Coolant/oil not coming up to temperature

[1Squadron]

Hi,

A few weeks back I drove the car on a warm day for 30 minutes and the oil never rose above 70deg. I didn't think to look at coolant that day.

I since had a drive last weekend where there was no issue...

Then, yesterday I drove for 45 minutes and had the same problem. Looked at coolant and while moving, it was reluctant to go over 60deg. If I idled at a standstill for a few minutes, coolant started to come up around 80deg but as soon as I got moving again, it came back down. I noticed that my coolant temp gauge was a little erratic. Bumping around a little, wiggling a few degrees here and there. No idea if this is normal.

Thermostat? I went to Porsche Portsmouth after the first one. Their diagnostic showed a "historical thermostat fault code" but no issue evident.

Frustrating as I can't drive the thing properly!

Thanks!

 

[1Squadron]

Sorry - I neglected to mention that the car is a 2012 (997) Turbo S.

 

[deMort]

I'm pretty sure these have a gearbox oil cooler fitted .. this has an electric valve that closes the cooler for warm up then opens as needed to cool the oil .

The valve fails and the cooler is open all the time .. I would have the car cold and on the ramp .. look on the n/s for a grey valve with vacuum pipes .. next to this is the actual switching valve .. it will be in the down position for open .. start the car from cold and it should raise .. if it doesn't then this is the area of concern .

Basically the car is over cooling .. stationary and it will hit temps in 20 mins .. drive it and both coolant and oil will drop .

 

[1Squadron]

Thank you kindly, deMort. Sadly I am too far from your place of work to let you or one of your colleagues have a look. I shall have to take your guidance to Porsche Portsmouth to point them in a logical direction. Loving the fact there is actually something physical that can be looked for.

I will probably come your way for my service around Christmas time. Tempted to also ask you to do the inlet pressurising thing (per a great post somewhere on here where the chap used some plumbing fittings, a foot pump and leak detector spray) as I am only seeing 0.9 to 1 bar in all modes. Anyway. I digress..

Thanks again!

I'm pretty sure these have a gearbox oil cooler fitted .. this has an electric valve that closes the cooler for warm up then opens as needed to cool the oil .

The valve fails and the cooler is open all the time .. I would have the car cold and on the ramp .. look on the n/s for a grey valve with vacuum pipes .. next to this is the actual switching valve .. it will be in the down position for open .. start the car from cold and it should raise .. if it doesn't then this is the area of concern .

Basically the car is over cooling .. stationary and it will hit temps in 20 mins .. drive it and both coolant and oil will drop .

 

[deMort]

From memory you only get above 1.0 bar in over rev boost .. a 10 second burst of 1.1 bar .. need to look it up to confirm but what you have seems normal .

1 bar is 14 psi .. if you think 2 bar is the pressure a tyre is inflated to and how hard that is you get an idea of the pressures .

We would use a smoke machine then an airline to increase the intercooler pressure .. any leaks at that point will be obvious .

I have to mention .. i don't represent my garage .. i'm just a mechanic there but you are more than welcome to come along , have a waiting service and say hi ... i'll show you around your car as well if wanted .

If you want me to do the actual work then please say when booking the car in .. i need to be allocated to the job basically otherwise i'll be listed for other work .

 

[jonno_]

Turbo overboost should be to 1.2 bar for a short time.

If your car won't boost to that level there are a few common issues to check for, Inc. holed intercooler(s), worn / damaged turbo(s), soiled MAF, poorly seated Y pipe.

Just hope its not the turbos.....

 

[1Squadron]

Interesting subject. I've learnt about the "little arrow" which shows when overboost is active. Not had an opportunity to look for it yet, due to the over-cooling issue. Currently having lunch in the Village Hotel while the car cools off over the road at Porsche Portsmouth (Inchcape) ready for its 13.30 slot.

Assuming the overboost thing is the same on a Turbo S as a normal Turbo. I had actually thought the S came with more power than a ormal T but maybe I am mistaken.

I am relatively confident it's not the turbos.

Ian - thank you and of course, I understand your comments and the need to make them. I will come yoir way for my major service bit it's too far for me at the moment due to a very busy life, just to put it on a ramp and have a look. Hopefully the guys here at Inchcape are capable of following your very specific instructions!

 

[deMort]

I did some digging on boost info for your car .. unfortunately i have info for a 2010 Turbo but not an S .. hence i'm unsure if they boost any higher.

From reading this though it seems the max is 1.0 bar due to other enhancements in the mid range .. it doesn't mention flat out or any other conditions to exceed this though so i'm not 100% sure .

If people are sure it should be 1.2 bar then you are slightly down but mid range it seems in the ballpark .

Either way a smoke test of the intercoolers / manifold with some extra pressure added will show a leak .

 

[1Squadron]

Thank you. Interesting that it seems to be saying that the 997 runs lower boost than the 996 due to some design enhancements.

Great documents overall. I could happily eat whole manuals if I had the time.

They didn't identify any issue today at Porsche centre Portsmouth. Basically I think whatever it is, it's intermittent. I drove the car away frim there in a fully warmed up state. It stayed that way for a further 15 or so minutes of driving. Some spirited and some cruising around 70. Then it suddenly decided to over-cool again, with temps diving to 65/70deg oil and 60deg coolant while cruising around 70, in the space if about a minute. Spirited driving (the sort that would normally see the car over 90deg for oil) made no impact on temps.

I stopped for five or ten minutes to call the guys in Portsmouth again, with engine idling. During which time it came back up to temps. They weren't able to see me as too late in the day.

I need to plan some morning weekday drives, to have the opportunity to drive it straight there if the issue pops up again.

 

[1Squadron]

Just to add - in the time that I did have a suitably warm engine and the opportunity to go WOT, I did not notice the little iverboost arrow showing up. I will try again once the current issue is sorted. I think I saw 0.9 bar today. Might see if I can change the display to PSI for a more granular reading.

 

[jonno_]

I expect the 997 from factory will run lower boost them 996 because the 997 Turbos are variable geometry :thumb:

 

[Chumbaside]

I'm pretty sure these have a gearbox oil cooler fitted .. this has an electric valve that closes the cooler for warm up then opens as needed to cool the oil .

The valve fails and the cooler is open all the time .. I would have the car cold and on the ramp .. look on the n/s for a grey valve with vacuum pipes .. next to this is the actual switching valve .. it will be in the down position for open .. start the car from cold and it should raise .. if it doesn't then this is the area of concern .

Basically the car is over cooling .. stationary and it will hit temps in 20 mins .. drive it and both coolant and oil will drop .

+1 for the same issue! 2008 997.1 Turbo Tip, if I set off from cold and get straight on the motorway, the oil never gets above 65-70 degrees and the car throws the 'Failure Indicator' error. As soon as I'm off the motorway / in traffic, the temps start to come up and the error resolves itself. Worse on cold mornings which I assume is increasing the effect of the cooler being 'open' all the time.

Replacing the water temp sensor made no difference so have a bypass valve on it's way to me (based on the great advice on this forum). Hopefully it's easy to fit!

Cheers,

Mark

 

[deMort]

Fingers crossed for you that this is the issue .. i can say i replaced this valve on a car a week ago for a coolant issue .. no gauge and red light flashing on that one .

There is a vacuum pipe and the actual mechanical switching valve so a couple of items that could be at fault ..

In my experience .. it's always the electric switching valve that fails .