Heat issue!
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Heat issue!
2001 5.4l, when at normal op temp I can get heat for about 45 seconds and then it goes cold, turn it off and it will build back up after about a minute and then repeat the process. If I floor it, 0-60 I get a burst of heat around 50mph, let off and it goes cold. Shift to neutral and hold it at about 3,000rpms and I'll get some heat.
I WAS low about half a gallon of coolant, added some. I had a intake manifold gasket leaking a few months ago, so it was missing some fluid, no i have not burped the system and I don't know if the techs did, so I will try that tonight.
Looking for any input! Thanks.
I WAS low about half a gallon of coolant, added some. I had a intake manifold gasket leaking a few months ago, so it was missing some fluid, no i have not burped the system and I don't know if the techs did, so I will try that tonight.
Looking for any input! Thanks.
Posting Guru
Joined: Jun 2009
Posts: 1,908
Likes: 20
From: Fort Smith, Arkansas
Intermittent heat can be caused by a broken blend door or actuator motor.
If it never gets HOT, it could be a stuck open or missing thermostat and bad water pump, or restriction somewhere in the cooling system. You will want to verify that the heater hoses are both getting hot when the engine is up to full operating temperature. And definitely burp it first before you go any further on it.
If it never gets HOT, it could be a stuck open or missing thermostat and bad water pump, or restriction somewhere in the cooling system. You will want to verify that the heater hoses are both getting hot when the engine is up to full operating temperature. And definitely burp it first before you go any further on it.
Thread Starter
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New User
Joined: Oct 2017
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Intermittent heat can be caused by a broken blend door or actuator motor.
If it never gets HOT, it could be a stuck open or missing thermostat and bad water pump, or restriction somewhere in the cooling system. You will want to verify that the heater hoses are both getting hot when the engine is up to full operating temperature. And definitely burp it first before you go any further on it.
If it never gets HOT, it could be a stuck open or missing thermostat and bad water pump, or restriction somewhere in the cooling system. You will want to verify that the heater hoses are both getting hot when the engine is up to full operating temperature. And definitely burp it first before you go any further on it.
Quick question on this truck on a side note, I can burp the system simply by opening the reservoir cap since it's a pressurized system correct?
Logistics Pro
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
If one hose is hotter than the other the flow through the heater core maybe restricted.
When was the heater core last back flushed.
Flooring it could cause a broken blend door to swing between heat and no heat when accelerating and decelerating.
I think it should pretty well self burp. Is there a bleeder valve near the thermostat to let any air out?
When was the heater core last back flushed.
Flooring it could cause a broken blend door to swing between heat and no heat when accelerating and decelerating.
I think it should pretty well self burp. Is there a bleeder valve near the thermostat to let any air out?
Thread Starter
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New User
Joined: Oct 2017
Posts: 17
Likes: 0
If one hose is hotter than the other the flow through the heater core maybe restricted.
When was the heater core last back flushed.
Flooring it could cause a broken blend door to swing between heat and no heat when accelerating and decelerating.
I think it should pretty well self burp. Is there a bleeder valve near the thermostat to let any air out?
When was the heater core last back flushed.
Flooring it could cause a broken blend door to swing between heat and no heat when accelerating and decelerating.
I think it should pretty well self burp. Is there a bleeder valve near the thermostat to let any air out?
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New User
Joined: Oct 2017
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Also add that I can tell the fluid hasn't been changed out before. Planning to do that this weekend but I want to get this issue fixed before putting fresh fluid in. Atleast blow the heater core clean before swapping fluid.
Logistics Pro
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
I recommend removing at least the block drain on the driver’s side to get all the sediment that collects in the lowest portion of the block. (When I got my Navigator I drained the block, filled with water, ran engine to Luke warm, drain block - repeat until water comes out clean. I had to repeat EIGHT times before water came out clean!)
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98expedition98
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Mar 10, 2007 09:04 PM
