cab heater issue
Thread Starter
|
Freshman User
Joined: Nov 2007
Posts: 26
Likes: 0
cab heater issue
I have an issue with my heater and was wondering if anyone else can give some advice or sugesstions. 2003-F250-6.0L 4 x 4 Crew cab King Ranch. When I let my truck idle the temp gauge shows the engine warms up just fine. The heater still blows cool air until i actually drive the truck then the air warms up just fine. If the truck sits at idle in the driveway for an extended period the air never gets warm. I am thinking possibly the water pump failing or a heater core failing, or maybe the serpentine belt is wearing out? it almost seems that until the warm water is pushed thru the core it does not get warm. Is it possible the heater core could get plugged up with something? If anyone has some things for me to check or consider please let me know. So far this forum has been very helpful! The mix of the actual techs and experienced diesel owners is really helpful. This is my first diesel truck, so everything seems to be a learning curve. Thanks Rick...
Posting Guru
Joined: Jul 2005
Posts: 1,617
Likes: 4
From: Denver, Co
That is a good one...
I would put a vote on the blend door not closing. Either there isn't quite enough boost at idle to get it to close, or the door itself is getting stuck & the normal bumps while driving help "coax" it to close.
If the water pump was going/gone, you should have overheating or high temp issues.
If the heater core was going/gone/plugged, you should have no heat.
If it were the thermostat, you would have overheating issues. (Unless of course, it were one of the fail-safe thermostats.)
I would put a vote on the blend door not closing. Either there isn't quite enough boost at idle to get it to close, or the door itself is getting stuck & the normal bumps while driving help "coax" it to close.
If the water pump was going/gone, you should have overheating or high temp issues.
If the heater core was going/gone/plugged, you should have no heat.
If it were the thermostat, you would have overheating issues. (Unless of course, it were one of the fail-safe thermostats.)
Moderator
Joined: Aug 2005
Posts: 164,377
Likes: 82
From: MA
Originally Posted by rcsjr4546
I have an issue with my heater and was wondering if anyone else can give some advice or sugesstions. 2003-F250-6.0L 4 x 4 Crew cab King Ranch. When I let my truck idle the temp gauge shows the engine warms up just fine. The heater still blows cool air until i actually drive the truck then the air warms up just fine. If the truck sits at idle in the driveway for an extended period the air never gets warm. I am thinking possibly the water pump failing or a heater core failing, or maybe the serpentine belt is wearing out? it almost seems that until the warm water is pushed thru the core it does not get warm. Is it possible the heater core could get plugged up with something? If anyone has some things for me to check or consider please let me know. So far this forum has been very helpful! The mix of the actual techs and experienced diesel owners is really helpful. This is my first diesel truck, so everything seems to be a learning curve. Thanks Rick...
If so then maybe they didn't activate the accessory circuit for the heat to start..
just a guess
Super Moderator
Joined: Jul 2004
Posts: 21,113
Likes: 3,939
From: Ohio
My 03 does the same, hot air running, warm air at idle. I am going to try a new front cover from and 04 that has the bigger water pump which should increase circulation. This would be a direct fit and since I want to install a new low pressure oil pump, plus a fluid damper... 3 issues at once. The better coolant flow should address head temperatures when running custom tuning.
Thread Starter
|
Freshman User
Joined: Nov 2007
Posts: 26
Likes: 0
sounds like to me it is a common thing with this engine and not something i should be concernced with? Coolant level is fine (first thing i thought too). Maybe i will take into the dealer for a look. I know it seems common, but i would not think it should do that as a normal thing.
Trending Topics
Postmaster
Joined: Dec 2003
Posts: 4,196
Likes: 10
From: Arizona
rcsjr4546,
Unlike a gas motor a diesel engine actually cools off when it idles. Diesel engines do not produce much heat a low idle. The high idle mod will help keep the engine up to temp when it is idling for extended periods. It is not good practice to let a modern diesel engine with and EGR system idle for long periods of time. It can lead to wet stacking, EGR coking etc. You are better off to start the truck and drive off after 30 seconds - 1min. FYI the factory temp gauges are just glorified idiot lights.
Unlike a gas motor a diesel engine actually cools off when it idles. Diesel engines do not produce much heat a low idle. The high idle mod will help keep the engine up to temp when it is idling for extended periods. It is not good practice to let a modern diesel engine with and EGR system idle for long periods of time. It can lead to wet stacking, EGR coking etc. You are better off to start the truck and drive off after 30 seconds - 1min. FYI the factory temp gauges are just glorified idiot lights.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread Starter
|
Freshman User
Joined: Nov 2007
Posts: 26
Likes: 0
Thanks for your feedback it helps reduce my concerns....your are correct, i am used to gas engines and this diesel thing is a totally different animal. Thanks again i am sure i will be back with more concerns/questions. Rick
Hold an 03 water pump up to an 04 and you will see what I am talking about. Just my 2 cents worth 