Is it normal for the temp guage to fluctuate so much? I saw the needle hit that first mark after the 180 and have never seen it stay in the "middle" since I've had it, 25k miles MY00. I tried searching the archives but didnt find anything. I called the dealer and was told this was normal. Just need some reassurance if in fact this is normal. Also, does Anybody have intructions on installing the third radiator? Thanks

 

Try 'Lorens' Site at the following address...

This site has some cool DIY projects including the 3rd radiator install with pics etc. It looks reasonably easy to do.

http://www.garlic.com/~ljcook/indexDIY.html

Can't help with your temp issue though, as my Porsche ain't here from Germany as yet....

No doubt someone will post a reply to your question regarding running temperature....!

Costas

 

The problem really isn't hitting that first mark it is what happens when you turn the car off (and the temp goes up another 20 degrees). A cool down is highly recommended 2-5 minutes -- the 3rd radiator will help a little with that simply with the slightly increased capacity. The big help of the 3rd radiator is track events, mountain and twisties roads where you will rarely see it go over the 180 mark.
I live in NorCal and I think it is a must option here.

 

When you say cool down, are you talking about letting it idle for a few minutes? I do that after each run session at the track so it doesn't heat soak.

 

Scott - 'You're On the ball'

This is exactly what Loren is referring to. As a matter of fact, somewhere in the handbook it actually mentions that after prolonged aggressive driving you should not switch off the engine right away, but let it idle for a few minutes.

This has 2 main benifits:

1: Engine coolent is still pumped through your engine and radiators while it is running thereby cooling your motor efectively.

2: If the radiator fans are running (which they probably will be doing after running the car hard), having the car idle will still allow the alternator to keep your car battery charged. If you kill the engine the fans will draw power direct from the battery and this is not the most effective way to run them. (you will find that the fans draw quite a bit of juice 10 to 20 Amps worth).

Costas

Soon to be 996 owner from Down-Under

 

Scott, that's what the cool down lap is for you leadfoot

FWIW, the third radiator does help quite a bit at the track, temp now never goes past 8-0 in 180 ( about a 10-15 deg drop for me), all in all a good upgrade in a Texas car with track use. Otherwise, not really necessary on a pure street car IMO. It is a fairly straight forward upgrade though I wouldn't say it's an easy DIY, definitely not for the faint of heart DIYers IMO. But it is worth the trouble, as I bet the dealer would charge a grand for labor based on what is involved.
Another mod I'm thinking of adding is a Tiptronic waterpump. The tip pump will flow 15,000L vs 14,000L , providing a higher flow for the third radiator.

 

DJ996...

The Tip waterpump retrofit sounds like an excellent idea...

I'd probably bet (not too much) that changing your pump out for a higher flow rate unit will be way more effective than adding the 3rd radiator. (If you do both mods thats better again)

I say this from my experience in water cooling PC's. My current PC is watercooled (+ overclocked etc etc) and the most effective way of keeping the temp down is by increasing the flow rate.

Providing the radiator('s) surface area can cope, there is probably no real major gains in increasing them....BUT if you increase the flow rate you effectively increase the ability to remove heat from the surface you are trying to cool (Engine, PC-CPU etc).

Normally in a PC we can easily increase the diamater of the water hoses and also increase the pumping capacity by buying a bigger pump!

Costas

 

Water cooled PC?

You know... the only real PCs are air cooled. LOL


Seriously, what kind of PC are you running!?

 

You lost me there... where did you get your information? (I mean this in a polite way)
According to the parts list there is only one water pump for all Carrera's. That includes both 3.4 and 3.6, 6 speed or Tiptronic. There was a part number change (from 996 106 011 51 to 996 106 011 53) but there is no other difference.

 

My reference: Frere P: Engine developments 1998-2001. The Porsche 911 Story, 7th Ed., 373, 2002.
"The single water pump circulates coolant through the engine and through two radiators each located in front of the front wheels, although cars fitted with Tiptronic S transmission have three radiators. The pump circulates coolant at a rate of 14,000 litres (15,000 litres in the case of Tiptronic S cars) per hour and runs at 1.21 times crankshaft speed"
Makes sense to me that there would be a higher flow pump for cars with an additional radiator.

 

Scott,

My PC is an Intel P4 based system (2.6 GHz CPU) running at 3.4GHz Overclocked + Water cooled.

Running 2 radiators (1 Internal + 1 External) and a few fans + a 600 litre/hr fishtank pump. The fans are 24v units running at 12v - This allows the system to run very quietly!

Most overclocking requires a lot of extra cooling and the easiest way of accomplishing this is by adding a larger heatsink on your cpu + high speed fans.
High speed fans = High noise which I dislike.

Watercooling is slowly becoming more mainstream and you can actually purchase complete kits.

The whole idea of overclocking is basically to push the system to its limits with the available hardware...A bit like modding your Porsche with superchargers etc.... Just a whole lot cheaper!

Here is a messy pic of insides.....

 

Here is a closer look at the Business end....The black CPU block (machined out of Aluminium + Copper) which clamps over the CPU and has water circulating through it.

Costas

 

hehe cool.

I'm just disappointed that my 993/996 reference went unnoticed. I was proud of that joke. hehe