Thermal Insulation

[Nicks911]

Trying to keep cool using me SC as my DD in Southern Florida. I have upgraded the AC with larger condensers front and rear upgraded evap and blower and the system can just about keep up with August in Miami heat on shorter trips. On long trips say between Miami and Tampa the AC can keep up for the first two hours or so then the heat soak from the engine bay starts to overcome the AC's ability to remove heat from the cabin. The floors and rear seats are hot to the touch. Any body have any success in keep this heat out of the cabin?

Nick

[nineball]

there are lots of solutions for stopping heat. i would suggest one of the following:

Heat Wave Pro - Acoustic Thermal Insulation and Engine Insulation Material

http://www.secondskinaudio.com/viewproduct.php?id_product=355

[RSTarga]

If you did all those upgrades properly you should not have this problem. Something is not right. Could you show us pictures and describe your upgrades?

[Nicks911]

Sorry no pics and the car is in Florida and I'm in Ecuador for the next couple of weeks. I have the complete Retro air upgrade w/ rennair's front cooler and upgraded fan. Vent temps are in the high 30's during long trip with the fan on high. Outside temp's ~100 with. Glass is not tinted. Pretty sure the issue is heat soak from the engine bay as the vent temps stay constant while the interior first cools down to be comfortable and then heats back up about 2 hrs into a trip the rear seat foot well area and seat bottoms are almost too hot to touch

[Nicks911]

Just had my friend check the front condenser fan and it is not working. Maybe this is lowering the efficiency of the system enough that the car is heating up? How hard is it to open up the housing and replace the motor?

[86 911 Targa]

Originally Posted by Nicks911

Just had my friend check the front condenser fan and it is not working. Maybe this is lowering the efficiency of the system enough that the car is heating up? How hard is it to open up the housing and replace the motor?

Nick,

Test for voltage at the fan harness.
If no voltage, check the fuse, and your A/C relays.

On the fuse panel, relay #6, the one closest to the front of the car,
and the one in the smuggler's box.

If you are getting voltage to the fan,
do not use your A/C as your fan may have seized.!!!!!

There have been fire issues.

If required, the fan motor assembly is very easy to remove/replace.

1. Remove the windshield wiper pump.

2. Remove the screws which hold down the fan assembly.

3. Disconnect the wiring harness.

4. Pull the fan out of the luggage compartment.

If your fan has seized, it may be possible to loosen it up.
Check various posts on footwell blower, and condenser fans.
The proceedure for reviving these fans is identical.

If not, look for a used fan on eBay, or this site.

You may pm me as needed.

Good luck,

Gerry

[RoninLB]

the vent that is above the rear window is constantly open

it'll take water when washing if you hose the water in there

this may be an AC issue?

[Nicks911]

Thanks for the help Gerry. I don't think I'll have any trouble getting the fan out of the car. What I was wondering about is opening up the fan housing and swapping in a new motor. How hard is it to open up the housing or is it not possible?

[86 911 Targa]

Originally Posted by Nicks911

Thanks for the help Gerry. I don't think I'll have any trouble getting the fan out of the car. What I was wondering about is opening up the fan housing and swapping in a new motor. How hard is it to open up the housing or is it not possible?

Where are you located?

[Nicks911]

Split my time between Quito Ecuador and Miami

[86 911 Targa]

Originally Posted by Nicks911

Split my time between Quito Ecuador and Miami

pm me.

[JFairman]

"Vent temps are in the high 30's during long trip with the fan on high. Outside temp's ~100 with. "

Just wanted to say, an AC vent to outside ambient temp differential like that is more than excellent in a 911 while the evaporator fan is on high... especially in S. Florida on a sunny afternoon.

The heat transfer you mentioned in the back of the car may mean the engine bay sound/thermal insulation pad needs replacing and so does the interior upper and lower rear sound pads under the rear deck and behind the rear seats and under the carpetting in back.
Thats if the motor isn't overheating in a big way.
The soundpads also help insulate engine heat from transfering into the cabin but they are alot heavier than modern replacement materials.

[86 911 Targa]

Originally Posted by Nicks911

Thanks for the help Gerry. I don't think I'll have any trouble getting the fan out of the car. What I was wondering about is opening up the fan housing and swapping in a new motor. How hard is it to open up the housing or is it not possible?

It's a no-brainer.........

The housing halves are held together by a few clips, and the motor comes off with one screw.

Do a search on footwell/condenser motor repairs.

Good luck,

Gerry

[Nicks911]

I fixed the front condenser blower and that has resulted in some improvement with city driving, however I still have trouble on the highways with the cabin heating up. One thing I have noticed is around town and driving on the highway with the rpms below 3K the vent temps stay in the mid to high 30s. More than 30 min driving above 3K and the vent temps creep up to the 40's. If I kill the rpms and coast in neutral the temps drop back to the 30's quite quickly. Thoughts?

[tcar]

Have you done the 'bowtie fix'?

There is a bowtie shaped plastic A/C diverter centered under the dash, in front of the console.

Remove it.

Better yet, put a hose on the fitting after removing it and put an aftermarket A/C vent on top of the console so you can direct cold (cool) air.


And yes, the lack of fan on the front condenser will make a noticable difference.


And, the vent above the rear window is for the flow thru ventilation. Originally there was a foam filter just inside it. Over time, the foam disintegrates, leaving it just open. Had a friend that replaced it by fishing a piece of black foam (from hardware store, for window A/C units) in thru one of the holes and positioning it with dental picks.

[911pcars]

If the A/C produces normal conditioned air and the rear seat/floor area is excessively warm, why offer suggestions to increase the A/C output to overcome the abnormal heat source? That's counterproductive as well as ass-backwards.

If you're sure the heat soak is from the engine, apply insulation material to the outside of the cabin (e.g. engine side of the chassis). There are any number of reflective, sandwich type insulation materials/coatings to apply.

With the heat source eliminated or reduced and the cabin insulated, you can then work on increasing the efficiency of the A/C system. The suggestions offered are then valid. In addition, tinting the windows can reduce the heat load produced by the sun.

Sherwood

[Nicks911]

Bow tie fix is done. I'm wondering if the system was over charged with coolant and when the engine is above 3k the compressor is generating too much pressure in the system to work effectively

[tcar]

Originally Posted by Nicks911

Bow tie fix is done. I'm wondering if the system was over charged with coolant and when the engine is above 3k the compressor is generating too much pressure in the system to work effectively

That could very well be part of the problem...

You didn't say, what is in the system, R-12 or R-134a?

I use R-12, it cools noticably better than 134 in a system designed for R-12.


I'm still wondering why your floor is so hot. Do you mean the floor in the back, by the engine?

The only floor that gets warm in my SC is on the passenger side just above the oil lines to the cooler.

[zippy_gg]

I am wondering if one or both of your heat exchanger duct might be leaking inside your car. This would explain more heat with higher RPMs... Just thinking aloud here...