Porsche 911 UK Enthusiasts Online Community Discussion Forum GB

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Cooling System Fault Visit Garage

eme160

Silverstone
Joined
4 Sep 2014
Messages
135
The cooling system fault popped up the other day so I guess I have a changeover valve failing. Heater playing up a little aswell so maybe this cov. The question I have is if I find the cov that is playing up and replace with a new one will the fault warning clear itself or do you need a fault code reader to clear it? Car is out of warranty and looking farward to actually being able to work on it a little.
Many thanks in advance :D
 
Whilst i've changed many of these valves over the years i've always cleared the fault code so i can't really answer your question ..

I would say that if you are planning on doing a bit of work on your car these days then a good code reader is a sensible investment .

Technically once the car had realised there wasn't an issue anymore you would stop getting the warning message .. the amount of warm up cycles for that to happen and i'm unsure ..

Im guessing a couple of drives and it should clear ... don't hold me to that though :D

The issue is not always the valves .. as they are all interlinked then a split in a vacuum pipe at any one of these will also cause your fault .
 
I think the fault code stays until it is cleared (I use an ICarSoft POR II) - a bit like the airbag warning if you remove a seat. This 'cooling fault' thing is a real pain in the rear on 991.1s. I've had three failures so far (heating failed, symposer stuck and my current one which I haven't got to the bottom of yet). Only the last one caused the 'cooling fault'.

On looking into this in more detail, it seems (and this is something of a guess because I'm not a Porsche engineeer) that all of these solenoids are just a 12V coil, and the DME doesn't know if the solenoid/valve has done anything when it activates the solenoid. The only time is does know that something is amiss is when the engine temp doesn't do quite what is expected because the engine coolant shut-off valve hasn't opened or closed - the DME only monitors the coolant temperature. As DeMort said it can be anything in the vacuum system - a leaking vaccuum pipe, faulty engine coolant shut-off valve, leaking solenoid valve (one or more of 8) or failing vacuum pump. It's not a Porsche engineering triumph, that's for sure. I'm going to replace all the rest when I do the next service if I can get at them.

When you order a new change-over valve make sure you get the adapter harness as well. The new ones don't fit the old plug. Also, if you are buying an ICarSoft tool make sure it's the latest v3 - that can code the battery as well. The tool is also good for clearing the fault and then you can see if it returns. Sometimes these valves are just sticky.

The good news is that you can usually drive around normally quite happily with this 'fault' - just keep an eye on the engine temps. The only thing I've noticed on this last fault is that the oil temp isn't quite as high as it used to be. But then again, it is winter ...
 
:agree:

One valve fails and they all fail .. the car can't see the operation of any valve other than the temp one and it works that out by temp readings .

The valves and it just sends an earth signal so it has no idea if its worked or not .. things like sound symposium don't matter .. coolant is the only one that does and that's not huge .

Dash fault may well stay on .. i'm unsure there .. i know that any DME fault if not active will clear over time but for things like lambda sensors that's at least 40 cycles with a cycle being a complete warm up ... drive and shut down till cold ... these and i just don't know .

These valves back when i was at OPC were subject to a recall .. we replaced all of them .. 6 months later and another recall .. we replaced them all again !!!

Pretty sure there has been another update to this part hence the wiring loom needed .

They still fail though as yours has done .. to find the valve though .. at work i smoke test the line then if nothing there i check each valve.. blow through .. powered up and blow through powered down.. can't blow through each time or its faulty .

Blow through and its actually a vacuum gauge connected but either will prove a faulty valve .
 
My experience with my 2014 C4S was coolant warning - turned out to be the sound symposer CoV. But it was simply the vacuum pipe had disconnected - no issues with the CoV per se. It was sorted under warranty but it's diagnosing which part of the system is at fault that can take time because there are 9 or so in the system depending on the model as deMort suggests. Don't know about clearing the fault code but worth checking if it's simply a disconnected line.
 
Thanks for all your replies. Really helpful information. Not sure when I'll tackle this as not urgent. Will keep you posted 👍
 
I seem to remember it being a Pierburg part and there have been several iterations. Unless there's been another update, I think we're on 'F' type now (but happy to be corrected). Sort of says it all :roll:
 
Mine also throws this fault periodically, usually during long journeys where the temp seems to get to the upper limits. I bought a very cheap code reader off Amazon, which works great for clearing the fault code.

Some useful info here, so might attempt some DIY troubleshooting in the Spring :thumb:
 
By smoke tester and i mean something like this ..

https://www.ebay.co.uk/itm/16428023...enc:1P0hqS56YRS2azmI_vyKz9w82&norover=1&mkevt

A bit of kit you won't often use but a god send for faults like this .

My old OPC didn't have one of these .. i had to join an INDY to find out it even existed ..

Shame there's not a group club here where things like this could be bought and sent out to members as and when needed ... a subscription service for unusual tools .
 
I've had exactly the same recurring but intermittent fault on my car. Came up when I got the car and was told it was a valve leaking.
Fault stayed away for a few weeks so ignored it and then it popped up again so I took it to Porsche centre, showed up on the diagnostic as leaking vacuum pipe and was traced to the gearbox.
New vacuum pipe fitted and so far it's been fault free.
 

Attachments

  • img_20211129_wa0000_646.jpg
    img_20211129_wa0000_646.jpg
    36.6 KB · Views: 3,446
I didn't know about smoke detectors either - thank you deMort! I've just ordered one (I'm a complete sucker for tools - I seem to collect them).

Just for reference the part numbers are:

valve: P7PP906283F
harness: P99161294400

You can get them from an OPC or Design911 (I use them because you can just order via a web page rather than working your way through the OPC service people) and probably elsewhere. The cost (inc VAT) is around £78 for the pair.

Most of my valves are the 'C' version (which fail). The 'F' version is the latest. How you can take *six* revisions to get something as simple as this right beats me.
 
Forrester said:
... How you can take *six* revisions to get something as simple as this right beats me.

Engineers at Pierburg are obviously big fans of Darwin :lol:
 
Forrester said:
I didn't know about smoke detectors either - thank you deMort! I've just ordered one (I'm a complete sucker for tools - I seem to collect them).

Just for reference the part numbers are:

valve: P7PP906283F
harness: P99161294400

You can get them from an OPC or Design911 (I use them because you can just order via a web page rather than working your way through the OPC service people) and probably elsewhere. The cost (inc VAT) is around £78 for the pair.

Many thanks :thumb:

Are these parts # specific to Gen1 or Gen2, or are they now interchangeable?
 
Thanks for the info on the Smoke generator deMort.
Looks a really useful piece of kit
 

New Threads

Forum statistics

Threads
124,583
Messages
1,446,532
Members
49,734
Latest member
11erCharlie
Back
Top