Porsche Enthusiasts Club Forum

Hi all,

Thought I'd stick this online to reinforce my suspicions!?

My 944 on a commute to work over 10 miles never gets out of the lower box on the temp gauge. The fan isn't currently working so in traffic that climbs up to 3/4 before I start moving again! Heating seems to work when warmed up.

To me, this sounds like the thermostat is stuck open - your thoughts? Waiting for ammeter to test relays etc for the fan.

Will

I use mine every day on a 7 mile trip so will make a note tomorrow.
Heater is working within 2 miles but I doubt the engine is even near 1/2 temp.

I get about 28 mpg and that is the clincher because a stuck thermo will dramatically ruin the consumption to 20 mpg or so.

It'd be interesting to know.

I did test drive a few, but am no means an expert with regards to the cars and the way that they run. I know the fan doesnt work, which will be sorted soon enough, but wasn't sure if the thermostat would be making it run cool and warm up slowly (or do they run cool?)

MPG was around 25mpg on the first tank, but it's the first tank I've run through so I haven't been driving for economy! It's also got Cup 1 wheels, so not sure if that would effect economy, judging by the speedo it does gear it up a bit!

Will

Well my trip to work was monitored and this is what happened.
My trip is all in the country with no traffic or jams and I do approx 30 mph for 2 miles and 40-50 thereafter.

2 miles no gauge change and heater feeble.
3 miles heater comes on well and gauge near the first mark.
4miles just a fraction shy of first gauge mark where it stayed.

My sons 16 valve Escort dropped from 35 mpg to 25 when his thermo stuck a few years ago.

My car is a 2.5 Lux and runs 16" S2 wheels.

Good luck with sorting it out.
Jon

Unlike a modern car the gauge will not stick in the middle and stay there. It does vary quite a lot and this is normal. Normal operating temperature is at roughly 1/3 and the fan kicks in at 2/3. This applies to square and oval dash cars.

Secondly these cars are now quite old. Assmuming yours is an oval dash model there are some bits inside the binnacle known as "rugby balls" that corrode and require cleaning (Google it). When these are dirty some of the gauges do not read correctly due to increased resistance. On mine this affects the fuel and temperature gauges and on the to do list.

Hope this helps

Agree with the comments about gauge fluctuation etc. My car is exact same.

Will say that I have recent thermostats, well 2/3 years old, in my turbo and I get warmish air through the vents after a few hundred yards! After a mile it's at full heat. I can feel some heat before the temp needle starts to move at all!

I'm suspecting slight air locks for you guys if it takes an age to heat up.

Stuart

One thing worth thinking about with these is that the thermostat is mounted in a lightweight rubber ring and a circlip, if the thermostat gets to over about 8 years old without being changed along with the new rubber seal the seal often breaks and goes AWOL... This allows coolant to get past the thermostat and bypass it, often meaning the car never gets up to temp.

A 944 oval dash should run a bit over the one third mark on the guage, a square dash should run at the half way point.

With both an oval and square dash the fan or fans should come on at between the half way point and the two thirds mark.

Interestingly aftermarket thermostats sold by places like Porscheshop, EuroCarParts and Design911, unless made by the correct OEM manufacturer (Walter or Walther from memory) run cooler, to the point on an oval dash of often running on or just under the one third mark, which tends to make the car not only run colder but burn more fuel.

The genuine/propper OEM thermostat is also a much more heavily engineered item than the aftermarket ones often sold as OEM.

I would only fit the proper OEM or genuine one, it is such a pain to get to and change, it is not worth saving a couple of pounds on buying the cheaper alternative.

Hi,

Thanks for that, very interesting! I've just ordered a new thermostat, as well as a new front fan as I'm pretty convinced that it's dead. I've only got 19mpg out of the last tank, so it needs sorting!

Will update when I've managed to sort it!

Will