ENGINE CONTROL FAULT
12-04-2016, 11:28 PM
#91
Rennlist Member
Thats definitely the thermostat. I've had it twice stuck open like you (front blower fan stays on and wont turn off - car runs a bit lumpy at idle as water temps are low). Its better stuck open than closed (Ive had that too) where the engine will overheat...
12-15-2016, 02:04 PM
#94
Do you know why is that? Doesn't make any sense. And finally, do you have a link to the system used by Porsche? I understand all mid-engine Porsches don't have a regular thermostat, but rather, an ECU-controlled one. In fact, regular coolant temp on 981s in normal mode is 230ºF, but 190º in sport/sport+ (coolant gauge always say 194 on those cars). Curious what kind of thermostat is in there. Thx.
12-15-2016, 02:07 PM
#95
Nordschleife Master
Originally Posted by elp_jc
Do you know why is that? Doesn't make any sense. And finally, do you have a link to the system used by Porsche? I understand all mid-engine Porsches don't have a regular thermostat, but rather, an ECU-controlled one. In fact, regular coolant temp on 981s in normal mode is 230ºF, but 190º in sport/sport+ (coolant gauge always say 194 on those cars). Curious what kind of thermostat is in there. Thx.
12-15-2016, 03:51 PM
#96
Rennlist Member
The thermostat is the same ECU controlled type for 981 & 991 and they fail in both cars regularly. We created a whole thread on the subject on this board years ago where we posted pictures of our failed units etc
The fans stay on as precautionary as previously stated.
The fans stay on as precautionary as previously stated.
12-16-2016, 03:58 PM
#98
Anyway, I'm going to look for that thread, to understand the system better. But the search function is crap on this site. If somebody has it handy, I'd appreciate it
.
12-16-2016, 04:25 PM
#99
Nordschleife Master
Originally Posted by elp_jc
I guess we don't have the same definitions of thermostat vs coolant temp sensor. A Thermostat is just a device (electronic or mechanical) that allows water to pass. A sensor is what transmit the temperature to the ECU. If the thermostat is stuck open, the fans would seldom need to turn on for obvious reasons. If the SENSOR goes bad, then you guys would be right. Which one is it??? Anyway, I'm going to look for that thread, to understand the system better. But the search function is crap on this site. If somebody has it handy, I'd appreciate it.
Anyway, I'm going to look for that thread, to understand the system better. But the search function is crap on this site. If somebody has it handy, I'd appreciate it.https://rennlist.com/forums/991-gt3-...explained.html
12-17-2016, 10:31 PM
#100
Yep, I knew that much. Thanks for the link, but why did you delete the pictures on your first post? I'm almost as lost as I was before
. But yes, it baffles the mind why in the world our cars don't have a simple 185ºF mechanical thermostat like the rest of automobiledom. Since nobody else uses it, it can't be saving that much fuel. Anyway, my next question for those of us who always drive in sport mode: Are we asking for trouble sooner, since DME is constantly keeping the thermostat energized? Or is that the opposite? Inquiring minds want to know.
Now, after reading that entire thread, my question still stands: Why the hell do fans operate all the time with a 'failure'? The thermostat is a 221ºF mechanical device, which can be heated by the DME to lower coolant temp to 185ºF (by opening sooner). Therefore, if there's a 'failure', the thermostat would start to open normally at 216ºF (and fully at 239), like if we had 'normal' mode on, so why run the fans at anything lower than that, if sensors are working correctly? Am I missing something? THAT is what still doesn't make any sense. Definitely another typical German over-engineered system for a problem that didn't exist
.
. Thanks for the link, but why did you delete the pictures on your first post? I'm almost as lost as I was before. But yes, it baffles the mind why in the world our cars don't have a simple 185ºF mechanical thermostat like the rest of automobiledom. Since nobody else uses it, it can't be saving that much fuel. Anyway, my next question for those of us who always drive in sport mode: Are we asking for trouble sooner, since DME is constantly keeping the thermostat energized? Or is that the opposite? Inquiring minds want to know. Now, after reading that entire thread, my question still stands: Why the hell do fans operate all the time with a 'failure'? The thermostat is a 221ºF mechanical device, which can be heated by the DME to lower coolant temp to 185ºF (by opening sooner). Therefore, if there's a 'failure', the thermostat would start to open normally at 216ºF (and fully at 239), like if we had 'normal' mode on, so why run the fans at anything lower than that, if sensors are working correctly? Am I missing something? THAT is what still doesn't make any sense. Definitely another typical German over-engineered system for a problem that didn't exist
.
12-17-2016, 10:42 PM
#101
Nordschleife Master
Originally Posted by elp_jc
Yep, I knew that much. Thanks for the link, but why did you delete the pictures on your first post? I'm almost as lost as I was before. But yes, it baffles the mind why in the world our cars don't have a simple 185ºF mechanical thermostat like the rest of automobiledom. Since nobody else uses it, it can't be saving that much fuel. Anyway, my next question for those of us who always drive in sport mode: Are we asking for trouble sooner, since DME is constantly keeping the thermostat energized? Or is that the opposite? Inquiring minds want to know.
Now, after reading that entire thread, my question still stands: Why the hell do fans operate all the time with a 'failure'? The thermostat is a 221ºF mechanical device, which can be heated by the DME to lower coolant temp to 185ºF (by opening sooner). Therefore, if there's a 'failure', the thermostat would start to open normally at 216ºF (and fully at 239), like if we had 'normal' mode on, so why run the fans at anything lower than that, if sensors are working correctly? Am I missing something? THAT is what still doesn't make any sense. Definitely another typical German over-engineered system for a problem that didn't exist.
. Thanks for the link, but why did you delete the pictures on your first post? I'm almost as lost as I was before. But yes, it baffles the mind why in the world our cars don't have a simple 185ºF mechanical thermostat like the rest of automobiledom. Since nobody else uses it, it can't be saving that much fuel. Anyway, my next question for those of us who always drive in sport mode: Are we asking for trouble sooner, since DME is constantly keeping the thermostat energized? Or is that the opposite? Inquiring minds want to know. Now, after reading that entire thread, my question still stands: Why the hell do fans operate all the time with a 'failure'? The thermostat is a 221ºF mechanical device, which can be heated by the DME to lower coolant temp to 185ºF (by opening sooner). Therefore, if there's a 'failure', the thermostat would start to open normally at 216ºF (and fully at 239), like if we had 'normal' mode on, so why run the fans at anything lower than that, if sensors are working correctly? Am I missing something? THAT is what still doesn't make any sense. Definitely another typical German over-engineered system for a problem that didn't exist
.The computer knows there's a problem in the coolant system since it controls the thermostat and the engineers introduced a " fail safe " in its operation,it's my only explanation.
12-17-2016, 10:55 PM
#102
Thanks a lot anyway. I'll keep looking, and post them here if I find any. At any rate, Porsche must have changed something, since it's not a wide-spread problem. Hopefully my 2016 will be immune to that. And yes, will continue using sport mode to keep oil temp around 200, rather than 230.