993 heating issue...what can it be?

[TVP993]

Hi All,

I have a couple of issues with the heater. This is all quite recent.

1, Does not blow hot air even when the temp slide is turned up fully
2, When I turn the fan speed (blower) up it doesn't always come on. Then all of a sudden it comes on on it's own.

Could it just be a dodgy connection or something else more expensive.

Then whilst driving a few weeks ago I noticed that the oil temp gauge was right up past the redline. I had only been out for 20 minutes so started freaking out thinking the engine was going to blow up. However I decided to keep an eye on it and literally 5 minutes later in one fell swoop the needle jumped down to the middle.

Engine oil level and pressure are both fine. Is this something to be worried about or is it another 993 quirk?


Any feedback appreciated.

Cheers

[BrakeFade]

I get the same problem with the temperature gauge on my 993. It just goes up to the max sometimes and then I have to tap it lightly to get it back again (or I don’t bother anymore). I think I have read somewhere that it's quite common.

It does scare the crap out of you the first time it happens though.

[Pickled Piper]

I have no idea but if you post on 911UK you can seek out a member called ToreB. He's a Norwegian chap that has an alarming and anorakal level of knowledge on the workings of the 964 and 993 heating system.

pp

[TVP993]

Thanks PP. Done.

Pickled Piper said:

I have no idea but if you post on 911UK you can seek out a member called ToreB. He's a Norwegian chap that has an alarming and anorakal level of knowledge on the workings of the 964 and 993 heating system.

pp

[lynchygt3]

have you checked for a water leak

[TVP993]

Definitely no leaks at all.

lynchygt3 said:

have you checked for a water leak

[james964]

Hi

Had a similar problem with the heater in my 964 turned out to be the fuse controlling the rear blower. If air is not blown from the rear the heater will cut off.

[james964]

Hi

Had a similar problem with the heater in my 964 turned out to be the fuse controlling the rear blower. If air is not blown from the rear the heater will cut off.

[speed yellow 911]

lynchygt3 said:

have you checked for a water leak

you are joking I take it?

[shax40]

Hi All
I have a 993 and am a new owner of this so all the problems I have faced have cost me a fortunes so far and i'm now trying to diagnose issues before I get ripped off!
My heater blower is not working! I can not seem to hear it blow and I am not getting any heat from anywhere even after giving the car a good run, I have checked the fan fuses which all seem ok just wanted to ask if there is anything else I should try look for
thanks

[996Type]

Hi,

There are various potential causes, some relate to the unit in the dash itself and it’s various sensors ( I had an issue with a vacuum leak for example as the cause of none operational air conditioning which was a 2 minute fix).

Head over to 911UK forum and search the 993 section as this will have been done several times before and allow you to get a more accurate view on what could be wrong.

[PTT]

https://www.bergvillfx.com/porschehvac1

lot of problems and the solutions

[gwsinc]

shax40 said:

Hi All
I have a 993 and am a new owner of this so all the problems I have faced have cost me a fortunes so far and i'm now trying to diagnose issues before I get ripped off!
My heater blower is not working! I can not seem to hear it blow and I am not getting any heat from anywhere even after giving the car a good run, I have checked the fan fuses which all seem ok just wanted to ask if there is anything else I should try look for
thanks

Lots of good info at the website in the previous posts.

If you’ve checked all the fuses (and relays) in the front make sure you also check the fuses and relays in the rear fuse box by the engine. If it were me, I’d unplug the fan and apply 12 volts to see if it works, if it does you can be sure it’s something else!

Good luck!

[stevewak]

PTT said:

https://www.bergvillfx.com/porschehvac1

lot of problems and the solutions

Exactly. And get over to the 993 forum on 911uk. The 993 heating/cooling system is a world of pain but every problem and fix is online.

[BillyB]

I’ve spent a fortune getting various bits and prices associated with the hot air system fixed on my 964. I don’t even pretend to remember them all. It ain’t a simple system. Unless you are handy with electrics and spanner’s, my suggestion is live with it or take it to a specialist you trust and open your wallet.