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Hi all! It's cool here in the Pacific Northwest and I'm having issues with poor interior heat. Have a 2014 4S with 4-zone climate control. Last few weeks luke warm air is coming out the vents even though I have the heat cranked up. Coolant temperature and oil temperature show the car is good and hot but getting very little heat inside the cabin. Thank goodness for heated seats and heated steering wheel otherwise I'd be in ice cube. Anyone else had this problem? I'm taking it in to my independent Porsche shop on Friday but hoping to have some thoughts on what might be the problem. I've read on the 911 forums (997 and 991) that they have issues with the "change over valve and solenoid". Not sure if this also applies to the PTT? Ideas? Thanks in advance.
Question on symptoms:
Is the lack of heat the same a idle / very low rpm as it is a highway speeds?
(looking to see if water circulation is the problem)
Is separate 12V pump is used to provide coolant flow to the HVAC heat exchanger when the car is in REST heating mode? This is a separate pump from the engine coolant water pump which is belt driven. Not sure if the Panamera has this pump -- my older MB with REST mode heating did. When that secondary pump failed - heating was marginal at best. I would assume there would have to be some type of electric pump for the REST mode to provide heating while the engine is off in our Panamera's. Don't see it in a quick look in the service manual -- but it may be buried deep.
I have had cars with coolant air bubbles issues, be super cold even when driving on highway. Wonder if this car had coolant added/changed recently. Could be a cause. Pulling all codes from the car may yield some new insight here. Thats where durametric can come in useful or other diag tools.
did you set the air flow strength? soft normal strong. it is under car -> option. How is your rear mode? I have 4-zone air conditioning as well. mine is working great, we have cold air from canada to the bay area this month. 47 day time.
So I did a little investigation this morning as it's REALLY cold here now, as I was driving to work I thought about this threat and checked my heater and found out, it too was blowing mediocre air (slightly warm but not much). I check and the water temp was at full (90) but the Oil temp was still just at the first mark. My assumption at this point as the heating is not only reliant on the coolant temp but also on the the Oil temp, perhaps it's busy trying to heat up the block before the passengers. I know this is not how it is supposed to work but it seems very strange.
Now of course this is speculation at this point but may car is usually very warm inside once at full operating temp. I will check more later today and see if once the oil temp gets warmer if the inside temp gets warmer too.
It is strange. Perhaps, you need to check it with your local porsche dealer if your car is still under warranty. I had my Pan4 in Sierra Tahoe few weeks ago, 27f, the hearter was working beautifully after 10 min driving. I hit the defrost, and rear heater i could feel the hot air coming out full blast.
How's your defrosting windshield working?
OK more testing, I found even when close to fully warming with the car in Automatic climate mode just slightly warm air coming through the center vents, but hot at the windshield. I switches off automatic and put it on the center vents and it was nicely hot. Not sure if this is the same as your issue, or if you got to the root of yours, but I am still learning the "nuances" of the PTT
Sorry for the delayed reply. Thanks to everyone who chimed in.
Here's the info to the questions posed:
1. Mediocre heat in all 4 zones (2 front, 2 rear).
2. Mediocre cabin heat even when coolant and oil temperatures at max.
3. A/C off, auto off.
4. Rear defroster working fine.
5. No recent coolant service. Recent oil change (I change at 7500km intervals as opposed to Porsche recommended 15000km intervals). Coolant level appears appropriate.
6. I did not go into menu to adjust airflow levels (I set all this when I 1st got the car and have not changed it since. I used to have great heat and now mediocre so something has changed).
Okay, so here’s my update...
Also noticed that the Homelink button on the roof panel stopped working (press button to open the garage door and the middle “II” button light just flashes but garage door doesn’t raise). This is the 2nd time this has occurred in my ownership. The 1st time I brought the issue to the attention of my local Porsche dealership. They said that they have seen this issue happen if all the seat position memory buttons (drivers and passenger sides) are not programmed (WTF?!). Seemed fishy to me but took their word on it. They programmed all the seat memory buttons and I reprogrammed the Homelink button and all worked fine...until now. This time I do the same process and Homelink works again and now I have interior heat! Crazy! Not sure how it is all connected? Battery is good...I plug it into a Porsche Charge-O-Mat Pro almost every night since car was almost new. Seems like an electrical gremlin...
Anyways, car now at my Indy shop for diagnostic work...they tell me the whole seat and Homelink button thing seems fishy too. Solid independent Porsche shop so trust them to dig into the issue and not just brush me off. Car is covered by extended warranty so hope they find the problem. Will post more when I find out. Thanks again for everyone's thoughts.
Last edited by vkb123; 02-10-2019 at 01:31 PM.
Reason: typo
Just heard back from my Porsche indy shop. Pulled fault code and issue is “heater control valve”. Did quick search and 2 other posts on 6Speed about this part. They are putting the claim through my extended warranty. Will have car back at end of week and will confirm issue resolved. Will post again later once confirm issue fixed.
Confirmed issue was the heater control valve. Replaced under extended warranty by indy Porsche shop. Toasty warm once again! Hope this helps other who might experience the same symptoms.
02-04-2019, 09:50 PM
