7.3 no heat

[eastcoaststroker]

i have a 03 7.3psd , i just replaced the water pump and thermostat 3 days ago and my heat will not work i have no idea what the problem could be, could anybody help me out on what it could be

[mgassel]

Originally Posted by eastcoaststroker

i have a 03 7.3psd , i just replaced the water pump and thermostat 3 days ago and my heat will not work i have no idea what the problem could be, could anybody help me out on what it could be

Did you use any stop leak in your truck prior to the water pump replacement?
If you did chances are you clogged up the heater core.

You can try to hook up a garden hose to flush it out by forcing water through the heater hose just make sure you unhook bith sides so the crap will not get into the block. If you can not get water flow throught it then you will need a new one.

Did you replace the coolant with any other type other than what was in it?
Not all coolant mixes with others no matter what the bottle says.

Did you put in the correct thermostat and put it in the correct way? If you put in the cooler one that is why you have no heat.

[ttyR2]

Does just the defrost work? If so, it may be a vac system problem

[eastcoaststroker]

Originally Posted by mgassel

Did you use any stop leak in your truck prior to the water pump replacement?
If you did chances are you clogged up the heater core.

You can try to hook up a garden hose to flush it out by forcing water through the heater hose just make sure you unhook bith sides so the crap will not get into the block. If you can not get water flow throught it then you will need a new one.

Did you replace the coolant with any other type other than what was in it?
Not all coolant mixes with others no matter what the bottle says.

Did you put in the correct thermostat and put it in the correct way? If you put in the cooler one that is why you have no heat.

There has never been any stop leak put in the truck and ive allways ran cat red antifreez in the truck the thermostat was the same size etc. Just a cheaper carquest brand

[eastcoaststroker]

Originally Posted by ttyR2

Does just the defrost work? If so, it may be a vac system problem

The heat will only work when I'm getting on it driving down the road then it will start blowing straight cold again

[wynn456]

Sounds like you may have an air bubble in there. If you sit and rev the motor do you get any heat.

[eastcoaststroker]

Originally Posted by wynn456

Sounds like you may have an air bubble in there. If you sit and rev the motor do you get any heat.

Nope just blows cold , if I'm just sitting still and reveing the motor the heat gage will hardly leave cold I let it run for prob a hour and it didn't heat up until I started driving

[MILBY]

Sounds like a thermostat prblem, or air in the system. Mine is a 01 and I put the 203 thermostat in and have all kinds of heat and the truck runs better.

[wynn456]

Ya iam going to say you got a bad t-stat

[mgassel]

Originally Posted by wynn456

Ya iam going to say you got a bad t-stat

Yeah he may have got the cooler one by no fault of his own.
Some of the people that work at part stores are idiots.

They claim to hold an ase certification for parts pro but thruthfuly maybe only one person has that.

Just because they claim OEM does not mean that it is the same or even right.
I went to one part store to buy spark plugs for my 460 and they told me oem was ac delco Needles to say I bought Motorcraft.

Kinda like the distributor I bought from a part store and the guy told me they do not sell bad parts.
The gear on the distributor was not in the correct place and I could not get it to seat properly.
I just about shoved it up his arse.
He told me I will order a new one I said no thanks since you are telling me the customer who is a trained professional that I am wrong.
I went to another part store and they told me yeah that happens all the time at that part store and he properly orded me one and it fit correctly.

So when I needed another one for another truck I went back to the part store that got me the defective free one and had no issues.