air hole downward. Got a new thermostat so will see how that goes. Thanks again.
    Mike
     

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