Engine Temps

[Guest]

Morning,

I've been driving my 968 about for a week now, and I'm a bit concerned about the engine temperature. It doesn't seam to get high enough.

On a 30 minute journy, the needle rises so that it's only just above the bottom mark (block). Is this normal or is it too low?

I'm worried that either the thermostat may be stuck open, or the sensor that feeds the guage is under-reading.

Chris

 

[John H]

I would doubt if the calibration of these guages is very accurate, so comparing car to car probably won't tell you too much. A consistent reading is probably more important than the relative place on the dial.

That said, it does seem low, so your theories are entirely possible.

Just like my 924S before it, my 968 temperature guage moves around a lot, and if I get stuck in traffic it fairly rapidly rises, and then falls when the fan cuts in. This is quite unlike my modern VW Golf, where the needle remains utterly static no matter what.

Before investigating it further, I would be tempted to see what happens to the temp guage in traffic, or in hot weather (hey right!), if only to ensure that it is behaving as per normal for these cars. Let it idle for a few minutes, and the temp guage should rise, the fan cut in, and then it goes back down.

Running too cool will not be good for it, but it is a lot better than running too hot.

John H

John H

 

[Guest]

Mine is the same as your's Chris and like John the gauge rises in traffic until the fans cut in and then returns to the normal low running mark again soon after normal driving resumes. As far as i can acertain from several other forums, this seems to be pretty much the norm.

Del.

 

[Rob Sharp]

Mine too! Low reading most of the time, with a rise to about 2/3 of the scale before the fan cuts-in in traffic.

 

[Matt]

mine too. lovely and low on a long m/way run, but traffic sees it rising 'till the fan cuts in.
also warms up in minutes in the morning...

 

[wedgepilot]

I'm not sure if it's entirely relevant, but you might want to have a look at this thread from the 944 forum:

Engine temperature

 

[John H]

Very relevant, and thanks for pointing that out.

The 968 engine is a derivative of the 944 series, so if they tend to have a problem with failed thermostats, it is likely the 968 will too.

JH

 

[Guest]

My Sport is booked in for a service next week, and after reading that thread I've asked them to take a look at the thermostat.

I'll report back when I've got more news.

Would the engine running cold affect the fuel economy?

Chris

 

[wedgepilot]

In theory yes, because the hotter an engine runs, the more efficient it is. Don't know if the difference would be noticeable in 'real life' though. I'd be more concerned about engine wear due to cold running myself.

 

[Guest]

OK, I've just heard from the garage, they said that the thermostat is bust and needs to be replaced.

According to the diagram on the thread in the 944 forum, my car was running between 60 - 80 degrees, even after a 40 minute commute. The engineer at the garage has confirmed that this is too low, and that at these temps, the oil won't warm properly and that means increased engine wear.

When I've got the car back, I'll let you know how the temp gauge behaves.

Chris

 

[John H]

How big a job is it to replace just the thermostat?
I'm not sure I even know where it is on the engine.

JH

 

[wedgepilot]

If it's anything like the 944, the thermostat is in the water pump, and it's a real pain to change! It's held in by a fiddly snap ring which can corrode in place. One way around this is to hammer a screwdriver through the thermostat and pull it out in pieces! [&:]

 

[John H]

Thanks Alan, that sounds like a good reason to leave well alone then!

JH

 

[stephen belcher]

I have owned my 1994 968 sport since April this year. You may be interested to know, having similar problems with temp stat. I had Chapelgate Porsche Hampshire fit a new one after pronouncing it deceased. Cost of completed job £231 less Porsche club discount.

P.S. My 968 sport achieved runner up in its class at the Hampshire region concours this summer followed closely into 3rd place by a good friends 968 coupe. Guess you Can't keep a good car down!!!

 

[Malcolm Hickman]

Nice picture EGO size of photo

 

[stephen belcher]

Ooopps Well first attempts always the best. Engineer i am, computer whizz i'm not. But like the car I will get better as time goes on

 

[John H]

Stephen and Malcolm,

Welcome on board and nice to see another two new faces joining in. Keep it coming!

John H (968 Moderator)

 

[Guest]

I picked my car up from the garage last night, and I can already report that with the new thermostat installed, the engine is running at better temp. (needle in the middle section of the gauge).

I'm much happier to give my car some beans now that I know the oil's up to temperature and working properly.

Infact I can feel a lunchtime blast coming on...

[]

Chris

 

[Marky Boy]

Hi my car had the water pump replaced in Oct. The water pump went and the engine overheated and blew the head gasket. This was before i bought the car but i have a recipt for a porsche specialst that sorted it. It has a new thermostat put on it when this was done and it still looks like it sits low. Just above the lower thin line when at speed. And upper line when hot. Its really cold outside so i reakon that may be helping keep it cool.

Surely an aluminium engine should run cooler to prevent warping and also with the increased heat disipation. Or am I just being stupid.