what should the resistance on the coolant temp sensor be? my gauge is reading pretty low, thinking the sender is bad.
i measured about 8-9kohms at around 30degC. dropped to about 3kohms when i put it in boiling water. that seems high to me. can anyone tell me what the right resistances should be?
oh yah, 90 sunbird 2.0L.
First is the thermostat the original?If so it's probably stuck open causing the temps to be either hot or to cold.That's always the first culprit and not the sender.Do you a temp gauge or a dummy light for high temp?IF u are going to do a cooling flush you should install a new thermostat,temp sender and both upper and lower hoses due to age.You should also consider the water pump replacement as well even if its not the problem u will have the system drained and if its a 2.0 its real easy to change out.Please post what engine u have as to make replying back a little easier so we can be specific in detail as what u may need to do.
hoses and thermostat are okay, checked them out. the car has a gauge, not idiot light, and it's the sender im worried about, because the resistance does seem to be too high. AFAIK GM used pretty much the same coolant temp sensor in all applications from the mid 80s thru mid 90s, and the resistance should be much lower than what i see on mine.
You should just replace the sensor, its only 9$ at Advanced or Auto Zone.
i just bought a new one anyway. the new one reads about 2kohms @ 23degC, where the old one read almost 12kohms. strange... not sure how the old one broke, but that appears to have been the prob. cured my rich condition too.
Well for ur info the coolant temp affects the air/fuel mixture and causes the ecm to tell the tbi to increase the fuel due to lower coolant temps.THose switches can go anytime,age is mostly the culprit and remeber it is a electrical part and it can be either last forever or die if the wind blows.
weird thing was that the old one still "appeared" to work. i measured 2kohms in bioling water, 13kohms at around 30degc, and like 70kohms when i put it in the freezer. fairly reasonable ranges for an NTC thermistor, not a dead open or short like you might expect from a dead sensor. but the new one definitely read differently. starts up a bit easier now, and no more gas smell from the richness.
