Lvt19672

Does anyone really know what an unsafe oil temp range is?, ie when should you shut it down? Is there a warning indicator on the oil temp gauge?

Hella-Buggin'

I don't necessarily worry about the oil temp by itself but factor in the increased g force and RPM's with a car with 65k miles on it and wanting to get many more and at what point does it make sense to consider.

I don't know that the third radiator helps in traffic as it doesn't have a fan so it needs air rushing over it to cool.

tgavem

Oil facts: Over 300F the oil will start foaming, but the oil can absorb oxygen and start foaming below those temperatures when older. Most motor oils have additives and are tested (NEW) to verify the temperature where the foaming may start. Back to basic questions; adding a 3rd radiator will help reduce engine temp and with frequent oil changes (every 3-4 track weekends) is the best way to increse engine longivity. Why the Turbos, GT3 etc have the 3rd radiator.

slicky rick

3rd rad should also help in traffic as it increase the area where heat is dissipated. Does not have to have a fan it still radiates heat out of the system. For me, whether the car really needs it or not now is irrelevant. What is important is if it bothers you and your asking then at $250 its already worthit. Peace of mind is priceless.

RichFL

$250? $900 for my 997.2.

dasams

The reason it's standard on PDK is because of the heat generated by the transmission.

In the 997's, the oil cooler is submerged in the antifreeze so that the heat is dissipated through the radiators (on a cold start-up, the antifreeze helps warm up the oil). For a 6 sp car, there's no fluid and hence no additional heat to pass to the radiator. But on PDK, the tranny fluid cooler is also submerged in the antifreeze which increases the load on the radiator. Somewhere post the 2009 model, Porsche must have decided that despite the cost, a third radiator was justified as standard equipment.

user 72902

Just an interesting observation on my car - when I added the lower temperature thermostat my oil temps have consistently stayed at about 212 degrees even in 100+ temps. If stuck in traffic it will climb to 225 and there is no need to turn off the AC. Later on I added the third radiator and have not seen any difference in oil temp readings during this past summer. I don't really pay too much attention to H2O temps; I'm more focused on oil temps.

Hella-Buggin'

I think the PDK cars required the third radiator because the cars driven harder in sport plus mode were constantly in the higher rpm ranges and this created more heat.

Asquared

I hope you are not relying on the idiot gauge in the dash to conclude that the water temp is staying at 175, for reasons not completely clear to me, that gauge does not move with water temp inside the operating band (it will tell if it is not warm yet and it will tell you if it is too hot, but in between, the needle doesn't move). There are a number of threads here that discuss this.

I bought a gopoint OBDII reader that connects via BlueTooth to my iPhone and gives you an accurate water temp reading. I keep an eye on the real water temp when my oil is getting warm. It can vary, but generally, when moving my water temp is around 20 degrees less than the oil temp. On the highway at speed, my water temp is hovers around the high 190s and the oil is around the mid teens. When stuck in traffic, the water temp climbs with the oil temp, and the gap can shrink, although I don't think I've seen the water temp climb above 225 since I've had the reader.

During one stop and go session, the water temp climbed from 160 to 215 and the temperature gauge on the dash didn't move a lick. Once the water temp gets above 220 or so, the gauge will move off the center but never come close to the OBDII reading.

Edgy01

Asquared---thanks for adding the real-world numbers because PAG chose to dumb down the water temp gauges for modern day Porsche drivers. When they added water (EGW) as a coolant in 1999 owners quickly called to inquire about what they perceived as high numbers. Porsche engineering chose to dumb down the read outs to minimize concerns that they were damaging their engines. You will find that engine water temps sit at "175º" forever--until you are truly in trouble! By the time it gives an accurate readout of that higher temp you better be prepared to shut it down.

Many years ago when I drove air-cooled 911s, I experienced oil temperatures in Oklahoma of up to 350º -- but for brief periods. That was just in normal driving! I can assure you that those numbers will shorten the life of an engine. My next 911 had a massive Behr cooler in the front right fender and that resolved my oil temperatures in the same part of the country immediately. The liquid cooled cars benefit from both excellent liquid radiators and oil radiators. There are actually reasons not to add an additional cooling capability--believe it or not! If you add additional cooling the thermostat will have to keep the coolant from those radiators longer until the engine gets up to operating temperature. You really don't want an engine to run too cool, either, as it affects engine performance as well as fuel economy.

As you have learned above in this thread, Porsche introduced the PDK tranny only to discover that it generated additional heat which could only be resolved with the inclusion of the third, center, radiator. Just like those who want to take the rear bumperettes off the rear of their rear bumpers, there are cost issues for having some things, and not having things. Keep in mind that the inclusion of a third central radiator now adds stone-damage potential to your car--you're essentially doubling the exposure from what the stock configuration provides. For those who have taken a hit from a small stone in their radiators they will probably tell you to either skip the extra radiator or ensure that it is fully protected with mesh. As with others, I naturally thought that it would be nice to have the added 'benefit' of a third radiator but being that I live 3 miles from the Pacific Ocean, I find it difficult to justify--my ambient temps are so mild.

dasams

Are you getting your oil temps from the gauge? If so, how do you know it isn't also dumbed down?

Arctic Wolf

A manual car and a PDK car can equally be driven in higher rpm ranges or low rpm ranges, it all depends on how you drive it.

Perk10

I got the third radiator with my X51 powerkit. Never asked questions. It keeps me cool at ALL times at stop and go traffic or driving hard. I live in 100 degree heat sometimes with 100 percent humidity. That's about all I know

Psymon

Just for information.... I'm in Hong Kong, my 06 C2S has the 3rd radiator, and I'm pretty sure it's a standard equipment here as I see it on pretty much all C2S (non sure about non-S).

And Hong Kong is purely city traffic!

Cheers.

USMC_DS1

The oil temp on my '08 C2S MT used to get as high as 270+*F during the worst of summer heat on my canyon runs here in TX . After the 3rd rad, FVD ext oil pan, and switch to Motul X-cess... the temps have dropped to 235-240*F during those same canyon runs. Very pleased with the 3rd rad.