Cooling System Fault on 2015 991 C4 - Advise.

[PJ63]

Hi Guys

Driving back from the Southern Regional Concours event at Avington Park last weekend I had the following message come up: 'Cooling System Fault'. Hence I spoke to Porsche Guildford & they had it relayed in straight away to sort out. That was last Monday & it's now been with them for a week & they seem to have changes loads valves/seals as well as the vacuum pump itself twice & are still getting the error message & are now saying that the Diaphragm in the Airbox is not working which they think is causing all the problem.
The car is less than a year old with only 3000 miles on the clock, so not exactly highly used. Any advise or knowledge on the above would be appreciated.

 

[Pieman7]

Hi there I'd be fuming that they have had it that long and still can't find the problem. Lucky it's still in warrenty hope they given you something super to drive round in. I wouldn't be to pleased they say that the diaphragm might be causing the problem I want to here a bit more of a positive answer seeing how much the car costs. The problem if the computers they plug don't tell them exactly what's wrong there thinking is replace most things till we find it. Good luck feeling the frustration

 

[MickHudson]

I had a similar problem on my 991 'Cooling system fault contact dealer'

before I booked it in I had a cursory look under the rear of the car and noticed a small rubber pipe had disconnected from the exhaust valve on the OSR. I popped it back on but still booked the car in. The fault code was reset at the dealer and the tech told me I had resolved the problem !

Im sure the OPC will have checked these so can only assume if its the problem I had, is a vacuum issue that can set off the coolant system fault code. All to do with thermo settings on the engine

 

[PJ63]

Sorry as I meant to reply when I got the car back to let you know what the issue was, for anyone else with a similar problem.

So after a week of Guildford having the car & having replaced various things that the computer was telling them, the technician then used old fashioned mechanical diagnostic testing to confirm that it was the diaphragm in the airbox was not working & as that is mechanical with no electronic wizardery the computer couldn't find the root cause of the warning message. When I asked why the diaphragm on 2015 3000 mile car would stop working there only reply was maybe a manufacture issue. So a good example of the computer not knowing everything & good old fashioned mechanical expertise might be more useful. Anyway all fixed now & working fine.

Just as a sub-note to say that although annoying this is the first problem I've had with any of my 911,s & this is my 5th one I've had from 996's, 997's & a previous 991, so not all doom & gloom.

 

[carlperrin]

Hi, I got the message (cooling system fault visit workshop) yesterday on my 981 Boxster.
Where exactly is the pipe you mentioned, can you see it from under the car or do you need to access from above?
any help appreciated.

 

[tscaptain]

Hi, I got the message (cooling system fault visit workshop) yesterday on my 981 Boxster.
Where exactly is the pipe you mentioned, can you see it from under the car or do you need to access from above?
any help appreciated.

This is a 4 year old thread so you may well not get a response. I would suggest starting a new one on the Boxster forum.

 

[AndrewCS]

Hi, I got the message (cooling system fault visit workshop) yesterday on my 981 Boxster.
Where exactly is the pipe you mentioned, can you see it from under the car or do you need to access from above?
any help appreciated.

If it is the vacuum line / pipe / hose to either of the PSE valve actuators ... just look under the car behind each rear wheel.

The lines are crimped on to a `nipple` on the actuator ... one of my `nipples` sheared leaving the hose hanging loose ... new actuator fitted under warranty.

NB ... the vacuum system operates several items / valves in the cooling system hence other issues may be present (thanks to this forum for highlighting this when I had my issue).

 

[keneccles]

Had a similar problem a while back on my 991 - yellow warning message re coolant system. Porsche dealer took it in under warranty and confirmed that one of the vacuum driven change over valves was not operating, so they swapped it out telling me it is a fairly common fault. They also replaced another change over valve a few weeks later when I got another yellow warning telling me that the 4WD drive system had shut down - again they said they had come across this before. Oh and they also swapped out nylon bushings on the brake pedal - car is manual - on hot days, this was causing the pedal to stay partially depressed. Apparently this was also a well known fault though no recalls?

 

[Sasssy2]

I’m having same message on my 2017 718 with 45,000 miles on it. Warranty just expired like 9 weeks ago. Want to get it fixed before we sell it. Or trade it in . They can’t pinpoint problem. "Coolant faulty see Porsche service " or something like that. It does sound like a vacuum seal? Help me if you can . Thanks and Merry Christmas to all of you and stay safe!

 

[AndrewCS]

I’m having same message on my 2017 718 with 45,000 miles on it. Warranty just expired like 9 weeks ago. Want to get it fixed before we sell it. Or trade it in . They can’t pinpoint problem. "Coolant faulty see Porsche service " or something like that. It does sound like a vacuum seal? Help me if you can . Thanks and Merry Christmas to all of you and stay safe!

- Coolant level OK ?

- Are all the car`s functions operating OK ?

- If you have the Sports Exhaust ... are the lines to the valve actuators connected OK ?

Apart from those you`ll need a diagnostic check to find the issue

 

[carlperrin]

Do you have PSE?
I took my car to a Porsche Specialist in the Cotswolds, and we think the problem was possibly something to do with the solenoid valves/actuators, the fault message that this problem throws up is obviously misleading as all temps and cooling were checked and they were fine.
Good luck I hope you get your problem resolved.
Merry Christmas
Carl

 

[Chips600]

Hi Guys,

I appreciate this post is a few years in the making but, as with many 991 owners I now have the "Fault cooling system" warning. I took to local Porsche garage and they confirmed COV is the issue but cannot tell me which one, which I thought a bit weird? The cost to replace one valve was.....expensive!

Having read many many posts about the COV, I was thinking about doing the replacement myself. I've looked at the drawings I can find online and it appears that the COV for coolant is just inside the rear wing, drivers side. Has anyone done this replacement before, is it a full bumper removal or is there an easier way?

TIA