stuart1997

One thing i have never noticed ;is the engine blower fan staying on after i switch the engine off.
Saying that when driving my car normally shortish journeys 50 miles or so the temp guage never seems to go past the first white marker.
The heating and ventilation seem to work fine.
Is this a cause for concern ? or is it that the engine is just not getting hot enought to warrant the fan staying on?
cheers stu

jimq

Mine never comes on or stays on when the key is off and it gets real hot here in the summer.

Dunasso

Does the blower cool the engine, blowing cooler air through the exchangers? Does this cool the exhaust after the engine is off.

I ask because every once in a while mine use to come on when the engine was turned off. I have since removed it.....should I put it back on?

Duncan

stuart1997

Im asking this after reading the scary "Fire in the hold thread"started my Tinwan

Euromagination

Mine never has stayed on either. Get that checked out!

dfinnegan

Mine has come on. I was playing around with the Hammer in the drive and let it idle for quite a while. Managed to get the temp up to about the 9 o'clock position in order to test some inputs. After shutting down I was surprised a short while later when the fan kicked on. That was the only time, but I was pleased that it did work.

jimq

It is suppose to come on if it gets to a certain temp after it has been turned off. Mine just hasnt reached that magic number at least while I could hear it running.

Euromagination

Hmm... Mine has never come on. At least now I know that if it does, it's okay.

stuart1997

Yeah mine never comes on -just re-read my initial post (my grammar sucks)

JasonAndreas

From the dealer mechanic training manuals (not the workshop manuals), "Ballast resistor (R) is located in an air guide on the pressure end of the rear heater blower. The ballast resistor holder is engaged in an opening of the air guide. A NTC temperature sensor (T) is located in the same air guide. The temperature sensor can be removed by turning it 90'. Temperature sensor (T) switches on the rear heater blower independent of the above mentioned blower switch positions:

At approx. 45 ... 75'C in basic stage (9 V)
< 40'C basic stage off
> 75'C to max speed stage
< 70'C max. speed stage off

If the ignition was turned on for at least 30 seconds, temperature sensor (T) activates pertinent after running of the heater blower which could be max 15 minutes long on a stopped car (ignition off). Electronics of heater/air conditioner controls monitor temperature signals up to 15 minutes after the switching-off of blower after-running or after turning off the ignition. Heater blower after-running with temperature > 95'C and ignition turned off.
After-running switched off at approx. 93'C"

Dunasso

Jason,

That was some very good info, I think that we all learned something new.
What you're saying is, the fan is suppose to come on while the car is off, and can possibly run for upwards of fifteen minutes.

Now for the million dollar question........is it hurting my ride to NOT have that blower in place? I removed it because it was making noise.

Duncan

stuart1997

I guess my engine has never got to 95`c when ive come to switch if off,and with type of car the 911 is (noisy) you wouldnt hear it going with the car in motion.

DarrylH

The blower will run during heat soak only rarely, with a combination of high ambient temps and high engine temp at shutoff being required to start it up (maybe a hot North Carolina summer day, but maybe not even then?) It will run much more often with the engine off but the key on; the temp threshold is much lower - see Jason's post. That's why if you park the car on a hot day for a short time, come back, and turn on the key, the rear blower will often start up on low speed. It's gotta be really hot in the engine compartment for the blower to switch to high speed...maybe the guys from the tropics can chime in. Another factor is that the blower usually starts up about 5 minutes after shutdown, because the heat in the tubes increases for a while. If you don't hang around the car, you'll never know it ran!

I seem to remember that the Cup cars had no blowers, can someone confirm this? If true, it seems likely you're fine, although maybe the Cup owners were expected to cool the engine bay manually (fans, etc) when the cars were very hot?

robbed666

Mine stays on sometimes, but that due to a sticky relay in engine compartment control box.
I just give it a smack and it stops! I cant get in the box to change the relay at present, due to cover securing nuts are so coroded they wont undo!

tabasco

Mine used to stay on when I bought the car. Even if I started the car for just a few seconds, cold engine, the fan would run for 10/15 mn after that.
No need to tell the battery did not like it.

Went to the dealer, they changed something (thermostat ?) and I don't remember earing that fan again since then.

-Guillaume