Failure sensor
02-27-2014, 09:53 AM
#1
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Failure sensor
07 .1 GT3: Have been getting a "Failure sensor" and the coolant temp indicator light flashing. Only in sub 50F temps. Consequently Oil temp gauge seems to be off as well. Have already replaced thermostat insert, so pretty sure I have no "stuck open" thermostat.
Pretty sure the culprit is the coolant temp sensor (#24 in the picture below). From the PET I am not entirely sure where it is located though.
To gain access for an inspection / replacement, my guess is to remove the alternator. Can anyone confirm before I start digging in?
Thanks, Joost
Pretty sure the culprit is the coolant temp sensor (#24 in the picture below). From the PET I am not entirely sure where it is located though.
To gain access for an inspection / replacement, my guess is to remove the alternator. Can anyone confirm before I start digging in?
Thanks, Joost
02-27-2014, 10:47 AM
#2
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That spot near 13 is where the water pump is.
Have you pulled the codes with a dura metric? What codes?
Have you pulled the codes with a dura metric? What codes?
02-27-2014, 02:16 PM
#4
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I think this thread is related and might help you.
https://rennlist.com/forums/997-gt2-...ain-cel-2.html
https://rennlist.com/forums/997-gt2-...ain-cel-2.html
02-27-2014, 02:44 PM
#5
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I thought I remembered what trackcar just linked to reading a while back, post #29 in thread he linked to:
@flyingpenguin, look at this:
http://www.suncoastparts.com/product...997GT3TRAGT3RS
@flyingpenguin, look at this:
http://www.suncoastparts.com/product...997GT3TRAGT3RS
02-27-2014, 03:14 PM
#6
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Porsche Tech Notice:
Not a frequent issue, but one that has the potential for misdiagnosis. Typically the indicators are a low temperature display, or the display only works sporadically. When a technician checks the fault codes in the DME control unit, the fault codes are P2181 (thermostat stuck open) and P3081 (engine coolant temperature implausible). These issues can occur independently of each other, or at the same time - depending on driving style and geograhic region.
The main cause is a blocked valve, see the first photo. Another idication of a defective disc valve is when the oil temperature and coolant temperature are almost identical in the warm-up phase. As a rule, the coolant temperature should be higher than the oil temperature.
Deformation of the sealing ring (photo 2) can mean that the disc valve can no longer be guaranteed. As a result, an additional cooling circuit is opened via transmission cooling in the warm-up phase and the engine is slow to reach operating temperature. Photo 2 shows the cut-away view of the valve, and the arrow is pointing at the correct position of the sealing ring.
If the symptoms above are verified by an authorized technician, a visual inspection and function test of the valves are recommended before replacing.
Always consult an authorized Porsche technician for diagnosing any problems, especially if your car is under the factory warranty.
For 2007-12 GT3 & GT3 RS models.
Not a frequent issue, but one that has the potential for misdiagnosis. Typically the indicators are a low temperature display, or the display only works sporadically. When a technician checks the fault codes in the DME control unit, the fault codes are P2181 (thermostat stuck open) and P3081 (engine coolant temperature implausible). These issues can occur independently of each other, or at the same time - depending on driving style and geograhic region.
The main cause is a blocked valve, see the first photo. Another idication of a defective disc valve is when the oil temperature and coolant temperature are almost identical in the warm-up phase. As a rule, the coolant temperature should be higher than the oil temperature.
Deformation of the sealing ring (photo 2) can mean that the disc valve can no longer be guaranteed. As a result, an additional cooling circuit is opened via transmission cooling in the warm-up phase and the engine is slow to reach operating temperature. Photo 2 shows the cut-away view of the valve, and the arrow is pointing at the correct position of the sealing ring.
If the symptoms above are verified by an authorized technician, a visual inspection and function test of the valves are recommended before replacing.
Always consult an authorized Porsche technician for diagnosing any problems, especially if your car is under the factory warranty.
For 2007-12 GT3 & GT3 RS models.
LOL, right, except it happened to all four of mine and all were misdiagnosed and got new thermostats first
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03-04-2014, 10:33 AM
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Many thanks again to Spyerx and TRAKCAR for pointing this out. Old part removed and diagnosed to be malfunctioning. Instructions as per https://rennlist.com/forums/8466616-post29.html are very accurate.
Little o-ring that is the culprit here was stuck inside the valve and out of sight. Took a bit of prying to get it out.
New part installed, fluid topped off, and ran the engine for a bit. Kept an eye on the valve actuating (ie. closing), which it did not. My assumption was that it should, with coolant, engine and ambient temps below 50F.
Guess the next step is to take her for a drive and see how quickly everything warms up and if no CEL's come back. Will revert.
Little o-ring that is the culprit here was stuck inside the valve and out of sight. Took a bit of prying to get it out.
New part installed, fluid topped off, and ran the engine for a bit. Kept an eye on the valve actuating (ie. closing), which it did not. My assumption was that it should, with coolant, engine and ambient temps below 50F.
Guess the next step is to take her for a drive and see how quickly everything warms up and if no CEL's come back. Will revert.
Last edited by flyingpenguin; 03-05-2014 at 11:08 PM.
03-06-2014, 01:08 PM
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..And the saga continues.
Drove car this am to work. About 20 mins. commute, ambient about 48F. Coolant temp would go up very slowly, and just before I get to the office, "Failure sensor" pops up. Pending codes P2181 and 3081 again.
Checked the actuation of the pneumatic lever before installation, checked out. I guess it's the change over valve that needs inspection now.
Drove car this am to work. About 20 mins. commute, ambient about 48F. Coolant temp would go up very slowly, and just before I get to the office, "Failure sensor" pops up. Pending codes P2181 and 3081 again.
Checked the actuation of the pneumatic lever before installation, checked out. I guess it's the change over valve that needs inspection now.
03-07-2014, 10:45 AM
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OK, problem solved.
Turns out that the oil temp sensor on the tranny cooler was compromised (see pic). Not very visibly so, but enough to fool the DME to the point where it would not operate the coolant shut-off valve.
My assumption is that the sensor must have gotten bumped / cracked during the rebuild (syncro's and LSD) under CPO last summer. It's the same part# as the coolant temp sensor on the M96 engine. Luckily I have a few M96 parts lying around from the Boxster engine rebuild, and this sensor was one of them.
Turns out that the oil temp sensor on the tranny cooler was compromised (see pic). Not very visibly so, but enough to fool the DME to the point where it would not operate the coolant shut-off valve.
My assumption is that the sensor must have gotten bumped / cracked during the rebuild (syncro's and LSD) under CPO last summer. It's the same part# as the coolant temp sensor on the M96 engine. Luckily I have a few M96 parts lying around from the Boxster engine rebuild, and this sensor was one of them.
