6.0L Power Stroke Engine and DrivetrainDiscussion of the 6.0L Power Stroke diesel engine and drivetrain in the 2003-Up Super Duties and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 6.0L Power Stroke engine.
All right here are my issues, the heat will not work at low rpm's and it will only start blowing hot when the engine rpms are over 2,000. I have checked the coolant and that is fine. a few months ago I had to add over a gallon of coolant, I took it to the dealer and they said that everything checks out, 0ne day later it started billowing white smoke I took it back in and they replaced a egr hose and I have'nt had a problem since. Thermostat? head gaskets? please help
what does the temp gauge read,Possible thermostat issue or could even be a waterpump going out.But ususally you will get a overheat issue if its pump related.The clutch fan is Not stuck on is it?
If you truly have luke warm air blowing from your vents, and all fluids are at the correct range when the engine is cold and sat overnight.I would say the thermostat is stuck open meaning the engine block cant heat enough water/coolant to supply heat when the system is basically wide open
and full flowing. The thermostat is designed to not let full flow until an desired temp @195 give or take.
My wife just called me and reported the same problem. All gauges normal but no heat. Temp today was at -7. Anyone with any ideas?
Have the heater core flushed out at any radiator shop. Probably plugged up. You can check by feeling the heater hoses. Both should feel fairly warm at operating temperature. If one is noticeably cooler than the other that is your problem.
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2006 F350 - Amarillo Package,loaded with all the toys, 4" MBRP cat back exhaust, Autometer EGT gauge, Viper 791XV auto start/cool down timer/alarm, Pioneer AVIC-D3 navigation/XM Radio/Sirius, 2.5" Tuff Country Leveling kit, KC Hilights front & rear, Dieselsite.com coolant filter, SkyJacker dual steering stabilizer, Firestone Ride Rite airbags w/onboard compressor, Kleinn Train Horns, Bilsteins all the way around, Recon LED's in the back, Programmed with the SuperChips 1805 Tuner always set on Tow Safe for a little extra get up and go.
30' Cardinal 30TS 5th wheel. The weekend home away from home.
"The early bird may get the worm, but the second mouse gets the cheese."
I believe these trucks have a valve that does not allow the coolant to flow to the heater core in the air conditioning mode. It is controlled by the little vacuum pump. I would check to see if your 4wd works as the hubs are controlled by the vacuum pump. I am not sure why it wouldn't work below a certain rpm but it could be that the little vacuum pump is going bad or has some leaks or a bad electrical connection.
__________________ 2003 F250 XLT 4x4 Sport Crew Cab,
Built May '03, Bright Red, 6.0 Auto, ESOF 4x4, 3.73LS, 4.5" Edge Lift, 315/75-16 BFG KO A/T's, Polished/Clear Powder Coated Diff Covers, Weld Cheyenne 8 Wheels, Line X, Overhead DVD, Torza Tonneau Cover, 30' Fleetwood Gearbox Travel Trailer
yes trace the heater hoses from engine and see where the hot hose get cold and BINGO
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Jim Sult / Excavator (we dig it) Trying to fix it? KISS IT"KEEP IT SIMPLE STUPID" Avatar- purchased off Ford lot as NON RUNNING ENGINE - I drove it off lot in 1 hour/ my everyday 1996 F250 XLT Ext Cab, Powerstroke, 4x4 Dana 60 , Bilsteins shocks, BTS Trans, BabySwamps,Tony Wildman Chip, AutoMeter Pyro/Trans/Boost, Tymar intake, MBRP 4 in turbo back exhaust, 209000 miles,D&B HT Starter
1996 F350 XL PowerStroke 4X4 DRW, Auto Trans, Stock Work Dump truck, DDP down pipe,Tymar intake, 113000 miles
1997 F350 XL 2x4 DRW Powerstroke , DP Tuner PCM, 5 speed,Luk Clutch Tymar intake. DPP downpipe, 185,000 miles
I too had that exact same problem with my 03 6.0l. When the engine temp. was normal and the truck was brought down to an idle, it was just like the a/c was turned on. Only noticed this problem during the cooler weather.
Truck was constantly using a small amount of antifreeze and would never stay at the "new" fullmark. Also appeared that the engine temperature would reach "normal operating" range a little faster than normal.
I bought a digital thermometer and kept track of the temperature coming out of the vents in the cab. Temperature would drop by 40 deg F when the truck was at an idle and temperature out of heater vents didn't seem to correlate with engine temp?
Ford did some "cooling system" tests which they determined that the head gaskets were in fact leaking (cooling system would overpressurize under acceleration). Ford had changed out the EGR cooler a few months previously to try to resolve this issue also.
Now with new head gaskets, problem is solved, I have heat in the cab at an idle once more!!!
I too had that exact same problem with my 03 6.0l. When the engine temp. was normal and the truck was brought down to an idle, it was just like the a/c was turned on. Only noticed this problem during the cooler weather.
Truck was constantly using a small amount of antifreeze and would never stay at the "new" fullmark. Also appeared that the engine temperature would reach "normal operating" range a little faster than normal.
I bought a digital thermometer and kept track of the temperature coming out of the vents in the cab. Temperature would drop by 40 deg F when the truck was at an idle and temperature out of heater vents didn't seem to correlate with engine temp?
Ford did some "cooling system" tests which they determined that the head gaskets were in fact leaking (cooling system would overpressurize under acceleration). Ford had changed out the EGR cooler a few months previously to try to resolve this issue also.
Now with new head gaskets, problem is solved, I have heat in the cab at an idle once more!!!
Hope this helps,
Selbeep
My truck is doing a similar thing. I noticed I was a little low on coolant, and I replaced about a 1/2 gal. I'm getting a little bit of puking, and a whistling noise under hard acceleration, and sudden throttle release. The heater started working again when I re-filled the coolant, but I'm concerned about the loss of coolant. do you know what the over pressure psi was?
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2004 F-250 Lariat, srw, short bed, 4x4, Purchased in Feb. of 2006. 6.0, auto, 3.73.
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Heater Problem???????????
, Bilsteins shocks, BTS Trans, Baby 
Swamps,Tony Wildman 
Chip, AutoMeter Pyro/Trans/Boost, Tymar intake, MBRP 4 in turbo back exhaust, 209000 miles,D&B HT Starter
Linear Mode
