How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Matt Your Own Question

Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 20389
Experience:  BEng hons Mech engineering, in auto industry 22 years
Type Your Car Question Here...
Matt is online now

The heater on my 2.9 diesel Sedona has stopped working. Ive

Customer Question

The heater on my 2.9 diesel Sedona has stopped working. I've checked my coolant level thinking I might have a leak but it remains at the same level. My next thought was the thermostat which I have taken out but its made no difference. I can only travel around 5 to 10 miles before the temp gauge starts to climb above its normal running position
Submitted: 2 years ago.
Category: Car
Expert:  Matt replied 2 years ago.

I'd start by fitting a new thermostat as its needed to control the flow around the engine and it sounds like the cooling system may not be in good shape if its overheating and yet you have no heat?

Whilst the thermostat is being replaced you might as well also reverse flush the cooling circuit (remove top hose to rad and use a hosepipe to push water into the engine until you get clear water out of the radiator hose) and top up with 30-50% fresh antifreeze. Also check that the small diameter bleed hoses that run from the top of the radiator and the top of the engine aren't blocked as this allow the air to vent back to the header tank automatically.

then have a feel of the two coolant pipes that pass into the car through the engine bay bulkhead, both should be warm with a warm engine. If they're not then its likely the heater matrix is blocked and you should do a reverse flush on the cooling system to try and clean it out. This is done by removing the top hose from the radiator and placing a garden hose into the engine water outlet, and then run the hose until you get clean water coming out of the radiator.

If this doesn't help this only leaves checking out the motor / cable that move the air mixing flap that allows the hot air from the matrix to enter the car air system.

This flap is controlled by the temperature knob / dial etc and I think is controlled with a small motor for your car so the thing to do is first get access to the back of the control knob and measure the voltages is present there, then trace the wiring back into the dash from the control to locate the motor.

It’s worth first checking the fuses for the fan / control circuit

I'd recommend first removing the glovebox ( undo lower edge hinges from dash) to gain access to the dashboard inner and also allow you to shine a torch to the back of the central console so you can start tracing the wire back and see how things are put together

What Customers are Saying:

  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex

Meet The Experts:

  • Greg



    Satisfied Customers:

    Automotive diagnostic tech
< Last | Next >
  • Greg's Avatar



    Satisfied Customers:

    Automotive diagnostic tech
  • Matt's Avatar


    Mechanical Engineer

    Satisfied Customers:

    BEng hons Mech engineering, in auto industry 22 years
  • Ross's Avatar


    Diagnostic and repair technician

    Satisfied Customers:

    Licensed diagnostic and repair technician
  • Rob's Avatar


    ASE Certified Technician

    Satisfied Customers:

    30 years trade experience
  • uk_iaibal's Avatar


    UK Car Mechanic

    Satisfied Customers:

    Verified Car Mechanic.
  • Billy's Avatar


    Trainer/ Master Technician

    Satisfied Customers:

    Trainer 8+ years, master tech. 10+ years, SAE member
  • Mike Kelly's Avatar

    Mike Kelly

    Auto Service Technician

    Satisfied Customers:

    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.