Neighbors Siverado has no heat
Thread Starter
Registered User
Joined: Jan 2010
Posts: 6,120
From: central Indiana
Neighbors Siverado has no heat
My neighbor has a 01 Siverado with the 5.3, A/C, that has zero heat. I mean ice cold air comes from any of the vents.
First, I verified the actual engine temp with a scan tool. Fully warmed up, temp is around 190-195. No problem there.Since the air is ice cold with zero heat, I then move to the temp door actuator. While the actuator will move with changes to the temp dial, I can easily stop the movement with my fingers. I assumed that was the issue, so I replaced it. No change. I then moved to the heater core, while the hoses weee warm, there was a noticeable difference between the temp of the heater hoses and the upper radiator hose. I suspected a restriction, so I flushed out the cooling system and specifically the heater core. There was lots of crud that came from the heater core, unpin reassembly the hoses were all the same temp, big improvement in heater hose temp, however still no heat. I then went back to the temp door, I removed the actuator again, I can move the temp door with my fingers and hear it hit each stop in its travel, but no change in heat.
At this point, I’m kinda stumped. I suspect something inside the heater case. To the best of my knowledge, that truck doesn’t have a cabin air filter. I’m suspicious of airflow, while the blower motor makes a bunch of noise, the airflow isn’t all that strong. Any ideas? Can anyone in readerland think of something I’ve overlooked?
My neighbor will have trouble rubbing 2 nickels together now, so I’m trying to help him out as much as I can. This is his only means of transportation, and this is the wrong time of year to have no heat. Thanks!!
First, I verified the actual engine temp with a scan tool. Fully warmed up, temp is around 190-195. No problem there.Since the air is ice cold with zero heat, I then move to the temp door actuator. While the actuator will move with changes to the temp dial, I can easily stop the movement with my fingers. I assumed that was the issue, so I replaced it. No change. I then moved to the heater core, while the hoses weee warm, there was a noticeable difference between the temp of the heater hoses and the upper radiator hose. I suspected a restriction, so I flushed out the cooling system and specifically the heater core. There was lots of crud that came from the heater core, unpin reassembly the hoses were all the same temp, big improvement in heater hose temp, however still no heat. I then went back to the temp door, I removed the actuator again, I can move the temp door with my fingers and hear it hit each stop in its travel, but no change in heat.
At this point, I’m kinda stumped. I suspect something inside the heater case. To the best of my knowledge, that truck doesn’t have a cabin air filter. I’m suspicious of airflow, while the blower motor makes a bunch of noise, the airflow isn’t all that strong. Any ideas? Can anyone in readerland think of something I’ve overlooked?
My neighbor will have trouble rubbing 2 nickels together now, so I’m trying to help him out as much as I can. This is his only means of transportation, and this is the wrong time of year to have no heat. Thanks!!
Registered User
Joined: Jul 2014
Posts: 421
From: Imlay City, Michigan
Hi,
Does the heater controls cycle through all the position as I know Dodge used a blend door motor that would go bad, not sure how GM's of that era handle this but good place to start.
Other thing to check is the heater core plugged?
Good luck.
Regards,,
Jim
Does the heater controls cycle through all the position as I know Dodge used a blend door motor that would go bad, not sure how GM's of that era handle this but good place to start.
Other thing to check is the heater core plugged?
Good luck.
Regards,,
Jim
Registered User
Joined: Mar 2012
Posts: 27
From: So Cal
My 2017 Ford F150 had a similar problem. Online I saw a suggestion to check coolant level. Sure enough the large overflow was bone dry. I filled it and the heater started working. Discovered later that the water pump was leaking. Haven’t had a problem with heater since.
Moderator
Joined: Jul 2007
Posts: 18,266
From: Edmond, OK
The heater in my 96 Oldsmobile 98 stopped working and it was the blend door actuator behind the glove box on top of the AC plenum. You mentioned that you replaced one of those air door actuators already. Might it be a different actuator that's bad?
Last edited by Olds64; Nov 25, 2024 at 02:25 AM.
Thread Starter
Registered User
Joined: Jan 2010
Posts: 6,120
From: central Indiana
Good news, and I think I created a new problem.
The truck does in fact have a cabin air filter, that had never been changed. Truck only has 220k on it! It took some effort to wrestle the clogged and packed full of cud filter, plus clean up the mess on the floorboard. However, the truck now has blast furnace heat, with much better airflow.
The new issue: the only way to have heat is to put the temp dial on cold. Put the dial on hot, you get cold air. I appear to have somehow installed the temp door actuator180 out of time. Hopefully an easy fix for another day.
The truck does in fact have a cabin air filter, that had never been changed. Truck only has 220k on it! It took some effort to wrestle the clogged and packed full of cud filter, plus clean up the mess on the floorboard. However, the truck now has blast furnace heat, with much better airflow.
The new issue: the only way to have heat is to put the temp dial on cold. Put the dial on hot, you get cold air. I appear to have somehow installed the temp door actuator180 out of time. Hopefully an easy fix for another day.
Thread
Thread Starter
Forum
Replies
Last Post
