reno928s

I bet the cooler thermostat will do the trick. In regards to the spark plugs, what heat range plugs did you install? Reno

reno928s

I forgot to mention when installing the thermostat make sure the bleeder hole is at the top. Reno

ErnestSw

I've never checked my spark plugs. I'll do it tomorrow.

PeteS

I once had a Mustang that started to run hotter than normal just before the fuel pump went out. Apparently the dying fuel pump was causing a lean condition which increased the temperature. I assume something like a plugged fuel filter could do the same thing.

I've got the stock radiator in my S4, WaterWetter, and the lower temperature thermostat. I've checked my dash temperature gauge against an infrared thermometer reading and found it to be basically accurate. The gauge needle usually reads just above, but still barely touching the lower white line of the gauge with the engine fully warmed up. With the A/C on, driving the car hard, and ambient temperatures in the upper 90's, the gauge might get to a little above mid way between the two white lines, but never fully on the top white line.

WallyP

You guys keep on acting as if the temp gauge in a 928 is a precision instrument that reads the same in each of your cars...

928FIXER

Have you had the radiator cap pressure checked???Lower then sped'ed
pressure holding lowers the bloiling point of the cooling system and makes the car run hotter

Chris

Like others mentioned have you tired putting the stock chips back in ?? Autothority chips lean the mixture and advance the timing.

While this might work fine for majority of 928's its conceivable that these settings might be marginal on others due to a whole range of conditions particular to your car.

Worth a go, bet that gets rid of the pinging.

Chris

Doug Hillary

Hi,

ErnestSw - you have a infra-red temp unit i believe. Perhaps you should measure the temps on the top rear of each valve cover and at the electrical connection above the point where the top hose leaves the engine

Compare these with the ones I provided earlier. These points have given the most consistent temperatures during my testing

The front of the thermostat housing where the bottom hose attaches too would be a good comparison point

And listen to what WallyP has to say!

Regards

ErnestSw

Wally,
Notwithstanding the questionable accuracy of the dash gauge, mine correlates with the diagnostic plug readings. I'm ASSUMING that the raw readings are from the thermistor and reflect what the sensor is seeing, not what the gauge is reading.
928Fixer,
I JUST replaced the reservoir cap and it made no difference.
Chris,
The stock chips were replaced by a PO and didn't come with the car. They're on my list as a possibility. Does anyone know whether the GT chips are the same as the S4 chips?
Doug,
Thanks for the tip.
Ernie

Nathan Valles

Has your car ever overheated or is this just a case of preventative maintenance? If the car has never overheated.... get a infrared temp gauge or find someone who has one, and shoot the engine and radiator. Turn the heater on and shoot all the heater hoses and connections you can find too. Do it on a cold morning and write it all down, then do it again on a hot day after a hard run.

Make sure you have a problem first before you spend more time and money chasing something that might not be a problem. At least then you will KNOW if the temp monitoring system is reading correctly.

At least that's my 2 cents worth.

ErnestSw

As I suspected, the 75 degree thermostat makes no difference. The temperatures are as follows:
Ambient 95F
Thermostat housing 197F 92C
Rear right cam cover 229F 109C
Rear left cam cover 204F 96C
Thermistor (direct reading) 210F 99C

If the "normal" gauge reading represents approx. 187F, I'm running about 23F or about 11C above normal.

mark kibort

finally changed my water pump that failed and all is great with a stock radiator. ran in 95 degree temps at speed GT, full throttle for 50min and temp was still in the middle. during any of the practices, I was dead even in the middle. blead the system by burping it, new thermostat with 1/8 pin hole on top. water wetter, 1/2 quart of antifreeze and distilled water.

check your hoses when over heating, if the lower one is cold, your thermosta is stuck. check the face of the radiator. see if the entire radiator is hot. (it should be under normal operating conditions) if it is cold, then you have a bad water pump, stuck thermostat or air in the system.

both mark anderson and I have stock radiators and the engines run cool in racing environments with both 335rear wheel hp and 470rear wheel hp.
so, if you have an even better radiator and you are showing hot readings, you probably have other issues. my 79 had no problems day to day driving, but racing on a 100degree day pushed it too hard. with the devek radiator, the cooling issues were improved. could have been a clogged radiator and for the cost of the devek radiator, it was the best replacement solution and it does work better cause it is bigger!!!

mk

T_MaX

"1/2 quart of antifreeze and distilled water"

This maybe the one of big differences!

What is your mix ratio Ernest?

Mark, are your rad.'s new or refurbished?

Are you running any cooler lines though your rads?

ErnestSw

To be perfectly honest I haven't got the faintest clue what my mixture is. I've added and subtracted so many times I've lost track. It's orange!

T_MaX

I'm going to dump mine tonight and give Marks mix a try.