Jetdriver69

On my 82 5 speed after installing a new 928 MS aluminum rad and new AC condenser, the normally in the middle temp gauge is showing on the 2nd white line when warmed up.

IR gun shows about 185-190 F on the hose going into the rad and even under high revving in a garage with AC on, it never got above 200 F with the temp gauge reading about a needle width above 2nd white line.

Water pump is new, engine boiled out during recent rebuild, new over flow tank, new pressure cap, new Temp I and II sensors and connectors. Rad filled with Dex Cool and distiller water but no Water Wetter yet.

What exactly is the proper temp range for a fully warmed 4.5 L?

I am thinking it must be the gauge and can a OB temp gauge be adjusted from inside the pod like I saw on a write up for a newer 928?

Thanks

outbackgeorgia

My 87s4 runs just above the first white line. 928 MS radiator lowered it a little when maxed out summer with A/C on.

Dave

Jetdriver69

I read on another site that 185-195 F is the proper range before entering the radiator. About 20 F cooler coming out.

Is this about right? I couldn't find a temp range in the WSM.

jpitman2

On my 83 Euro, I have the electric fan switch in the top hose. The switch is a 98/93C unit (208F/199F), and this keeps the temps just under the second white line. IIRC S4 temp gauges are not the same calibration as the early car, but dont quote me. Thermostat is a stock 83C. When I had a 75C thermostat it tended to run on the first white mark, but it didnt run as sweetly as the higher setting.
jp 83 Euro S AT 55k

ROG100

Sounds like it is running perfectly - my 82 5 speed I am currently driving runs at the second white line. Yours was probably running too cool before.

Rich9928p

My '79 928 ran at the 2nd line and during the summer with the AC on would climb to near the red (but it didn't boil over) and using a temp gun didn't show excessive heat.

I ran a direct 12 power line via relay (ignition turning the relay on) and direct ground to the instrument pod. The volt meter now reads properly and the temperature gauge dropped about 1/3 lower in temp. This says to me that low voltage to the pod can cause higher that actual temperature reading to the gauge.

Dave928S

What !!! ... In that case George Layton had it wrong Roger, or you misquoted him ...

Your sig quote obviously should read .... Does it have the "Do It Yourself" Automatic transmission, or the superior "Fully Equipped by Porsche" Manual Transmission? George Layton March 2014

You're welcome ....