heat only blowing when on the throttle

[03justin6.0]

ok so here is my problem , I have a 2003 f350 6.0 I haven't used it for any towing other then a little utility trailer so far, Iv only had it for a few weeks. when I bought the truck from day one I noticed that the heat only would blow hot when stepping on the throttle. Now only purchased this truck knowing the ARP head studs where done, as well as the egr delete. so with that being said iv been doing a lot of research on this issue and is steering me all kinds of different ways. I bought a tuner for my old 6.0 I had and I hooked it up just to diagnose the problems iv been seeing with the gauges . the EOT and the ECT are with in 15 or so degrees of each other. yet my coolant spills out my degauss bottle. there is no milky texture to it , I replaced the degas cap and filled my overflow to a little below the min line in hopes maybe it was originally over filled, and it still does it, I took it to the local garage to see if they good diagnose it , and they seem to think its a water pump issue. I see no noticeable power loss, but I have noting to go off of seeing how this issue has been around since I bought the truck, can anyone give me some advice or answers
43mph -ect 192.00,eot 209.17,boost 20.8
0mph- ect 218, eot 211.15

 

[AirFishAutomotive]

At idle its running 218/211? Was the oil cooler done?

 

[03justin6.0]

No not that I'm aware of, do you think that's the problem ?

 

[webb06]

If it's pushing coolant out of the degas bottle it's got blown head gaskets. Sucks to tell you that but there's no way around that problem.

Needs an oil cooler too it sounds like.

 

[morepower02]

I had no heat at idle once. Dealer replaced headgaskets and took care if it.

 

[03justin6.0]

I really hope not , is that the only thing it could be? It's not a white residue tho it's just coolent

 

[03justin6.0]

How is the heat related to the head gasket ?

 

[morepower02]

Low coolant causes no heat at low rpm. Your coolant is low because the cylinder psi is blowing it out the degas. You need headgaskets and heads checked for crack/warp.

 

[Bigred91]

The headgaskets cause excessive pressure in the cooling system which forces coolant out of the degas bottle. The heat runs off of the coolant. When your low on coolant your aren't getting coolant into the heater core like it should to make the air warmer. When your on the throttle it pushes the coolant through the system better causing the heat to work

 

[suprdzlduty]

The excess pressure from the combustion causes the coolant flow to "lock" or prevent consistent flow through the heater core and other areas of the engine. When the rpm comes up the water pump can overcome the "lock" and push the coolant on through.

 

[suprdzlduty]

Beat me to it lol

 

[03justin6.0]

Thanks for the info , i tried to make sure I wasn't getting my self into all these problems

 

[dutchywas]

Water pump

 

[03justin6.0]

That's what the shop told me I took it to

 

[morepower02]

Water pump

Care to elaborate on your first post here?

 

[03justin6.0]

My thought was if the water pump or oil cooler isn't working it it could be flash boiling the Coolent under a heavier engine load creating pressure blowing coolant out of the overflow

 

[morepower02]

Wishfull thinking. Good luck with your repairs.

 

[webb06]

Water pump

So what's causing the coolant loss? The water pump spinning so fast it's pushing it out? Wrong

Hook up a gauge to test the cooling system pressure. That'll tell you for sure.

 

[05stroker350]

Had this problem on my truck last year. It was the gaskets. Good luck.

 

[03justin6.0]

Well the truck is at the dealership getting a diagnostic I guess i hope for the best