Running Hot, UPDATED: Solved!
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Legend
Joined: May 2005
Posts: 8,663
Likes: 8
From: Central Oklahoma
RE: Overheating
ORIGINAL: flintspirit
My 96 is a pain to bleed the cooling system ,so what I do is leave it sitting overnight witrh the rad cap off then in the morning look to see if it's down.You may have to do this a couple times.With mine if there's an air pocket in the system I will here water trickling in my heater core when I rev the engine.
My 96 is a pain to bleed the cooling system ,so what I do is leave it sitting overnight witrh the rad cap off then in the morning look to see if it's down.You may have to do this a couple times.With mine if there's an air pocket in the system I will here water trickling in my heater core when I rev the engine.
Captain
Joined: Mar 2007
Posts: 632
Likes: 1
From:
RE: Overheating
I put my truck on a steep incline, (or you could put it on ramps or jack it up as hi as you can get it) remove the radiator cap, start the engine and all the air bubbles out the top of the radiator. When the bubbles stop air is out.
Rookie
Joined: Oct 2005
Posts: 69
Likes: 0
From:
RE: Overheating
The way the system was designed creates the air pocket problems. The Rad Cap is below the the highest point in the cooling system (heater core)....................those engineers......[8D]
I recomend a 20lb rad cap to replace the 16lb rad cap you have (i assume you have....), this willraise the boiling point of the coolant (it will stay cooler longer and stay in the system not go to the overflow)
Also buyalargetransmission cooler, shouldn't be towing w/o one
I recomend a 20lb rad cap to replace the 16lb rad cap you have (i assume you have....), this willraise the boiling point of the coolant (it will stay cooler longer and stay in the system not go to the overflow)
Also buyalargetransmission cooler, shouldn't be towing w/o one
Thread Starter
|
Legend
Joined: May 2005
Posts: 8,663
Likes: 8
From: Central Oklahoma
RE: Overheating
ORIGINAL: QuadCab318
The way the system was designed creates the air pocket problems. The Rad Cap is below the the highest point in the cooling system (heater core)....................those engineers......[8D]
I recomend a 20lb rad cap to replace the 16lb rad cap you have (i assume you have....), this willraise the boiling point of the coolant (it will stay cooler longer and stay in the system not go to the overflow)
Also buyalargetransmission cooler, shouldn't be towing w/o one
The way the system was designed creates the air pocket problems. The Rad Cap is below the the highest point in the cooling system (heater core)....................those engineers......[8D]
I recomend a 20lb rad cap to replace the 16lb rad cap you have (i assume you have....), this willraise the boiling point of the coolant (it will stay cooler longer and stay in the system not go to the overflow)
Also buyalargetransmission cooler, shouldn't be towing w/o one
I will add a cooler when I rebuild the transmission, which (knock on wood) will be this fall.
Captain
Joined: Mar 2007
Posts: 632
Likes: 1
From:
RE: Overheating
ORIGINAL: WayneC
Well as far as no heat, try this.
Warm the engine, turn on the heater, wait a moment and feel the two heater hoses. If one is hot and one is not, then the heater core/hose(s) be plugged. It's possible to have a plugged component like heater core and still have good radiator pressure.
WC
Well as far as no heat, try this.
Warm the engine, turn on the heater, wait a moment and feel the two heater hoses. If one is hot and one is not, then the heater core/hose(s) be plugged. It's possible to have a plugged component like heater core and still have good radiator pressure.
WC
Captain
Joined: May 2007
Posts: 601
Likes: 3
From: Clearwater, FL
RE: Overheating
Always flows through. Thats why when you use the VENT it's always warm. I installed a vac operated valve on mine and am not sorry. But, I did it for optimum a/c output in FL summer. The way this system is desgned, ALL air flows through the a/c evap. then a door to the heater core (or around it depending on settings) and then, finally through the rest of the HVAC system to the cab. But, the point is, The inside of the HVAC box ALWAYS has heat in it! I found out by trying to locate the cause of a passenger side air bag problem after an evap. replacement. (turned out to be a plug-in that I missed). The engine was still warm and when I took out the glove box, I actually burned myself on the casing of the HVAC box; it was still that hot!
If you want to go the route of adding a valve, you need to also tee a vacuum line under the dash and if you want I can give you the particulars on that later. I just asked at the parts desk for a vac operated heater valve for the size heater hose I have (which if I recall is 5/8")and $8 later was a happy scooter!
If you want to go the route of adding a valve, you need to also tee a vacuum line under the dash and if you want I can give you the particulars on that later. I just asked at the parts desk for a vac operated heater valve for the size heater hose I have (which if I recall is 5/8")and $8 later was a happy scooter!
Thread Starter
|
Legend
Joined: May 2005
Posts: 8,663
Likes: 8
From: Central Oklahoma
RE: Overheating
ORIGINAL: WayneC
Always flows through. Thats why when you use the VENT it's always warm. I installed a vac operated valve on mine and am not sorry. But, I did it for optimum a/c output in FL summer. The way this system is desgned, ALL air flows through the a/c evap. then a door to the heater core (or around it depending on settings) and then, finally through the rest of the HVAC system to the cab. But, the point is, The inside of the HVAC box ALWAYS has heat in it! I found out by trying to locate the cause of a passenger side air bag problem after an evap. replacement. (turned out to be a plug-in that I missed). The engine was still warm and when I took out the glove box, I actually burned myself on the casing of the HVAC box; it was still that hot!
If you want to go the route of adding a valve, you need to also tee a vacuum line under the dash and if you want I can give you the particulars on that later. I just asked at the parts desk for a vac operated heater valve for the size heater hose I have (which if I recall is 5/8")and $8 later was a happy scooter!
Always flows through. Thats why when you use the VENT it's always warm. I installed a vac operated valve on mine and am not sorry. But, I did it for optimum a/c output in FL summer. The way this system is desgned, ALL air flows through the a/c evap. then a door to the heater core (or around it depending on settings) and then, finally through the rest of the HVAC system to the cab. But, the point is, The inside of the HVAC box ALWAYS has heat in it! I found out by trying to locate the cause of a passenger side air bag problem after an evap. replacement. (turned out to be a plug-in that I missed). The engine was still warm and when I took out the glove box, I actually burned myself on the casing of the HVAC box; it was still that hot!
If you want to go the route of adding a valve, you need to also tee a vacuum line under the dash and if you want I can give you the particulars on that later. I just asked at the parts desk for a vac operated heater valve for the size heater hose I have (which if I recall is 5/8")and $8 later was a happy scooter!
Captain
Joined: May 2007
Posts: 601
Likes: 3
From: Clearwater, FL
RE: Overheating
Simple Heater / A/C Modification
This mod. will add a vacuum operated heater valve that will block hot engine coolant flowing through the heater core when it isn't wanted. Why would you want this? If you've ever tried to use the Vent function of your system on a not cold-not hot day; just wanting fresh air, only to feel warmer than outside air blowing on you, then you want this. Also, it will make your a/c blow 5-10 degrees colder by not allowing hot air into the ductwork to begin with. So here it is.
Start with the easy part; that is go to the auto parts place and ask for a vacuum operated heater valve to fit the heater hose in your truck. Sorry, can't give a particular brand or application as I did this several years ago and didn't keep that info. But the one I ended up with was $8. Cut the heater hose going from the firewall to the top of the engine on the right side and install the valve using hose clamps. In my case on the '01 my heater hose had a break in it and clamped at that fitting. I just removed the fitting and reused the clamps. Pay attention to any flow direction the valve may have. It should be noted here that when it comes time to flush the cooling system, you can simply remove the valve and install one of the Prestone flush kits in its place then replace it when you're done.
Next we'll move inside the cab and under the dash in the center against the firewall. You'll see the heat- a/c control vacuum manifold with its various colored tubes coming from it. Look for the YELLOW tube that goes a short distance to the blend door motor. (see photo) What you will do is to remove the fitting from this vac motor and install an appropriate sized tee fitting from the auto parts store. From the tee, install a 90 degree ell (also from the auto parts store) to the vac motor. From the remaining tee branch, install a section of tubing that will go out through the firewall and into the heater valve. You may need to use an adapter as I did or if you get lucky you may be able to go straight into the valve. That's it! You're done!
Now, how does it work. Pretty damn well!
But, seriously, when you want heat move your controls to the heat position. A/C...to the a/c position. The system will work almost like before but does not mix hot and cold air. What this means is, in the a/c position there will be no blending and the temperature control needs to be all the way cold. In the heat position the temp. control needs to be in the full hot position. You can play with the temp control all you want but it will only provide heat OR cool depending on the selected FUNCTION. After 3 or so years this has never been a problem for me. I either want heat or cool not warmish or coolish. When you want VENT the air will come out at the same temperature as the outside air...amazing! Now, lets say you want to turn the heater off. If you had the heater or defroster on and now want to shut it down, you can move the function to VENT and leave the temp. control at full hot and in a few moments the heater core will give up all its heat and stay cool till next time. No residual heat left to warm the cab again.
Now you can do this another way and retain FULL FUNCTION of the controls. You do this by not messing with the vac lines for the heater system and instead tee a separate vac line from the heater valve to a vac source and into the cab. Here you will use an inexpensive aquarium valve to control the heater valve. But this requires a place to mount the valve and something else to switch when you want heat or not. Tacky but do-able.
Hope I didn't leave anything out and I gotta admit, I have no idea if the photos uploaded correctly. But let me know if you have any questions.
[IMG]local://upfiles/63734/134AB67A351F4E3CACE107EC15D9AE2F.jpg[/IMG]
[IMG]local://upfiles/63734/C6AB583EBA9645C58BFDCD9791F3E0E6.jpg[/IMG]
[IMG]local://upfiles/63734/0E5177C0ED8A461B94B1BF441618A8C7.jpg[/IMG]
[IMG]local://upfiles/63734/0DA0465044F545ACA3E8AB14CBE7444E.jpg[/IMG]
This mod. will add a vacuum operated heater valve that will block hot engine coolant flowing through the heater core when it isn't wanted. Why would you want this? If you've ever tried to use the Vent function of your system on a not cold-not hot day; just wanting fresh air, only to feel warmer than outside air blowing on you, then you want this. Also, it will make your a/c blow 5-10 degrees colder by not allowing hot air into the ductwork to begin with. So here it is.
Start with the easy part; that is go to the auto parts place and ask for a vacuum operated heater valve to fit the heater hose in your truck. Sorry, can't give a particular brand or application as I did this several years ago and didn't keep that info. But the one I ended up with was $8. Cut the heater hose going from the firewall to the top of the engine on the right side and install the valve using hose clamps. In my case on the '01 my heater hose had a break in it and clamped at that fitting. I just removed the fitting and reused the clamps. Pay attention to any flow direction the valve may have. It should be noted here that when it comes time to flush the cooling system, you can simply remove the valve and install one of the Prestone flush kits in its place then replace it when you're done.
Next we'll move inside the cab and under the dash in the center against the firewall. You'll see the heat- a/c control vacuum manifold with its various colored tubes coming from it. Look for the YELLOW tube that goes a short distance to the blend door motor. (see photo) What you will do is to remove the fitting from this vac motor and install an appropriate sized tee fitting from the auto parts store. From the tee, install a 90 degree ell (also from the auto parts store) to the vac motor. From the remaining tee branch, install a section of tubing that will go out through the firewall and into the heater valve. You may need to use an adapter as I did or if you get lucky you may be able to go straight into the valve. That's it! You're done!
Now, how does it work. Pretty damn well!
But, seriously, when you want heat move your controls to the heat position. A/C...to the a/c position. The system will work almost like before but does not mix hot and cold air. What this means is, in the a/c position there will be no blending and the temperature control needs to be all the way cold. In the heat position the temp. control needs to be in the full hot position. You can play with the temp control all you want but it will only provide heat OR cool depending on the selected FUNCTION. After 3 or so years this has never been a problem for me. I either want heat or cool not warmish or coolish. When you want VENT the air will come out at the same temperature as the outside air...amazing! Now, lets say you want to turn the heater off. If you had the heater or defroster on and now want to shut it down, you can move the function to VENT and leave the temp. control at full hot and in a few moments the heater core will give up all its heat and stay cool till next time. No residual heat left to warm the cab again.
Now you can do this another way and retain FULL FUNCTION of the controls. You do this by not messing with the vac lines for the heater system and instead tee a separate vac line from the heater valve to a vac source and into the cab. Here you will use an inexpensive aquarium valve to control the heater valve. But this requires a place to mount the valve and something else to switch when you want heat or not. Tacky but do-able.
Hope I didn't leave anything out and I gotta admit, I have no idea if the photos uploaded correctly. But let me know if you have any questions.
[IMG]local://upfiles/63734/134AB67A351F4E3CACE107EC15D9AE2F.jpg[/IMG]
[IMG]local://upfiles/63734/C6AB583EBA9645C58BFDCD9791F3E0E6.jpg[/IMG]
[IMG]local://upfiles/63734/0E5177C0ED8A461B94B1BF441618A8C7.jpg[/IMG]
[IMG]local://upfiles/63734/0DA0465044F545ACA3E8AB14CBE7444E.jpg[/IMG]
