Help, Boxster getting hot!

[truegearhead]

I'll preface this by saying that with the heat index its been 115 here during the day which certainly doesn't help. That aside the car has been heating up beyond half way and even threw the warning light yesterday while sitting in traffic. It will heat up on the highway as well at 70 miles per hour. Both fans are on in fact the car sounds like an airplane trying to take off when its sitting still, the coolant level is great, and it doesn't look like there are too many leaves stuck under the bumper in front of radiators but there is a bit in the back corners. Any ideas what I should be looking for? Could it be as simple as a thermostat, or a coolant flush? I'm driving 400 miles to the Porsches to Oxford car show next week so I need to get this sorted.

Cheers

[JFP in PA]

• Clean out the front radiators, you may be amazed at what you find in there.
  
  Install the LN 160 stat, it will lower the "steady state" operating temp of the car.
  
  If the car is a base model, install the "S" oil cooler, best $200 you will ever spend on the car.

[Overdrive]

Well if your radiators are clean and clear and fans are running, the only other thing that comes to mind for me is to see if maybe there's some sort of blockage in the passenger side air intake...?

Is your needle really cranking over to the right? You said the warning light came on, was the temp gauge headed toward the 250?

[truegearhead]

No it wasn't very far at all. It wasn't even to the line in between 200 and 250.

[jaykay]

I was doing a little driving on some tight lower speed turns at 4 to 5K rpm and the temp crept up to past the 0 in the 80 C (180 F for you southern folks). I havent seen that before under similar driving conditions. It is has been close to 100 F here in Toronto recently. It took a long highway drive to dissipate the heat. I get the feeling that the ultimate cooling capacity of the car is not what it should be even with the hot weather

[mikefocke]

I'd have guessed that if you get the "water" temp down it would help cool the oil down.

[tonycarreon]

Originally Posted by truegearhead

I'll preface this by saying that with the heat index its been 115 here during the day

heat index won't affect the car. just like wind chill won't affect it.

Originally Posted by truegearhead

That aside the car has been heating up beyond half way and even threw the warning light yesterday while sitting in traffic. It will heat up on the highway as well at 70 miles per hour. Both fans are on in fact the car sounds like an airplane trying to take off when its sitting still, the coolant level is great, and it doesn't look like there are too many leaves stuck under the bumper in front of radiators but there is a bit in the back corners. Any ideas what I should be looking for? Could it be as simple as a thermostat, or a coolant flush? I'm driving 400 miles to the Porsches to Oxford car show next week so I need to get this sorted.

was the roof open or closed? anecdotal evidence has shown (for me at least) that when the roof is open (retracted) the car runs hotter when stuck in traffic. additionally, running the A/C seems to help a little.

the warning light has two "displays." a steady light indicates the temperature is too high, a flashing light indicates the coolant level is too low.

i would think if the thermostat was not working, it would heat up rapidly and consistently, not just when stuck in traffic. that said, it would be one of the first things i investigated after making sure the coolant level was correct and after cleaning the radiators.

[JFP in PA]

Adding a third radiator will boost the car’s overall cooling capacity, but at considerable expense and work as you will need to color match a new bumper, add the third radiator system kit, etc. Moving the car to a larger oil cooler will actually aid in lowering the car’s operational temps by accelerating removing retained heat from the oil before they have a chance to build up. Swapping out the cooler is a simple, and much cheaper, move (four bolts and new o-rings and you are in business), which when combined with a switch to the lower temp stat, for which you need to drain the cooling system anyway, typically goes a long way in improving the car’s overall running temps. We have had several customer’s note how much cooler the car stays, even on track days, after doing this; plus the UoA’s show the oil was happier as well. For reference purposes, data collection on base cars running the larger cooler, the 160 stat, and the third radiator, versus base cars with only the stat and cooler showed that the addition of the third radiator slowed down the rate of temp rise as well as cooled off more quickly than base cars without the extra radiator, but both eventually return to very similar lower steady state operating temps. Obviously, adding the larger cooler, the stat and a third radiator is the optimum setup, but not everyone is ready to spend that kind of money, particularly if doing two of the three gets you most of the way there.

[Stroked & Blown]

JFP, does the S oil cooler increase capacity at all?

[blue2000s]

Originally Posted by truegearhead

I'll preface this by saying that with the heat index its been 115 here during the day which certainly doesn't help. That aside the car has been heating up beyond half way and even threw the warning light yesterday while sitting in traffic. It will heat up on the highway as well at 70 miles per hour. Both fans are on in fact the car sounds like an airplane trying to take off when its sitting still, the coolant level is great, and it doesn't look like there are too many leaves stuck under the bumper in front of radiators but there is a bit in the back corners. Any ideas what I should be looking for? Could it be as simple as a thermostat, or a coolant flush? I'm driving 400 miles to the Porsches to Oxford car show next week so I need to get this sorted.

Cheers

You shouldn't have to do any "mods" to get your car running correctly. Is it consistantly running warmer than it used to? Coolant doesn't really loose it's cooling ability with age, but it does loose it's ability to fight corrosion. You may have a damaged water pump or as has been mentioned before, blocked radiator.

[JFP in PA]

Originally Posted by Stroked & Blown

JFP, does the S oil cooler increase capacity at all?

Not the oil, because it is on the top of the engine, it is empty while the engine is not running, so the oil level remains the same because the sump capacity is unchanged. Porsche also does not differentiate oil capacities’ between the base and the S; both hold 8.75 L (with filter). When running, however, because of its size, there is more oil transfering heat to more coolant. The coolant capacity does increase slightly because the cooler is always full of coolant.

[Overdrive]

Man, that looks like it's nearly double the size! Is it worthwhile to look into a used one (what sort of lifespan would you guys say these have?) or might as well just go with new?

[Allen K. Littlefield]

JFP, would the deeper sump with the baffles add enough extra oil to be of any cooling assistance? Will the larger oil cooler fit without modifications in a base 2.7 model?

AKL

[JFP in PA]

For about $200 for a new one, you know its exact age and condition, so why even bother looking for a used one?

[JFP in PA]

Originally Posted by Allen K. Littlefield

JFP, would the deeper sump with the baffles add enough extra oil to be of any cooling assistance? Will the larger oil cooler fit without modifications in a base 2.7 model?

AKL

Problem with most sump extension kits is that they only add about ½ quart in capacity, and lowering the sump cover any further is asking for trouble. Such a small increase in total oil capacity (about 5%) is not going to do much.

The “S” cooler is a drop in, bolt up swap for the base unit. Be sure to replace the four o-rings or you will have leaks, and make sure the small hose on top is connected; as the oil cooler is the highest point in the cooling system, it is where air will collect. The line on top of the unit connects to the surge tank in the rear boot to help get any entrained air out of the system.

[Dale_K]

To the OP - it's possible that your water pump is faulty. The plastic impeller blades can crack & break.

[JFP in PA]

Originally Posted by Dale_K

To the OP - it's possible that your water pump is faulty. The plastic impeller blades can crack & break.

Good point, there is no way of knowing then the impeller breaks up........