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Posted (edited)

Yesterday my interior heater was working, this morning when I went driving there is no heat or hot air blowing from the vents. Air is blowing from vents but not hot/warm.

Can anyone tell me what I need to check for or do? is it a simple fix like a fuse?

thanks for your help please

Edited by dedes
Posted

fan isn't working ,or ?

Yesterday my interior heater was working, this morning when I went driving there is no heat or hot air blowing from the vents.

Can anyone tell me what I need to check for or do? is it a simple fix like a fuse?

thanks for your help please

Posted (edited)

Thanks juniinc

How do I check for the fan? Isn't that outside in the front area of the car? What side of car? I should be able to hear it right?

Do you think the fan for heater has stopped?

Edited by dedes
Posted (edited)

hey dedes, I was referring to heater vent

How do I check for the fan? Isn't that outside in front of the car? I should be able to hear it right?

Do you think the fan for heater has stopped?

fan isn't working ,or ?
Yesterday my interior heater was working, this morning when I went driving there is no heat or hot air blowing from the vents.

Can anyone tell me what I need to check for or do? is it a simple fix like a fuse?

thanks for your help please

Edited by juniinc
Posted (edited)

thanks

Air is blowing from vents but not hot/warm.

i am new to this heater problem so please tell me if you know what i need to be looking for directly

i am confused

Edited by dedes
Posted (edited)

I hope , your head gasket isn't blown.

have u checked your engine oil recently?

most likely, the heater core needs to be replaced

Edited by juniinc
Posted
I hope , your head gasket isn't blown.

have u checked your engine oil recently?

Oil is full

Engine temp is normal 180

Posted

have u pulled the dip stick?

I hope , your head gasket isn't blown.

have u checked your engine oil recently?

Oil is full

Engine temp is normal 180

Posted
thanks

Air is blowing from vents but not hot/warm.

i am new to this heater problem so please tell me if you know what i need to be looking for directly

i am confused

hey dedes, I was referring to heater vent

How do I check for the fan? Isn't that outside in front of the car? I should be able to hear it right?

Do you think the fan for heater has stopped?

fan isn't working ,or ?
Yesterday my interior heater was working, this morning when I went driving there is no heat or hot air blowing from the vents.

Can anyone tell me what I need to check for or do? is it a simple fix like a fuse?

thanks for your help please

Dedes:

The fan ("blower motor") that blows either hot or cold air into the cabin is located under the dashboard, at the passenger's (right) side.

Here is a diagram of the blower motor (part #8) and its housing, along with the heater core (part #2), through which hot coolant must flow, to produce hot air into the cabin:

post-6627-1200190826_thumb.jpg

Please clarify whether, when you put your heater blower speed at the highest setting, you get a lot of air blowing through the vents, except that the air is cold, and whether, when you lower the blower speed setting, less air is blowing through the vents.

Regards, Maurice.

Posted (edited)

I will check it tomorrow morning. I do check the dip stick.

Edited by dedes
Posted (edited)

Thanks Maurice

ok, when I turn up the heater blower (highest) I get a lot of air like it would be normally. And then when I lower the speed I get less air blowing. When I was driving this morning and when I didn't get any heat I just turned off the whole heater for the rest of the day. So I will have to check again tomorrow morning again just to be sure.

Thanks for the diagrams of the blower motor (part #8) and its housing, along with the heater core (part #2). Should I be checking these parts for anything?

Edited by dedes
Posted

do u smell any odor of anti freeze inside the cabin? cause leaky heater core can cause this.

also when u check the dip stick ,to see white foamy residue(mixed w/ water) + start the car with coolant resirvore cap open to see there are any bubbles.

Posted (edited)

do u smell any odor of anti freeze inside the cabin? cause leaky heater core can cause this.

also when u check the dip stick ,to see white foamy residue(mixed w/ water) + start the car with coolant resirvore cap open to see there are any bubbles.

[/quote]

While both you and Maurice responded to me, I went to my car to check the oil and heater vents for blowing, etc.

No odor of anti freeze inside of cabin

and checked my dipstick - oil is fine and no white foam residue as you mentioned

Plus, I turned on my car and turned up the heater/blower (which is blowing air at the highest and lowest), warm air started to come out. I cranked up the temp to 76 degrees for a minute or so and warm air came out. Not sure if it is the warmest air because car is not moving. Earlier today that was not the case, I had no warm air. It was coolish air coming out of the vents (no a/c on) I turned the heater off because it was warmer not to have it on. It was a cold morning though.

What's going on? It all sounds a bit peculiar for cool air then hot air. What should I be watching for? I do maintain the car very well. I can inform my mechanic or do I need to maybe do something on my own DIY.

thanks for all your reply's

Edited by dedes
Posted

do u smell any odor of anti freeze inside the cabin? cause leaky heater core can cause this.

also when u check the dip stick ,to see white foamy residue(mixed w/ water) + start the car with coolant resirvore cap open to see there are any bubbles.

[/quote]

While both you and Maurice responded to me, I went to my car to check the oil and heater vents for blowing, etc.

No odor of anti freeze inside of cabin

and checked my dipstick - oil is fine and no white foam residue as you mentioned

Plus, I turned on my car and turned up the heater/blower (which is blowing air at the highest and lowest), warm air started to come out. I cranked up the temp to 76 degrees for a minute or so and warm air came out. Not sure if it is the warmest air because car is not moving. Earlier today that was not the case, I had no warm air. It was coolish air coming out of the vents (no a/c on) I turned the heater off because it was warmer not to have it on. It was a cold morning though.

What's going on? It all sounds a bit peculiar for cool air then hot air. What should I be watching for? I do maintain the car very well. I can inform my mechanic or do I need to maybe do something on my own DIY.

thanks for all your reply's

Dedes:

Since your blower motor is blowing, no need to worry about that part for now. Since you don't have any antifreeze odor (or fumes/coating on the inside of the windshield) then your heater core (which is just a very small radiator) is probably not leaking, so it should be okay too.

From what you have described above, it's possible that you had air somehow trapped in your coolant and, as a result, the heated coolant was not circulating properly throughout the cooling system, and thus not circulating through the heater core. That would explain why the air was not as hot as you are accustomed to getting.

Check the level in your coolant reservoir, and also maybe bleed the system. A good (and easy) way to start is to simply lift the bleeder valve lever, which is located under the thin black plastic cover on top of the reservoir tank. Here is a photo of the bleed valve and lever:

post-6627-1200197312_thumb.jpg

You can see the lever's straight metal portion on the left side of the photo, which is the one opposite the "S-shaped" portion. That's the part you lift up, with the S-shaped part remaining in contact with the top of the plastic assembly.

You can drive around for 30 or 40 minutes with the lever in the up (vertical) position, and then simply flip it back down. Be sure to check your coolant level again after the car has cooled down for a few hours. If you find that the level dropped, you have most likely hit on the solution to your lack of heat problem.

Do not open the coolant fill cap while the engine is hot, you could get scalded. Put a rag over the cap as you are unscrewing it for extra safety. If it's less than a quart or two, you can just top it up with straight distilled water.

Regards, Maurice.

Posted (edited)

Maurice,

This sounds all good and I am familiar with what your saying. Pedro, who you may know on PPBB showed me this procedure at West Coast Boxsterfest last October 2007. Because I had some coolant spill out from the high altitude in Tahoe. The coolant expanded/over flowed by the time I reached my final destination in Tahoe. Probably too much coolant in tank then. So Pedro had me fill up the coolant tank with distilled water and then show me how to purge it to get the air bubbles out. Plus he showed me how to turn off the CEL, because it was lit from the spill.

So probably I had a air bubble in the coolant like you said. That possibly explains the cool air then the hot air. Good job Maurice. But I will still keep my eye on things. I appreciate all your efforts to explain all of this to me. I learned a lot from both you and juniiuc.

Thanks so much for giving me the heads up on this!

Dede

Edited by dedes
Posted

Maurice,

This sounds all good and I am familiar with what your saying. Pedro, who you may know on PPBB showed me this procedure at West Coast Boxsterfest last October 2007. Because I had some coolant spill out from the high altitude in Tahoe. The coolant expanded/over flowed by the time I reached my final destination in Tahoe. Probably too much coolant in tank then. So Pedro had me fill up the coolant tank with distilled water and then show me how to purge it to get the air bubbles out. Plus he showed me how to turn off the CEL, because it was lit from the spill.

So probably I had a air bubble in the coolant like you said. That possibly explains the cool air then the hot air. Good job Maurice. But I will still keep my eye on things. I appreciate all your efforts to explain all of this to me. I learned a lot from both you and juniiuc.

Thanks so much for giving me the heads up on this!

Dede

Dede:

Pedro has an excellent procedure for bleeding the coolant system after a flush/refill, and he certainly is very knowledgeable, as well as being the king of hacks.

Be sure to let us know how you resolve the problem.

Regards, Maurice.

Posted

Thanks Maurice

I will have to email the "King of all Hacks". And tell him what happened here. Great guy!

I will let you know.

Dede

Posted (edited)

Do you have air con, and is this manual or automatic?

This problem could really be something so simple as a flap not working.

Cant believe the comment about head gasket- why do some people always look for the most serious problem

Edited by Glyn
Posted (edited)

Wow what u said was strictly referring to me, I guess

what can't you believe about my comment about head gasket? "why do some people always look for the most serious problem"- I'll take that as why does JUNIINC? LOL It's not that I always look for the serious problem, but I do try to find every possible cause.

what? you don't think 986's gasket can ever go out or cold air should be blowing when the gasket is blown?

Maybe I just didn't realize that it was a major crime to be checking something simple <_< .

I really wasn't stating that the gasket was blown,just hoping to see it wasn't ,,,as a matter of fact that I've seen a couple cases in the past.

Perhaps if u ever see it happen, U might be able to believe it,,,

hey dedes, like Glyn said it might be something simple such as Inside temp-Sensor mounted in the aspirator assembly at the side of the dash/Temperature mix Flap command/Temperature mix Flap position,,,let's do this-

There is a HIDDEN 986 AC DIAGNOSCTICS you can perform simply. since your car is 98 this should work.

The AC Climatronic unit is actually manufactured by Audi. There is some sort of serial data stream (not CAN) that allows the AC unit to display engine parameters. This works on 1997-2000 boxsters.

To access diagnostics:

Hold down the Recirculating & Air up buttons for 5 seconds. The + - buttons go up and down through the list of "c" codes. The center vent button switches the left display between the "c" code and its actual value. Press the Auto button to exit.

Do you have air con, and is this manual or automatic?

This problem could really be something so simple as a flap not working.

Cant believe the comment about head gasket-

Edited by juniinc
Posted (edited)

Wow! Quit quoting every email from the previous email, not sure why people do that on this list so much!!

I believe the head gasket talk is a stretch too, or at least to early in the trouble shoot process. You would see some heat unless there was a huge loss of blow by from coolant to oil side. But it is easy to check the oil level and if there is coolant in the oil or oil in the coolant to ease such concerns.

1. check you have sufficient coolant level. Most likely you do but if it's to low I've seen some cars not be able to get heat because the coolant level is to low to transport the heat. Doubt that is the issue in this case as you low fluid level light would most likely be on. This has happened on the wife Saab 9000. Enough fluid to cool the car but not enough in the heater core.

2. I though the Audi diagnostic was an old wives tale because the units are similar but he could be correct. It doesn't work on my 98 so it may not work on yours. FYI durametric software now has the ability to tell you open/close % of all air system flaps. I would suspect the primary heat flap. If you can diagnosis this and don't have the $$ for a Porsche tech get the durametric software. It is you first place to start with servo failure and sensor temps.

3. If you get in the passengers footwell and look up behind the center console with a flashlight you will see the servo and arm that adjusts the primary flap from the cool to hot air side. As you take your temp buttons from low to high again you need to see that survo moving. Additionally check the arm that controls the flap is in fact ont he servo or has not broken.

See my write up for details on a procedure I had to do which involves the servo in question:

http://www.carboncow.com/pages/porsche/heater_door.htm

I've included a nifty screenshot of the durametric softwares HVAC system diagnositcs. YOu can pick up to 8 parameters to show realtime values. As you can see the mixing flap is at 100% and should move from 0-100% as you change the temp, but again you can see this from down below w/o spending the $$$. But no Porsche owner that is a DIY should be w/o this software!

post-13335-1200231950_thumb.jpg

Edited by rsfeller
Posted

In answer to your question Glyn:

Do you have air con, and is this manual or automatic?

Yes, I have the air conditioning feature on my car.

My car is manual.

thanks

dede

Posted (edited)

Hey juniinc, your comment:

"It's not that I always look for the serious problem, but I do try to find every possible cause."

I appreciate your input, because I like to know every possible reason or cause. Sometimes it is hard to read or understand what is actually going on with a car. I am so happy to have yours and everyone's answer. :) It is very cool that everyone is trouble shooting this problem. And myself and everyone else can benefit from it.

Now getting back to reading more of yours and everyone's information. Once I have some coffee and absorb all this feedback, I will check out my car today. For oil, coolant, flaps, a/c switches, cool/hot air vents and etc etc etc. Whew, you got me working. :renntech:

thanks

dede

Edited by dedes
Posted (edited)

Hello rsfeller ,

your comment:

"Wow! Quit quoting every email from the previous email, not sure why people do that on this list so much!!"

thanks for bringing that up! It does get very hard to read posts/threads that way.

So I went back and edited a few of my posts, sure is a lot easier to read. (just for you) thanks :)

Wow, thanks for your complete write up for details on a procedure which involves the servo in question.

I did a search and I did find your write up earlier. Now I am talking to the guy who wrote it. How cool is that! :clapping:

Ok, I will check the flap underneath the dashboard, behind center console. And re-visit the coolant tank. I will get the car warm before checking for a accurate reading of fluid levels.

I have been looking into the the durametric software. It's handy to have it for DIY diagnostics, etc.

thanks

dede

:renntech:

Edited by dedes
Posted (edited)
Thanks Maurice

I will have to email the "King of all Hacks". And tell him what happened here. Great guy!

I will let you know.

Dede

My email response from Pedro, if your interested.

On Jan 13, 2008 7:22 AM, Pedro Bonilla ......... wrote:

Hi Dede:Good to hear from you.

Thanks for all the accolades!

So, did the air purge solve your problem, or are you still not getting heating?

I also believe that whenever you have a problem it's best to look for the simplest solution first.

To make it simple, inside the dash, right before the blower fan there is a small radiator which has a valve that allows hot coolant to circulate while the blower flows air through it and thus heats it, and sends it to the vents via ducts.

There is also a set of coils (from the A/C) that when the A/C is on will do the same, but in reverse.

The blower also draws air from two different sources. It can draw fresh air from the outside (through the air filter next to the battery) or it can draw air from the cabin (recirculation) cutting off air from the outside. The intake to this blower is controlled by a flap which opens or closes depending on the setting on the control unit.

So, your problem could be one of various:

a) A bubble of air in the system, in particular in the heater core (small radiator in front of the blower fan).

B) A sticking valve that won't allow the hot coolant through the heater core

c) A sticking flap that's allowing cold, outside air in and not letting the heater core heat up enough.

Of all of them I would start with "b".

As it was stated, our cars use an Audi A/C control unit which allows us to see many features and positions of the system. You can find it here: http://mike.focke.googlepages.com/un...dacdiagnostics

Let me know if you need more info/assistance.

Say hi to Kevin for me.

Take care.

Happy Boxstering,

Pedro

__________________

Edited by dedes
  • Admin
Posted

Try this...

Put you hand on the heater core after the engine is warmed up and at operating temperature. The heater core is in the center under the front hood near the battery (follow the two hoses).

It should feel warm. If it does then the problem is the the heater controls under the dash or a bad air flow temp sensor.

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