Question about 2000 Mercury Grand Marquis

1 Answer

No heat in my 98 Grand Marquis

I have flushed the system and replaced the thermostat (twice to be sure) and blew water through the heater core. I still have no heat. I am wondering if the temperature control unit is not sending the signal to direct the airflow through the heater core. Does anyone have any ideas?

Posted by on

  • slackkeymike Jan 22, 2009

    I will add that the first time I replaced the thermostat, 2 yrs ago, it started working again! Then some time later it stopped. That made me think trash in the heater core. I did replace the thermostat once again, but no improvement. You asked for a clarification, but I am not sure what you are looking for. Is there a way I can test the TCU and HCV? Surely there is someplace where the mechanism reroutes the air through the heater core. Diagrams anyplace?



    Mike

  • Richard Delahant May 11, 2010

    It could be the temperature control unit, without checking it it;s only a guess. Could also be the heater control valve.

×

1 Answer

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

Are you shure that you dont have trapped air in the heater core? get a big funnel that will fit tightly in the radiator filler and fill with coolant and run the car to normal operating temp and watch for the level to drop or bubbles to evacuate into the funnel. on really stubborn air locks i have had to squeeze the hoses to pump water through the heater core.





































































Posted on Feb 11, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

How to back flush heater core 2007 grand prix


drain coolant system locate heater cores hoses going through firewall you need to buy the radiator flush kit at any auto parts stores. remove heater cores hoses from one end or buy extra long heater hoses same size as heater core hoses in vechicle at auto parts store use the flush kit when you flush through one of the heater core hoses let the other hose drain in a drain pan when you use home garden hose use low water pressure dont use garden hose to the max or you will rupture heater core. your best bet let radiator shop flush whole coolant system. because heater cores hoses are in a tight spot.make sure engine off if you just going to flush out heater core only .after flushing heater core good time to replace heater core hoses.if job too hard or complicated let radiator shop flush out radiator the engine block and heater core because if radiator stopped up or engine block stopped up the gunk and rust will reenter plug up heater core.if you tight on money you can flush out your own radiator.drain out radiator using large drain pan. remove top radiator hose and remove bottom radiator hoses connect to water pump.use garden hose with flush kit part with water pressure not too high put garden hose to top radiator hose run water until clear water run out bottom radiator hose in drain pan,the flush out engine block remove thermostat.if you had another spare thermostat housing with RTV SILICONE SEALANT THAT HAS SET UP INSTALL THERMOSTAT HOUSING BACK TO ENGINE WITHOUT THERMOSTAT FLUSH OUT THE ENGINE BLOCK, WHEN DONE INSTALL NEW THERMOSTAT THEN INSTALL ORIGINAL THERMOSTAT HOUSING WITH NEW ORING WHICH YOU BUY AT DEALERSHIP.IF ALL SOUND COMPLICATED LET RADIATOR SHOP FLUSH OUT COOLANT SYSTEM.

Nov 27, 2012 | 2003 Pontiac Grand Prix

1 Answer

My 1984 grand marquis does not get heat


did everything said to do put new heater core in and a new thermostat instill no heat

Oct 08, 2012 | 1984 Mercury Grand Marquis

2 Answers

Cannot get the heater to work


CHECK SEE IF HEATER BLOWER MOTOR WORKING, REMOVE HEATER BLOWER MOTOR HOT WIRE HEATER BLOWER MOTOR SEE IF BLOWER MOTOR WORKING BLOWER MOTOR FAULTY OR YOU HAVE FAULTY WIRING AT BLOWER MOTOR AND RESISTOR.

Nov 05, 2011 | 1996 Mercury Grand Marquis

1 Answer

I do not have any heat in my 1996 grand marquis


could be heater control or plugged heater core.. heater core could be cleaned out by unhooking heater hoses and running water through or a radiator flush.. if its your valve youll need to replace..

Feb 06, 2011 | 1996 Mercury Grand Marquis

1 Answer

Have a 99 nissan altima that wont heat at an iddle. have changed the 2 thermostats and water pump. also bleed the system pre the tech service bulitin, and still have no heat at times at an iddle. any...


yes,have suggestion.leaking coolant into the passeger side floorboard? film on the windsheild at anytime? suggest a bad heater core. or this,heater core stopped up.needs to be flushed.flush radiator with a common flush found at autozone,advance autoparts stores.or any other auto parts stores. remove your heater core hoses on the firewall[2 small hoses that go from the motor through the firewall to the heater core itself] flush the heater core there manually.push your water hose to the passenger side there and turn hose 'on' and watch the flow out the other side.[both hoses on the firewall will have to be off[or disconnected]to do this properly. your problems here,and since you've replaced the thermostats twice,suggest that this is your issue. thank you for choosing fixya.com

Jan 28, 2011 | 2005 Nissan Altima

3 Answers

No heat , replaced radiator , water pump, rad. cap , hoses and flushed system twice.blows cool air.whats left?


Thermostat.? if you haven't? Do it first then try it. While the car is running for a while touch the heater hoses that lead to the firewall. if one is cold and one is hot? You have a blocked Heater core. Follow the hoses back to the engine. Unconnect them both. By using a garden hose flush out the heater core do one side and then reverse by doing the other hose Lots of junk will come out so be care ful. Mistake people make is "Flushing the system" That doesn't mean your flushing the heater core.
Seeing that you have done everything else it could be the thermostat which you didn't list or the heater core being clogged. When you finished installing the thermostat and flushing the heater core out. Replenish the coolant system . If you have a bleeder on the thermostat housing? use it . loosen it and top off the fluid until you see fluid comeout of the bleeder. The system being air bound would cause no heat..

Jan 10, 2011 | 2000 Buick LeSabre

Not finding what you are looking for?
2000 Mercury Grand Marquis Logo

374 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mercury Experts

yadayada
yadayada

Level 3 Expert

60960 Answers

Fordexpert

Level 3 Expert

5331 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Are you a Mercury Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...