1992 500e fails to get hot
 

I have a 1992 500e w/ 90 K miles om the speedo. The temp gauge only reaches 60 degrees C and will get slightly higher when driven hard. I am seeing a temp (infrared thermometer) on the hoses at the water pump at about the same temp as what the gauge reads at about 60-65 C. I installed a new thermo and the same problem exists. I would like to get this addressed.
The car can idle for ever and never get hot and the fans never come on unless the a/c is turned on. I cannot believe that an upgraded fan clutch could make the car never warm up even when sitting still idling for an hour. I know that most 500 owners would love this problem but I need heat to go fast

I also noticed that pressure never builds up in the system and will be installing a new car and pressure testing the system in the next few days. Than God that I have a crotch rocket to fill in my need for speed for the time being.

Info that may help is that the thermo clutch was replaced with a heavier duty unit and the thermostat and radiator were replaced about 2 years ago also. The coolant temp issue has been about the same since that time but the vehicle has been driven only a few times since that time. I want to get it out this summer and drive it but it needs to be in the 90's to be right.

Jeff AKA Moose
92 500E
73,74,75 240Z,260Z and 280z 2+2

The fan clutch shouldn't have any effect on the bottom end reading on the coolant temp.

It sounds as though the thermostat you installed may be defective. You can test it in a pot of boiling water with a thermometer. It should start to open at 87C and be close to fully open at 100C, when the water boils.

replaced already
 

I invested the 4$0 and installed a new thermostat and the problem is still the same. I do not have a thermometer to test the thermo but it did open when tested but not sure of temps. It sure acts like it is stuck open but it's not

moose

re thermostat
 

Having the 119 engine, I had the same thing happen a while back.
Changed the thermostat and no difference. I ended up just changing the sensor and now it reads correctly. My fans don't really turn on that often but that is a different sensor anyway.
I run this car hard most of the time. when its warmer out it turns on but still not often because then the ac turns it on.

PS i changed mine twice because two different ones were available.
Your stll futher a head then me.

Joe

lack of heat
 

The sensor you are talking about is located directly behind the water pump on top of the intake? It has a single electrical contact that connects over a post on the top of it? I replaced it once and the needle pegged, reinstalled old one and it was fine. Did yours have a low reading on the dash? Mine is reading about 60C on the dash and using an infared thermometer it reads about the same.

any thoughts on the sensor being the cause?

Jeff

Could be the temp. sending unit on the gauge. About $10. Check out this thread
http://www.500ecstasy.com/forums/showthread.php?t=2753&highlight=heat

Replace your sender, it's a cheap part and an easy fix. Re-do your thermostat at the same time, just to be sure it's all known good.

Cheers,
Gerry

fixed basic volt ohm reading for coolant sensor
 

I replaced the coolant sensor after obtaining the following data. Ohm are dead on but the voltages are very close. After replacing a $20 sensor the coolant fans come on properly and the gauge reads about 90C at idle. The car runs much better and owner has a major case of "perma-grin" again. Thanks for the input.

0C=5900 4.25V
10C=3700 3.95V
20C=2500 3.60V
30C =1700 3.15V
40C=1170 2.65V
50C=830 2.30V
60C= 600 1.93V
70C=435 1.50V
80C=325 1.22V
90C=245 1.0V
100C=185 .81V


<-- wants 6.5 biturbo for my 500E