Keeping the engine warm

[TCluff]

my 03 wont stay warm, i have approx 75 percent of the radiator blocked with semi heavy cloth and the heater starts blowing colder as you increase the fan speed even at operating temp, replaced the rad cap and t-stat with oem from cummins, gets frustrating, let it warm up for 15 minutes and drive for 15 miles at 55mph and when i get home it can barely knock the frost off the windshield, it has been around -5 to -10 in the mornings, do i need to block the rad off with cardboard??? also if i drive more than about 35 miles at 80mph the truck hits about 220 deg but still has same heater problem, i parked the truck and have been driving a dodge neon and a ford focus, at least they blow warm air out of the vents... .

 

[Bob4x4]

Are you sure your hvac system is functioning correctly? Heater core is flowing good. Use an IR heat gun to measure the temps of the heater core in and out



Bob

 

[MickeyMiller]

TCUFF,



I originally got my truck in Billings, MT and for it's first 2 winters I kept a piece of cardboard blocking off the entire radiator. Around town, in cold weather, it wouldn't get warm without being blocked off. On the flip side, I've been up and down the Sierra's in 110* weather, with a load in the bed, and it didn't get hot either!



Block it off!



Mickey

 

[jelag]

You've got something wrong.....

Air bubble in the heater core, low on water, or AC door not working... . I own 4 of these trucks... . all put out hot air from 10 min after you start them and the heater works well down to about -15 *f without any winter front... .....

I don't use a winter front because I want the coldest air possible through the inter-cooler going to the engine.....

My wife's car was blowing cold air... . air bubble and 3/4 gal low on coolant... as soon as we burped it and added the coolant it got hot again... .

 

[rbattelle]

I agree with Jim - there's got to be a problem with the HVAC system, and possibly the heater core.

Since it will blow warm air part of the time, I would tend to point the finger at the heater core.

But how do you "burp" the system? Truck's too heavy to put over your shoulder.

Ryan

 

[MAllen1]

If there is an air bubble in your heater core, the only way I know how to get it out is to park your truck on an incline steep enough so that the top of the radiator is higher than the heater core. The two times I had that problem I solved that way. Simplistic, but, it worked.

 

[TCluff]

I WILL BLOCK THE RAD OFF AND SEE IF THAT WILL KEEP THE ENGINE AT OPERATING TEMP, AS FOR THE HEATER I THINK IT MIGHT BE A COOLANT FLOW ISSUE CAUSE IT BLOWS WARM AT LOW SPEED BUT COOLS OFF WHEN YOU TURN THE SPEED UP, IS IT A PAIN TO GET TO THE HEATER CORE

 

[SWiller]

did the 03s have the same issue as the 06s where the blend door would break? If so that might be a start?



hope this helps.

 

[Hoefler]

Make sure the supply heater hose goes to the bottom of the heater core inlet, the top is the return to the motor. Loosen the return hose while filling to make sure the air escapes. Then run it with the radiator cap on the first notch, you don't want the system to become presurrized, this will allow any air to be purged out. While you are at it, check the engine temperature while it is blowing warm air and when it goes cold, the thermostat could be bad.

 

[Skydiver]

TCluff, How much boost can you make? My first diesel truck 79 chevy (I know, poor excuse for a truck) had a head gasket start leaking and the heater stopped working. Check for bubbles in your coolant recovery tank while it's running and after it gets up to normal temp.

 

[JBallou]

Geez don't scare the man. It is probably low on coolant, and has a bobble that is as stubborn as it is cold. Does the idiot gauge inside move?

 

[TCluff]

TCluff, How much boost can you make? My first diesel truck 79 chevy (I know, poor excuse for a truck) had a head gasket start leaking and the heater stopped working. Check for bubbles in your coolant recovery tank while it's running and after it gets up to normal temp.

it will make around 80psi at 6000 ft elevation, no more worries about needing to warm it up, just blew it up this morning again, can you say the third time its blown, this motor just made it to 5,200 miles#@$%!

 

[DonFitzwater]

Your just hard on equipment... ... ... ... ... ... ... ... ... it's-39 here today and my 06 is toasty warm. :-laf