Interior heat
10-03-2007, 01:14 AM
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Interior heat
I finally got my over heating issue resolved and I've finally been able to drive the car a bit. One of the parts I have to replace/trouble shoot is the blower motor for the A/C. So I currently have no heat or A/C. I've noticed that the interior gets really hot compaired to my other non Porsche cars. Is this normal? What's your guys opinion? Jason
10-03-2007, 02:50 AM
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The 928 has lots of glass, which certainly doesn't help the temperatures in the interior in the sun...
But you may also have a non-functioning heater valve. Remove the air box and have somebody watch that valve as you start the car. With the temperature set on cold, this valve should move (close) when you start the engine. If it does not move, you may have a vacuum problem. If it moves, and you still get warm air while driving, then either the valve does not seal, or you have some other HVAC problem.
But the heater valve is always the place to start, I would say.
But you may also have a non-functioning heater valve. Remove the air box and have somebody watch that valve as you start the car. With the temperature set on cold, this valve should move (close) when you start the engine. If it does not move, you may have a vacuum problem. If it moves, and you still get warm air while driving, then either the valve does not seal, or you have some other HVAC problem.
But the heater valve is always the place to start, I would say.
10-03-2007, 03:51 AM
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I just replaced the heater valve when I was working the over heating issue(The old one split). What I was actually meaning was warm not from the vent but the interior heating up from the motor and exhaust getting warm. Jason
10-03-2007, 07:29 AM
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Yes it does get warm pretty quickly inside - but again depending on climate and weather. When cold/cool weather I don't notice it, but when the sun shines..
..one other thing: is your recirculation flap working?
..one other thing: is your recirculation flap working?
10-03-2007, 07:52 AM
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When your motor mounts get weak, the seal between the torque tube/shifter area might not be tight anymore and let additional warm air into the car. I'm not sure this applies to automatics, though...
10-06-2007, 05:38 PM
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I've experienced the same thing in my '91 GT. The heat seems to radiate from the engine wall. I'm new to 928s and assumed this was normal.
10-06-2007, 05:41 PM
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10-06-2007, 05:55 PM
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Once the car is warmed up, open the windows and sunroof and driver around. If your mounts are collapsed and heat is entering from the engine bay, you'll be able to feel heat from the shifter area and center console. Opening the sunroof creats a vacuum effect the pulls more heat in.
10-06-2007, 08:29 PM
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Once the car is warmed up, open the windows and sunroof and driver around. If your mounts are collapsed and heat is entering from the engine bay, you'll be able to feel heat from the shifter area and center console. Opening the sunroof creats a vacuum effect the pulls more heat in.
I have no sunroof. Does this apply to automatics as well? Jason
10-06-2007, 08:31 PM
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I'm not sure that's the cause, but my 82 A/T gets really, really warm around the console and shifter.
10-07-2007, 12:04 AM
#12
There is a noticeable heat radiating from my console. For a while I mistakenly thought this was a heater valve issue, but the (new) heater valve works correctly. The console area heat is from engine radiation, akin to what Nicole had described. If you have a new heater valve, then resolve *any* vacuum leaks. Trace vacuum hoses and make sure that the hoses are continuous without perforations and check the vacuum line elbows for proper fitting.
Mike
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10-07-2007, 04:35 AM
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The majority of these cars leak heat either through the firewall or up through the shifter (five speed and auto). There are several things to check.
1. There is a rubber gasket between the engine compartment and the HVAC system. If this gasket is missing then heat from the engine will get into the ventilation system and heat up inside the car. On the newer cars there are a couple of rubber bumpers on the side of the heater compartment on the fenders. You know the funny looking things. These also prevent heat from gettting inside.
The next place to look are the gromets through the fire wall. On older cars then come loose. Radio and alarm installers often punch holes through the firewall. Check all these places and make sure you have a good seal. Even a small hole will let in a lot of heat.
The biggest source of excess heat is the foam rubber seal on the torque tube. They all shrink over time. Maybe gaps are caused by bad motor mounts, but my 85 has new mounts and I was getting tons of heat through the center console. The cure is to get a spray faom instlation can from Home Depot and spray a little between the shifter and the foam rubber boot. The extra insulation will seal up the space. Do not use too much because it expands. I continued to operate the shifter when the foam was expanding.
Before the treatment the A/C was marginal. After, I now run the A/C even on hot days on low and periodically turn it off because it is too cold. Best I am now no longer getting road engine fumes. The car even smells better. After sitting in the sun a couple of hours I return to the smell of nice leater and not oily residue.
Check for the proper heat shields over the exhaust. The Euro cars had a non insulated center panel. On US cars the center panel is insulated because of the cats. Upgrading this panel on the Euro cars will limit the heat broadcast to the inside of the car. Often other smaller panels are left off. Porsche put the shields on for a reason.
The car came from the factory with foam pads under the carpets. The pads serve two purposes - to keep heat out and to make a nice soft landing for your feet. Most of these pads have long sicne rotted and been discarded. If you feel the floor of the car there will be a lot of heat transfer. I found bubble pack under the carpets both insulates the carpet and provides a similar feel. Bubble pack is cheap and can be purchased at the local hardware store. It is the same material used to insulate a hot water heater. The aluminum foil makes the material near fireproof.
Finally there is tinting the rear windows.
Hope this helps
Dan the Pod Guy with a nice cool interior.
1. There is a rubber gasket between the engine compartment and the HVAC system. If this gasket is missing then heat from the engine will get into the ventilation system and heat up inside the car. On the newer cars there are a couple of rubber bumpers on the side of the heater compartment on the fenders. You know the funny looking things. These also prevent heat from gettting inside.
The next place to look are the gromets through the fire wall. On older cars then come loose. Radio and alarm installers often punch holes through the firewall. Check all these places and make sure you have a good seal. Even a small hole will let in a lot of heat.
The biggest source of excess heat is the foam rubber seal on the torque tube. They all shrink over time. Maybe gaps are caused by bad motor mounts, but my 85 has new mounts and I was getting tons of heat through the center console. The cure is to get a spray faom instlation can from Home Depot and spray a little between the shifter and the foam rubber boot. The extra insulation will seal up the space. Do not use too much because it expands. I continued to operate the shifter when the foam was expanding.
Before the treatment the A/C was marginal. After, I now run the A/C even on hot days on low and periodically turn it off because it is too cold. Best I am now no longer getting road engine fumes. The car even smells better. After sitting in the sun a couple of hours I return to the smell of nice leater and not oily residue.
Check for the proper heat shields over the exhaust. The Euro cars had a non insulated center panel. On US cars the center panel is insulated because of the cats. Upgrading this panel on the Euro cars will limit the heat broadcast to the inside of the car. Often other smaller panels are left off. Porsche put the shields on for a reason.
The car came from the factory with foam pads under the carpets. The pads serve two purposes - to keep heat out and to make a nice soft landing for your feet. Most of these pads have long sicne rotted and been discarded. If you feel the floor of the car there will be a lot of heat transfer. I found bubble pack under the carpets both insulates the carpet and provides a similar feel. Bubble pack is cheap and can be purchased at the local hardware store. It is the same material used to insulate a hot water heater. The aluminum foil makes the material near fireproof.
Finally there is tinting the rear windows.
Hope this helps
Dan the Pod Guy with a nice cool interior.
10-07-2007, 05:00 AM
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The majority of these cars leak heat either through the firewall or up through the shifter (five speed and auto). There are several things to check.
1. There is a rubber gasket between the engine compartment and the HVAC system. If this gasket is missing then heat from the engine will get into the ventilation system and heat up inside the car. On the newer cars there are a couple of rubber bumpers on the side of the heater compartment on the fenders. You know the funny looking things. These also prevent heat from gettting inside.
The next place to look are the gromets through the fire wall. On older cars then come loose. Radio and alarm installers often punch holes through the firewall. Check all these places and make sure you have a good seal. Even a small hole will let in a lot of heat.
The biggest source of excess heat is the foam rubber seal on the torque tube. They all shrink over time. Maybe gaps are caused by bad motor mounts, but my 85 has new mounts and I was getting tons of heat through the center console. The cure is to get a spray faom instlation can from Home Depot and spray a little between the shifter and the foam rubber boot. The extra insulation will seal up the space. Do not use too much because it expands. I continued to operate the shifter when the foam was expanding.
Before the treatment the A/C was marginal. After, I now run the A/C even on hot days on low and periodically turn it off because it is too cold. Best I am now no longer getting road engine fumes. The car even smells better. After sitting in the sun a couple of hours I return to the smell of nice leater and not oily residue.
Check for the proper heat shields over the exhaust. The Euro cars had a non insulated center panel. On US cars the center panel is insulated because of the cats. Upgrading this panel on the Euro cars will limit the heat broadcast to the inside of the car. Often other smaller panels are left off. Porsche put the shields on for a reason.
The car came from the factory with foam pads under the carpets. The pads serve two purposes - to keep heat out and to make a nice soft landing for your feet. Most of these pads have long sicne rotted and been discarded. If you feel the floor of the car there will be a lot of heat transfer. I found bubble pack under the carpets both insulates the carpet and provides a similar feel. Bubble pack is cheap and can be purchased at the local hardware store. It is the same material used to insulate a hot water heater. The aluminum foil makes the material near fireproof.
Finally there is tinting the rear windows.
Hope this helps
Dan the Pod Guy with a nice cool interior.
1. There is a rubber gasket between the engine compartment and the HVAC system. If this gasket is missing then heat from the engine will get into the ventilation system and heat up inside the car. On the newer cars there are a couple of rubber bumpers on the side of the heater compartment on the fenders. You know the funny looking things. These also prevent heat from gettting inside.
The next place to look are the gromets through the fire wall. On older cars then come loose. Radio and alarm installers often punch holes through the firewall. Check all these places and make sure you have a good seal. Even a small hole will let in a lot of heat.
The biggest source of excess heat is the foam rubber seal on the torque tube. They all shrink over time. Maybe gaps are caused by bad motor mounts, but my 85 has new mounts and I was getting tons of heat through the center console. The cure is to get a spray faom instlation can from Home Depot and spray a little between the shifter and the foam rubber boot. The extra insulation will seal up the space. Do not use too much because it expands. I continued to operate the shifter when the foam was expanding.
Before the treatment the A/C was marginal. After, I now run the A/C even on hot days on low and periodically turn it off because it is too cold. Best I am now no longer getting road engine fumes. The car even smells better. After sitting in the sun a couple of hours I return to the smell of nice leater and not oily residue.
Check for the proper heat shields over the exhaust. The Euro cars had a non insulated center panel. On US cars the center panel is insulated because of the cats. Upgrading this panel on the Euro cars will limit the heat broadcast to the inside of the car. Often other smaller panels are left off. Porsche put the shields on for a reason.
The car came from the factory with foam pads under the carpets. The pads serve two purposes - to keep heat out and to make a nice soft landing for your feet. Most of these pads have long sicne rotted and been discarded. If you feel the floor of the car there will be a lot of heat transfer. I found bubble pack under the carpets both insulates the carpet and provides a similar feel. Bubble pack is cheap and can be purchased at the local hardware store. It is the same material used to insulate a hot water heater. The aluminum foil makes the material near fireproof.
Finally there is tinting the rear windows.
Hope this helps
Dan the Pod Guy with a nice cool interior.
10-07-2007, 06:02 PM
#15
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The foam pad below the shifter can be new and still leak hot air. I had a new pad installed when the transmission was out and it made zero difference. My car is an automatic. I was told my mounts were O.K. but they absolutely are NOT OK. They are resting on the pan. My radio ***** and window switches will get so hot they can't be touched with a bare hand, and the radio will actually shut down, if the windows or the sunroof are open. I considered the expandable foam thing, but am simply planning to replace my mounts with solid mounts and then use foam if necessary.