2003 Excursion - 7.3 Diesel
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2003 Excursion - 7.3 Diesel
Hi,
From the winter wonderland of Pennsylvania (by the Great Lakes). Recently purchased a 2003 Excursion, 7.3 Diesel from down South. No issues until it started getting cold. Vehicle warms up to temperature fine, but when idling (sitting at a light, etc.) the tack goes down and it loses heat. (Usually rides right in the middle). Have had it flushed 3 times. Each time we will have HOT, HOT heat for a while and then the issue starts happening again. We were told it has a "timing chain cover" leak, which the prior owner had put some kind of stop leak in to seal. When the heater core is flushed, bits and pieces of stuff come out, but then it seems to get "clogged" again.
What can we do to fix this? Were told could be air bubbles (which we have tried to get out, to no avail) - were told maybe the thermostat (but have heat with acceleration) - were told to put plexiglass/cardboard in front of the radiator to help with cold air getting in.
We need heat!!! (Supposed to be in the negatives this week).
From the winter wonderland of Pennsylvania (by the Great Lakes). Recently purchased a 2003 Excursion, 7.3 Diesel from down South. No issues until it started getting cold. Vehicle warms up to temperature fine, but when idling (sitting at a light, etc.) the tack goes down and it loses heat. (Usually rides right in the middle). Have had it flushed 3 times. Each time we will have HOT, HOT heat for a while and then the issue starts happening again. We were told it has a "timing chain cover" leak, which the prior owner had put some kind of stop leak in to seal. When the heater core is flushed, bits and pieces of stuff come out, but then it seems to get "clogged" again.
What can we do to fix this? Were told could be air bubbles (which we have tried to get out, to no avail) - were told maybe the thermostat (but have heat with acceleration) - were told to put plexiglass/cardboard in front of the radiator to help with cold air getting in.
We need heat!!! (Supposed to be in the negatives this week).
5th Wheeling
Joined: May 2006
Posts: 44
Likes: 4
I would check a couple of things. First, do both heater hoses get hot? If one is hot and the other does not get hot I would suspect a clogged heater core. I think that would be a real PITA to replace. You might try taking the hoses off and trying to backflush the core.
The other possibility that I would check is that the thermostat is sticking open. That could explain the have heat/don't have heat cycles also...
FWIW - Frank
The other possibility that I would check is that the thermostat is sticking open. That could explain the have heat/don't have heat cycles also...
FWIW - Frank
Tuned
Joined: Jun 2003
Posts: 465
Likes: 53
From: Connecticut
"When the heater core is flushed, bits and pieces of stuff come out, but then it seems to get "clogged" again."
Keep flushing. Making the radiator/engine hotter does you no good if you don't have water flowing through the heater core.
Keep flushing. Making the radiator/engine hotter does you no good if you don't have water flowing through the heater core.
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FaC: One hose does NOT get hot, which is why we also thought a plugged heater core. It has been done 4 times already within the last 3 months and is getting quite expensive. The entire system can't be flushed we are told because of the timing chain cover leak (obviously we don't want for that leak to get bigger).
As for the thermostat, I was told from a "mechanic" that diesel's are a pain in the *** to change the thermostat in.... your thoughts?
GregA: Is this a simple process to do yourself (flushing out only the heater core)? The company we have taken it to, indicates they have gotten particles out, however at over $80 a pop, it's getting expensive.
As for the thermostat, I was told from a "mechanic" that diesel's are a pain in the *** to change the thermostat in.... your thoughts?
GregA: Is this a simple process to do yourself (flushing out only the heater core)? The company we have taken it to, indicates they have gotten particles out, however at over $80 a pop, it's getting expensive.
Tuned
Joined: Jun 2003
Posts: 465
Likes: 53
From: Connecticut
Sorry, no experience...but since this is the Internet and opinions are free, maybe remove the two hoses in the engine compartment and run water or compressed air through it either way to try and blow the junk out?
Have you verified that the valve in the engine compartment is actually open? Maybe put a piece of tubing to bypass that valve to test that it's working?
Have you verified that the valve in the engine compartment is actually open? Maybe put a piece of tubing to bypass that valve to test that it's working?
Postmaster
Joined: Nov 2015
Posts: 4,807
Likes: 125
From: Colorado Springs
FaC: One hose does NOT get hot, which is why we also thought a plugged heater core. It has been done 4 times already within the last 3 months and is getting quite expensive. The entire system can't be flushed we are told because of the timing chain cover leak (obviously we don't want for that leak to get bigger).
As for the thermostat, I was told from a "mechanic" that diesel's are a pain in the *** to change the thermostat in.... your thoughts?
GregA: Is this a simple process to do yourself (flushing out only the heater core)? The company we have taken it to, indicates they have gotten particles out, however at over $80 a pop, it's getting expensive.
As for the thermostat, I was told from a "mechanic" that diesel's are a pain in the *** to change the thermostat in.... your thoughts?
GregA: Is this a simple process to do yourself (flushing out only the heater core)? The company we have taken it to, indicates they have gotten particles out, however at over $80 a pop, it's getting expensive.
Go to a different mechanic!!!!
The thermostat the 7.3L literally sits on top the water pump where it connects to the top hose. Drain radiator, remove top hose, remove thermostat housing, replace thermostat, replace housing, fill Degas bottle until you see fluid in the housing, reconnect hose, top off and go. Done, literally 30 minutes assuming that bolts are in good shape. If you're going to replace the thermostat it would be a good time to replace the thermostat housing with a nice billet one. Another option for you is to put a coolant filter on it yourself so that you're catching these particles as they circulate through the system.
Link for filter: http://www.riffraffdiesel.com/riffra...ter-kit-03-07/
Here's a video.
The thermostat the 7.3L literally sits on top the water pump where it connects to the top hose. Drain radiator, remove top hose, remove thermostat housing, replace thermostat, replace housing, fill Degas bottle until you see fluid in the housing, reconnect hose, top off and go. Done, literally 30 minutes assuming that bolts are in good shape. If you're going to replace the thermostat it would be a good time to replace the thermostat housing with a nice billet one. Another option for you is to put a coolant filter on it yourself so that you're catching these particles as they circulate through the system.
Link for filter: http://www.riffraffdiesel.com/riffra...ter-kit-03-07/
Here's a video.
Check out this video on YouTube:
Postmaster
Joined: Sep 2007
Posts: 4,195
Likes: 6
From: Medford Oregon
FaC: One hose does NOT get hot, which is why we also thought a plugged heater core. It has been done 4 times already within the last 3 months and is getting quite expensive. The entire system can't be flushed we are told because of the timing chain cover leak (obviously we don't want for that leak to get bigger).
We don't have a timing chain.
As for the thermostat, I was told from a "mechanic" that diesel's are a pain in the *** to change the thermostat in.... your thoughts?
One of the easier things to replace in the 7.3. Get another mechanic.
We don't have a timing chain.
As for the thermostat, I was told from a "mechanic" that diesel's are a pain in the *** to change the thermostat in.... your thoughts?
One of the easier things to replace in the 7.3. Get another mechanic.
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Laughing Gas
Joined: Nov 2010
Posts: 1,193
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From: D.C. but heart's in TEXAS
Good to a different mechanic!!!! The thermostat the 7.3L literally sits on top the water pump where it connects to the top hose. ...If you're going to replace the thermostat it would be a good time to replace the thermostat housing with a nice billet one. Another option for you is to put a coolant filter on it yourself so that you're catching these particles as they circulate through the system.
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Laughing Gas
Joined: May 2007
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Welcome to FTE!
Adding to the chorus for:
- Get a new mechanic. Preferably one where you see other Fords in the lot.
- Back-flush the heater core.
- Replace the thermostat and consider getting Riff Raff's billet housing (Riffraff Diesel 7.3L Billet Thermostat Housing). Also, IIRC the housing needs a gasket, so replace that as well.
- Consider installing a coolant filter
Adding to the chorus for:
- Get a new mechanic. Preferably one where you see other Fords in the lot.
- Back-flush the heater core.
- Replace the thermostat and consider getting Riff Raff's billet housing (Riffraff Diesel 7.3L Billet Thermostat Housing). Also, IIRC the housing needs a gasket, so replace that as well.
- Consider installing a coolant filter
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