i'm gonna go ahead and get a NEW bigger S oil cooler as a start (thanks flaps10 for the tip!)

found one on pelican made by BEHR for $168.50 and the Porsche OEM one for $342.50.

part number 996-107-025-59.

a few questions before i go ahead and buy it:
this will fit my 2000 2.7 right?
any reason why i should spend more on the Porsche one? price difference is considerable.
what else should i be buying with it? i see two different sets of O rings (4 in total). is that right?
anything else?

thanks!

We have never used anything but the factory part (996-107-025-59), so I cannot speak for the other unit. The factory unit usually retails for about $260.

It will fit your 2.7.

There are four O-rings in two different sizes, and they should never be reused.

ScanGauge ?
 

Possible cooling problem & suspect calibration of the dashboard instruments.
Has anyone had success using a Scangauge or Ultragauge as a way of verifying the accuracy of the dash instruments? Yes, I know theses aftermarket gauges just read the same sensors that the OEM dash gauges read but perhaps they are more accurate.
I ask because some Forum members have spent much $$ and time chasing non-existent coolant temperature issues.

what about connecting the OBD2 tool which will read the exact engine data to rule out any gauge fault?

I use the app Dash Command pretty often to see what's going on with water temps and a few other things. For both my 986 and 996, the line at 180 is 180 degrees; straight up is around 200, and the right edge of the "0" is 220. I'll get the right edge/220 on a hot day in traffic, and as soon as I'm moving 35+ for a bit, the temp drops back down to 190-200.
Both cars have the 160 T-stat, new water pumps, and the larger water/oil cooler. 986 has a center radiator, 996 does not.

thanks a lot for these details they really help paint the picture and put my mind at ease as i'm getting the same temperatures (and sounds like your setup is even better than mine for the 986, i'm all stock with no center radiator) so its not out of the ordinary. i was about to drop quite a bit of money into it to try and sort it but i think i'll let it be until the next coolant change when i will upgrade to a better water pump.

still thinking about upgrading to a bigger oil cooler as that is a cheap easy improvement.

I don't think you understand the function of the thermostat. It opens at its set point to allow the flow of coolant, but it has no control over what temperature beyond that the coolant might eventually reach.

Fwiw
 

Mine runs at just past 180, all the time I though this was normal.......it never runs hot in the very hot Alabama sun here.

Which OBD BT are you using for the Boxster?

ELM 327. I got it on Amazon under $30. Wifi, not BT.

I noticed that Pelican & L&N sell an instal tool for the low temp thermostat. Do I really need that? Previous (non porsche) cars, I've just dropped the new thermostat in. Thanks in advance

You have a couple of options. You can buy a thermostat already in a housing. This is a bolt-on and doesn't require the tool. Or, you can just buy a thermostat and re-use the existing housing. The tool makes it easier to install the new thermo in the old housing, but isn't absolutely necessary - you can do it without the tool.

I use this one ELM327 OBD II Wifi CAR Wireless Scanner Tool Diagnostic FOR Iphone Ipad Android | eBay

I use it with an iPad App 'DashCommand' It works well, and my temp readings are pretty much the same as others' here. Just had the WaterPump changed and the cooling system flushed amongst other things.
Driving around winding and hilly country the other day in some heavy traffic I guess the temp reached maybe 220F around 100C. Going up hills behind slow cars is murder as couldn't really get it out of 3rd in a TIP.

These 986s seem to have this heating issue, but reading through this I may just change Air Temperature Sensor for Intake Manifold. Pretty sure the fans kick in, but still I'll change the sensor just to see if it makes any difference. At the moment no CEL lights come on, so I don't know if any real issue exists.

thanks for the info! i got the same OBD II device now and using it with DashCommand its pretty cool and useful! :)

i went ahead and changed the engine bay temp sensor but didnt do anything. did quite a bit of research and it sounds like the only thing that will really help is an upgraded water pump from the 987 and a bigger oil cooler.