Cayman 718 2.0 Base Overheating issue
Discussion
Hi, I have the 2.0 Base 718 Cayman, 2017 which has an overheating issue and its driving me insane.
The problem first happened around 3 months ago, all of a sudden the car developed an overheating issue, it would run up to temp and sit happily at 90o and then all of a sudden the temp starts to rise, fans come up, temp keeps going up and then wham... overheating message.
There are no water leaks and before its mentioned its not a head gasket problem either. Every time it overheats i check the coolant level and although i have to top it up its never that much.. just what has been evaporated really.
At first i thought it was an air block, so it been to an independent that i trust and its been vacuum filled several times. After this it was fine for several days and then back to overheating.
Next on the list was water pump. Changed that along with the thermostat and filler cap. No better
After this i took it to my OPC ( Leicester ) to have the coolant filled properly using there computers to ensure it was filled properly having read that you need the proper Porsche system to open all the valve ensuring there was no air blocks. Total disaster, they wouldn't touch the car without having it checked over first at a cost of nearly £300 only to tell me yes the car overheats and there is a bulletin to replace all coolant pipes.. They never even tried to bleed it as "the computer" says change the pipes at a cost of just shy of £2000... to say i went ballistic at them is an understatement as all they done was charge me 300 quid to tell me what i know and then as the computer says no they didn't even bother to carry out the work i requested. .. anyway moving on
Latest work was to replace the coolant vacuum valve as it was suggested that could be sticking and as its only a £30 part thought may as well try. That's been done but made no difference so we removed the vacuum pipe from the value, sealed it off and it seemed to be OK.. well for a week and a half... now back to over heating.
One thing i have noticed is when it overheats there is no heating.. heating and fan turned up to max and its like the air con is on..
I'm sick of the car to be frank, never want a mid engined car again but even if i were to sell it, it needs fixing.. so hear i am...
I have read of similar issues on other posts... no one seems to have a definitive answer so i am hear to ask the collective...
Any idea's please .... other than cremation that is
The problem first happened around 3 months ago, all of a sudden the car developed an overheating issue, it would run up to temp and sit happily at 90o and then all of a sudden the temp starts to rise, fans come up, temp keeps going up and then wham... overheating message.
There are no water leaks and before its mentioned its not a head gasket problem either. Every time it overheats i check the coolant level and although i have to top it up its never that much.. just what has been evaporated really.
At first i thought it was an air block, so it been to an independent that i trust and its been vacuum filled several times. After this it was fine for several days and then back to overheating.
Next on the list was water pump. Changed that along with the thermostat and filler cap. No better
After this i took it to my OPC ( Leicester ) to have the coolant filled properly using there computers to ensure it was filled properly having read that you need the proper Porsche system to open all the valve ensuring there was no air blocks. Total disaster, they wouldn't touch the car without having it checked over first at a cost of nearly £300 only to tell me yes the car overheats and there is a bulletin to replace all coolant pipes.. They never even tried to bleed it as "the computer" says change the pipes at a cost of just shy of £2000... to say i went ballistic at them is an understatement as all they done was charge me 300 quid to tell me what i know and then as the computer says no they didn't even bother to carry out the work i requested. .. anyway moving on
Latest work was to replace the coolant vacuum valve as it was suggested that could be sticking and as its only a £30 part thought may as well try. That's been done but made no difference so we removed the vacuum pipe from the value, sealed it off and it seemed to be OK.. well for a week and a half... now back to over heating.
One thing i have noticed is when it overheats there is no heating.. heating and fan turned up to max and its like the air con is on..
I'm sick of the car to be frank, never want a mid engined car again but even if i were to sell it, it needs fixing.. so hear i am...
I have read of similar issues on other posts... no one seems to have a definitive answer so i am hear to ask the collective...
Any idea's please .... other than cremation that is
First of all, coolant should not be evaporating. So if it needs topping up regularly, then it means there's a leak.
If you have no heating, then it means that coolant isn't making it to the heater matrix, or it means coolant isn't being pumped around the system. And that suggests eeither a low coolant level, and airlock in the system, or a failed water pump.
As you've replaced the water pump, I'm going to suggest that one of your coolant hoses has a split in it. That would explain the loss of coolant, and how air is getting into the system. And Porsche saying there's a service bulletin to replace colant hoses suggests that it's a known issue.
Take the car to a specialist, tell them what the issues are and you'll probable end up having to spend £500 plus parts cost to replace the hoses.
It COULD be a head gasket failure allowing coolant into the cylinders and exhaust gases into the coolant. The syptoms might be the same, but I'd expect rough running at times too. If the car has ever actually overheated, then one or both blocks or cylinder heads might have warped causing leaks past a good head gasket. In which case it's going to cost a lot more than £2000 to fix.
If you have no heating, then it means that coolant isn't making it to the heater matrix, or it means coolant isn't being pumped around the system. And that suggests eeither a low coolant level, and airlock in the system, or a failed water pump.
As you've replaced the water pump, I'm going to suggest that one of your coolant hoses has a split in it. That would explain the loss of coolant, and how air is getting into the system. And Porsche saying there's a service bulletin to replace colant hoses suggests that it's a known issue.
Take the car to a specialist, tell them what the issues are and you'll probable end up having to spend £500 plus parts cost to replace the hoses.
It COULD be a head gasket failure allowing coolant into the cylinders and exhaust gases into the coolant. The syptoms might be the same, but I'd expect rough running at times too. If the car has ever actually overheated, then one or both blocks or cylinder heads might have warped causing leaks past a good head gasket. In which case it's going to cost a lot more than £2000 to fix.
Thanks @LunarOne, although i appreciate where your coming from i'm afraid i have to disagree
When water gets to over 100o it turns to steam and some will evaporate... the overheating warning kicks in at 122o.. that HOT.... the car stinks and some of the water will turn to steam.. the filler system is not sealed so it can deal with any overflow therefore the steam / condensation.. call it what you want.. it will disappear. Its not a lot that i add back in, just enough to get it to the fill limit
I do agree with the Heater Matrix issue but then again i know for a fact its been vacuum filled several times so how can there be an air lock still.. this is why i took it to the OPC but they were useless.
I personally still think an air lock is the issue... just no idea how to resolve it
The reason i do not believe its a head gasket is when it is running properly it is perfect.. no issue's with running at all.. admittedly its not been checked but i know the car, i also ( currently ) run an Vantage and Supercharged RR but have had Maserati's, TVR and RS Audi's ... i know when a car is running properly and this is one of them ( apart from when it becomes a steam engine ), i'm sure with just 4 cylinders if it was engine related I would know about it :-). However i would be the first to say i'm no mechanic but i do work on my cars.... happy to replace parts etc and get my hands dirty... just going to have to take it that its not an engine related issue, sorry.
Finally i know there are no leaks because i have a polished garaged concrete floor... when its overheated before i have left the car inside.... checked it the day after an nothing.. no water strains anywhere..
I'm not afraid to spend money on it, i just want it fixed..... i don't trust the OPC, they refused to let me actually speak to the engineer and had to relay the symptoms via the front desk ( i don't personally believe the engineer who worked on it even knew why it was in ). The bulletin refers to a damaged waterpump feeding water into the vacuum lines hence them wanting to replace it all. They assumed that as i replaced the water pump it was at fault, where in fact when we did replace it there were no symptoms of it actually ever leaking. Unfortunately they came across someone that actually has an idea of what they are talking about and i let them have both barrels.... it is unacceptable to carry out a vehicle check which pretty much was simply checking a computer, noticing there was a bulletin and using that to assume that's the reason.I have no issue if that is actually the case... but i know for a fact they didn't even remove a pipe to check if its was an issue or not.
I digress... they really annoyed me as you can probably tell.
Thank you for your input, i appreciate you taking the time to respond .. i think a specialist is the way to go.. just hoping someone on the forum has had a similar issue and can let me know what was done.
When water gets to over 100o it turns to steam and some will evaporate... the overheating warning kicks in at 122o.. that HOT.... the car stinks and some of the water will turn to steam.. the filler system is not sealed so it can deal with any overflow therefore the steam / condensation.. call it what you want.. it will disappear. Its not a lot that i add back in, just enough to get it to the fill limit
I do agree with the Heater Matrix issue but then again i know for a fact its been vacuum filled several times so how can there be an air lock still.. this is why i took it to the OPC but they were useless.
I personally still think an air lock is the issue... just no idea how to resolve it
The reason i do not believe its a head gasket is when it is running properly it is perfect.. no issue's with running at all.. admittedly its not been checked but i know the car, i also ( currently ) run an Vantage and Supercharged RR but have had Maserati's, TVR and RS Audi's ... i know when a car is running properly and this is one of them ( apart from when it becomes a steam engine ), i'm sure with just 4 cylinders if it was engine related I would know about it :-). However i would be the first to say i'm no mechanic but i do work on my cars.... happy to replace parts etc and get my hands dirty... just going to have to take it that its not an engine related issue, sorry.
Finally i know there are no leaks because i have a polished garaged concrete floor... when its overheated before i have left the car inside.... checked it the day after an nothing.. no water strains anywhere..
I'm not afraid to spend money on it, i just want it fixed..... i don't trust the OPC, they refused to let me actually speak to the engineer and had to relay the symptoms via the front desk ( i don't personally believe the engineer who worked on it even knew why it was in ). The bulletin refers to a damaged waterpump feeding water into the vacuum lines hence them wanting to replace it all. They assumed that as i replaced the water pump it was at fault, where in fact when we did replace it there were no symptoms of it actually ever leaking. Unfortunately they came across someone that actually has an idea of what they are talking about and i let them have both barrels.... it is unacceptable to carry out a vehicle check which pretty much was simply checking a computer, noticing there was a bulletin and using that to assume that's the reason.I have no issue if that is actually the case... but i know for a fact they didn't even remove a pipe to check if its was an issue or not.
I digress... they really annoyed me as you can probably tell.
Thank you for your input, i appreciate you taking the time to respond .. i think a specialist is the way to go.. just hoping someone on the forum has had a similar issue and can let me know what was done.
It’s unlikely to be a pipe unless they can collapse and reduce flow somewhere which seems pretty unlikely.
The coolant system is sealed but there will be a pressure release that allows a controlled escape of coolant at a certain point. The coolant will need to be well above 100 degrees before it can evaporate or vaporise because the boiling point is raised significantly by being kept under pressure and probably by the ingredients of the coolant as well. Actual running temps well over 100 are not unusual on modern cars.
Most likely cause would be a lack of flow which could be caused by either a pump problem or sticking stat, both of which you have done but are you sure there’s only one stat and pump on these engines? I think there is an auxiliary electric pump for the chargecooler (which wouldn’t cause your issues) but I don’t know if there is any others.
I have replaced the front crossover pipes on my 2.5 718 and had the coolant system drained a few times on my 2.0 but I’m not sure how the various controls are set up other than to say it’s a fairly complex system and I wouldn’t be surprised if there were additional pumps or valves that can add to or restrict flow.
Vac filling is generally a pretty reliable way to go on these but when I have had airlocks filling them it is usually fairly obvious straight away and the easiest way to actively bleed them that I have found is to release the trapped air by pulling the top pipe partly off each of the radiators. Once you have most of it out it starts to circulate properly and seems to self-bleed any little that remains.
Finally, it’s worth knowing that the temperature gauge tells lies. It will go to 90 degrees and stay there to reassure you, it will only read a higher temperature once it goes above a certain threshold. If you want to see the actual temperature get a cheap obd reader and you can see the true reading in live data. This might give you some idea of how much the temperatures are actually varying even when the dash says everything is ok.
The coolant system is sealed but there will be a pressure release that allows a controlled escape of coolant at a certain point. The coolant will need to be well above 100 degrees before it can evaporate or vaporise because the boiling point is raised significantly by being kept under pressure and probably by the ingredients of the coolant as well. Actual running temps well over 100 are not unusual on modern cars.
Most likely cause would be a lack of flow which could be caused by either a pump problem or sticking stat, both of which you have done but are you sure there’s only one stat and pump on these engines? I think there is an auxiliary electric pump for the chargecooler (which wouldn’t cause your issues) but I don’t know if there is any others.
I have replaced the front crossover pipes on my 2.5 718 and had the coolant system drained a few times on my 2.0 but I’m not sure how the various controls are set up other than to say it’s a fairly complex system and I wouldn’t be surprised if there were additional pumps or valves that can add to or restrict flow.
Vac filling is generally a pretty reliable way to go on these but when I have had airlocks filling them it is usually fairly obvious straight away and the easiest way to actively bleed them that I have found is to release the trapped air by pulling the top pipe partly off each of the radiators. Once you have most of it out it starts to circulate properly and seems to self-bleed any little that remains.
Finally, it’s worth knowing that the temperature gauge tells lies. It will go to 90 degrees and stay there to reassure you, it will only read a higher temperature once it goes above a certain threshold. If you want to see the actual temperature get a cheap obd reader and you can see the true reading in live data. This might give you some idea of how much the temperatures are actually varying even when the dash says everything is ok.
Steve H said:
It s unlikely to be a pipe unless they can collapse and reduce flow somewhere which seems pretty unlikely.
The coolant system is sealed but there will be a pressure release that allows a controlled escape of coolant at a certain point. The coolant will need to be well above 100 degrees before it can evaporate or vaporise because the boiling point is raised significantly by being kept under pressure and probably by the ingredients of the coolant as well. Actual running temps well over 100 are not unusual on modern cars.
Most likely cause would be a lack of flow which could be caused by either a pump problem or sticking stat, both of which you have done but are you sure there s only one stat and pump on these engines? I think there is an auxiliary electric pump for the chargecooler (which wouldn t cause your issues) but I don t know if there is any others.
I have replaced the front crossover pipes on my 2.5 718 and had the coolant system drained a few times on my 2.0 but I m not sure how the various controls are set up other than to say it s a fairly complex system and I wouldn t be surprised if there were additional pumps or valves that can add to or restrict flow.
Vac filling is generally a pretty reliable way to go on these but when I have had airlocks filling them it is usually fairly obvious straight away and the easiest way to actively bleed them that I have found is to release the trapped air by pulling the top pipe partly off each of the radiators. Once you have most of it out it starts to circulate properly and seems to self-bleed any little that remains.
Finally, it s worth knowing that the temperature gauge tells lies. It will go to 90 degrees and stay there to reassure you, it will only read a higher temperature once it goes above a certain threshold. If you want to see the actual temperature get a cheap obd reader and you can see the true reading in live data. This might give you some idea of how much the temperatures are actually varying even when the dash says everything is ok.
Coolant / water mix boiling point is around 105 C. But in a pressured system it is more like 130 C - obviously the higher the pressure release valve / cap setting, the higher the boilng point. But I don't know what the 718 system is set to. Obviously it can start evaporating at much lower temperatures but not in a closed system. Needing frequent top ups - even very small ones - is a sign of a leak or air lock.The coolant system is sealed but there will be a pressure release that allows a controlled escape of coolant at a certain point. The coolant will need to be well above 100 degrees before it can evaporate or vaporise because the boiling point is raised significantly by being kept under pressure and probably by the ingredients of the coolant as well. Actual running temps well over 100 are not unusual on modern cars.
Most likely cause would be a lack of flow which could be caused by either a pump problem or sticking stat, both of which you have done but are you sure there s only one stat and pump on these engines? I think there is an auxiliary electric pump for the chargecooler (which wouldn t cause your issues) but I don t know if there is any others.
I have replaced the front crossover pipes on my 2.5 718 and had the coolant system drained a few times on my 2.0 but I m not sure how the various controls are set up other than to say it s a fairly complex system and I wouldn t be surprised if there were additional pumps or valves that can add to or restrict flow.
Vac filling is generally a pretty reliable way to go on these but when I have had airlocks filling them it is usually fairly obvious straight away and the easiest way to actively bleed them that I have found is to release the trapped air by pulling the top pipe partly off each of the radiators. Once you have most of it out it starts to circulate properly and seems to self-bleed any little that remains.
Finally, it s worth knowing that the temperature gauge tells lies. It will go to 90 degrees and stay there to reassure you, it will only read a higher temperature once it goes above a certain threshold. If you want to see the actual temperature get a cheap obd reader and you can see the true reading in live data. This might give you some idea of how much the temperatures are actually varying even when the dash says everything is ok.
Edited by Discombobulate on Sunday 27th July 21:02
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