Nicholbry

I am new to 928 ownership and I have had a thermostat replacement (83 degree) recently. It hasn't seemed to affect the operating temperature, however. I was just wondering if this was normal: In southern Mississippi/Louisiana driving my temp gauge is reading just below the 3/4 mark. In stop/go traffic, my gauge creeps up to the 3/4 line. It hasn't moved beyond it, however. Is this normal operating temperature for the 928 S4? My other cars have not ran this warm in the past and I had nothing other than that to compare it to.

Thanks,

ROG100

Sounds normal as long as it does not go higher

davek9

Try a can of Water Wetter that will bring it down a bit and give you a larger margin, you should have someone do a temp check on it.
IMHO some gauges seem read higher than others, mine does not go much beyond 1/4 and only did mid to 3/4 before I replaced my coolant and changed the t-stat.
Wouldn't hurt to know exactly what it is, right?

Dave K9

0utlier

For a 1990 s4 that is normal. It is a little disconcerting to see how little room is left before the red, but almost 3/4 is normal. Mississippi ehh? I was born and raised in Jackson. RngTrtl is in Jackson and Johan928 is in Ocean Springs.

Cliff Ruckstuhl

My S4 does the same thing and the stat has been changed

Cliff S4 Murf # 44

Nicholbry

I'm glad to hear that my temp is normal. I was told so by a mechanic who specializes in Merc & BMW who did some work on my car, but since he saw very few 928's I thought it prudent to ask the experts who own them.

Thanks guys for being so helpful!

Fogey1

That sounds fine, but ...
You're trusting the temp gauge, which might be fine, but it is an electrical device on a 928. ;-)

This is a perfect use for a non-contact thermometer.

Kevin Michael

Cliff, what did it read before the SC install?

Bill Ball

The lower temp T-stat only affects coolant temperature on cool days. It cannot affect cooling capacity. Once it closes off the bypass, the capacity of the cooling system to remove heat is the same. So, on hot days, with high thermal load, you get to the same temp.

Mrmerlin

get a IR gun and take temp readings when the car is warm see what the coolant temps are

IcemanG17

It sounds normal......the temp gauges in 928's are all over the place....some read low (if your lucky) others read high (common) you just need to establish a baseline for your car.....in general the lines read somewhere around these temps....170 for the 1st white line.....then 195 or 210 (depending on who you ask) for the 2nd white line.....I believe its 170-195-210?? (for start of redzone).....but I have taken IR readings at the waterpump on hot days when the gauge reads a touch over 1/2 and it shows 190+ degrees...so I dunno

Mine likes to run around the 1st white line.....up to 1/2 on hot days with the A/C on.....& right at the 2nd line when pushed hard (100+ a/c full blast, climbing hills in traffic...or at the track in hot weather)....

if you look in the WSM you will see the cooling fans operation "map" that shows how the fans kick on at around 170 degrees (4 volts) and progressively increase to 12 volts at around 195-200 degrees (somewhere around there I can't remember)

dr bob

What Bill said, plus the flap and fan electronics will work to keep the temp up in the 90-95C range minimum. The flaps will pinch off airflow if the engine is too cool, and the fans are variable-speed units that won't help airflow until the coolant is warm enough. While it's possible to "fool" the two controllers so the car operates cooler on cool days, it really does nothing for total cooling capacity on hot days. Amazingly, thse hot days are when most owners start to get nervous about the gauge readings.

heinrich

My cars never rise above the 3/4 line, and all my healthy cars over the years have run about the nine-o'-clock position normally, with hot traffic driving getting up to 3/4. If you did replace the thermostat to a 72deg one (Mr Bailey strongly recommends against it) like I did, then you may find that your avg temp drops. I had a car that had a bad thermostat which definitely would get up higher in traffic, but it had only one opportunity before I replaace the therm as well as temp switch in the rad. Fixed it perfectly.

heinrich

Bob I found that the flaps actually caused overheating at 155mph and above, because they were closed. I removed them and had no more issues.

SharkSkin

H, how can I get my temp gauge to read at the 9:00 position?