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Discussion Starter · #1 ·
Hey gang,

Just a quick question per my 987.2 Boxster cool-down post driving midday -- what do you experience after parking per temperature and smell? I sort of remember what my 987.1 S was like, but am a bit paranoid that the engine might be running hotter than it should. Not a crazy hot day today; in the upper 60s here in Boston. I drove about 1/2 hour each way to the registry today; no crazy speeding or aggressive driving. Coolant temp rock solid at 175ºF as usual. Meanwhile, I've noticed a few things these past few weeks per the passenger-side vent as soon as I'm parked:

1) In my closed garage, per the car seemed to take a few hours to cool off; it kept my garage quite warm and I could feel heat waves still radiating out of the vent area.

2) Over the past few weeks, the vent fan turned on for a few minutes after my having parked it about 10 minutes earlier, and it scared the bejesus out of me. Frankly, I was wondering if the thing was going to have some sort of meltdown and was relieved that it shut itself off.

3) In these warmer months, I've now noticed a very faint smell of coolant. However, there have been no low coolant warnings anywhere, and no obviously coolant leaks anywhere. (This smell seemed a bit common on my 987.1 S years back).

Thanks in advance.
 

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I have a 981, but my experience is:

1. Mine takes hours to cool off as well and I too can feel heat waves after the car has been parked for a bit.
2. My fan has never turned on after turning off the car. And we have had some 90 degree days recently.
3. Mine has the typical Porsche hot engine smell. This is hard to describe, Porsche owners just know it. There might be just the slightest scent of coolant mixed in, hard to tell though.
 

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1. Takes quite a while to cool down when stationary. Which is fine with me - that means it doesn't take as long to warm up when I decide I just have to drive it again..
2. My fan does the same thing. Normal on the 987.2. Dunno on the 987.1 - the front fans are different between the .1 and .2, the engine compartment fan logic may also be different.
3. Usual hot engine smell. Not abnormal. Doesn't always do it, or I don't always notice it. There can be a tiny bit of coolant smell just from the cooling system venting if it reaches the release pressure on the cap in the engine compartment. That cap has been updated a number of times - cheap thing to replace and that might fix the smell you're getting.

HTH,
 
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Discussion Starter · #5 ·
Thanks, @deilenberger - All seems to be checking out here from what you're saying. Given I'm nearing 253K, I figured it's less expensive to double-check than run into costly overheating issues.

Yeah - the fan didn't kick in later on the 987.1 so that threw me. Glad to hear this is normal on the 987.2; probably different fan logic and wasn't sure if something was loose somewhere.

It did cross my mind about the coolant cap; I definitely had swapped that out on the 987.1 years back. Figured I had the latest revision on the 2010 so that might be unnecessary. I keep telling myself that as long as the needle stays at 175ºF, all is well. Meanwhile, obviously the cooling system is not running when the engine is off and increased friction in a higher mileage engine might mean more heat... so that was my presumptive logic. :)
 

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On a real hot day, let's say above 90 degrees F. If I drove the car more than an hour and park in my garage. The heat from the car is very noticeable and you can smell the engine. On a few rare occasions, the engine compartment fan kicked on seconds after shutting the car off. This happened when I had a Boxster too and is normal. The fan ran for around 15 seconds and turned off each time. Again, this happens rarely in my case.
 

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Discussion Starter · #7 ·
Neat, @Cantrax - Thanks for chiming in with another valuable data point. This seems to track here, as I did park it in my garage. The fan ran for about a bit under 5 minutes (about 5 minutes AFTER I had already parked) and then shut off. BTW - Is yours a 987.2 as well?
 

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The 987.1 has different fans for different cooling. The front fans to help cool the radiators on hot days in city traffic, while the engine compartment fan to suck hot air out of the motor area after shut down.. You do want to check under your car to see if your car is pushing out any coolant after shut down. You can check the coolant level when cold. May be time for a new cap or rubber ring gasket. The good part of the engine fan is you know that your have heated up your oil to operating temp, which helps remove any fluids that may have accumulated in the oil, like fuel from start up past the piston rings, or moisture in the gas tank from sitting in the garage. Ethanol attracts water, so its a good thing to heat up the oil.
When you heat up the oil it releases the ethanol and other contaminants through the AOS back into the engine combustion chamber and eliminated through the exhaust.
 
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The 987.1 has different fans for different cooling. The front fans to help cool the radiators on hot days in city traffic, while the engine compartment fan to blow cool air on the hot motor after shut down.. You do want to check under your car to see if your car is pushing out any coolant after shut down. You can check the coolant level when cold. May be time for a new cap or rubber ring gasket. The good part of the engine fan is you know that your have heated up your oil to operating temp, which helps remove any fluids that may have accumulated in the oil, like fuel from start up past the piston rings, or moisture in the gas tank from sitting in the garage. Ethanol attracts water, so its a good thing to heat up the oil.
When you heat up the oil it releases the ethanol and other contaminants through the AOS back into the engine combustion chamber and eliminated through the exhaust.
Please correct me if I'm wrong but on the 987.1, I was always under the impression that the fan on the passenger side was an exhaust fan that pulled heat from the engine compartment and not for blowing cool air onto a hot engine. Of course the driver side is the air intake for the engine.
 

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Budman, that engine fan may suck out the hot engine air, when it is on for 30 seconds or so. My point was that that fan running means the oil temps are high enough to evaporate most oil contaminants through the AOS. I wished we had oil temp and pressure gauges in our instrument panel like the 997's have. I'vs seen a couple of conversions, but its very time intensive and only a few shops want to tackle that project.
 
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Please correct me if I'm wrong but on the 987.1, I was always under the impression that the fan on the passenger side was an exhaust fan that pulled heat from the engine compartment and not for blowing cool air onto a hot engine. Of course the driver side is the air intake for the engine.
Same on the 987.2. I was surprised when I got my '09 Boxster how infrequently the engine compartment fan actually ran.. it was rare to hear it turn on. Usually, it was after a spirited drive after parking in my garage, and I think I heard is once when I was stuck in stop/go traffic. The design of the Boxster is clever in that the expansion of the high-pressure zone under the under-cladding is right at the engine area - which is open - creating a vacuum there pulling air through the compartment and out the back of the car, as long as the car is moving at some reasonable speed.

I was also surprised how infrequently the front fans run.. those are rarely heard unless I'm running it in the garage for some reason. The 987.2 has a different control system than the 987.1 - a bit more sophisticated, running the right fan at low speed if the AC is on, then speeding it up when needed to cool the coolant, and finally turning on both fans at max speed if that's needed. Minimum engine loading with maximum needed cooling without wasting energy over-cooling the system.
 
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Discussion Starter · #13 ·
One quick follow-up to this discussion. I went into the engine bay this afternoon to make sure that the engine compartment temperature sensor hadn't fallen off. The good news is that it hadn't, but the sensor was every so slightly not centered and maybe a half centimeter closer to the engine than it should have been. I seriously doubt that my re-centering it will make any difference per temperature readings, but it was good to check to make sure it hadn't fallen off altogether as it's not bolted into place (it's plugged in place with a rubber grommet). Thanks to everyone for their help!
 

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If that sensor stops working, you get a red light on the engine coolant temp gauge. Not only that red light but the engine reverts to its start up mode of fuel map as it thinks the coolant is at the lowest temp readings. This isn't good as the air/fuel ratio is almost raw fuel delivery to ignite the catalytic converters, putting a lot of almost raw gas into the combustion chambers. Almost raw gas could damage the piston skits and cylinder bores.

There is a small metal clip besides the rubber gasket holding that sensor in place. Someone most likely has replaced the sensor and had no awareness of it's not centered position. I read about replacing the coolant temp sensor on P9, which included the discussion of how to remove the retaining clip and pull the sensor out.
 

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The 987.1 engine compartment fan sucks ambient outside air into the engine compartment, to cool the compartment down. That is why it will sometimes run after the boxster s, in my case is shut down. (Not sure if I understand that engineering, in that it should put a pull on your battery).
 

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Keep in mind that even though the temp gauge says 175 the actual temperature might be higher. I have read a number of times that the engineers have it do this so as not to cause anxiety as we watch the temp climb.

Doesn't it seem a bit strange that no matter what, the temp does not go up? Heavy traffic barely moving on a hot day. Climbing a steep hill on a hot day. Etc.

I have read that when it does go up it it serious
 

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My 2013 981 and now 2011 987.2 both exhibited the typical ‘Porsche smell’ after a spirited drive on a hot day. It’s best described as a mix of hot oil and rubber. It’s a beautiful smell.

Ironically, both also exhibit/exhibited a very faint coolant smell after idling in traffic and temps gets up and over 200. It’s only with hotter temps. Both cars thoroughly checked out for leaks and pressure tested. Both received new pressure caps, and don’t lose coolant. I’ve determined it’s just pressure bleeding off through the cap and business as usual. I’ve stopped worrying about it. It’ll drive you mad lol.

The gauge on the dash is very inaccurate and dumbed down sadly, real temps for me with a scan gauge are usually 183-188 as normal and will slide up to 206-208 on a very hot day idling. Dash will always say 175 lol. Others have indicated that the dash gauge won’t move until you’re well into the 220-230 range. Sub 220 is normal operating temps for a modern car.
 

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If you think you smell coolant, start checking your coolant level every day. Buy a replacement o ring for the coolant cap to start with and a jug of Porsche coolant, Mix it 50/50 with distilled water in a glass jug and add to the coolant in the car's filler tube to the mesh screen level each day. You will soon know how much loss you have and this may expose a weeping water pump or worse a hole in a front radiator. Your garage floor under the car may also tell you where to look as fluid may have leaked there as well. Check water pump from behind you seats. Also check the belt with the engine panel open. Not sure where the oil smell is coming from.
I agree that the Porsche coolant system is an example of a complex system that is simplified by smoothing the coolant data. The cars do have an expansion tank that can expel air/fluid or worse crack as its a plastic part.
Lastone- raw gas as when the M97 engine is in startup mode is bad for the piston skirts coatings and cylinder bores. This happens when the oil is very cold. So the less time in that mode the better for a long happy engine life without bore scoring. Bad injectors can/do cause bore scoring, so a can of injector cleaner helps keep those port injectors going over their life cycle.
 
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