Contour Enthusiasts Group Archives Forums General Troubleshooting Temperature problems - need professional opinion

I tried this post before but was not solved.

Details:

'98 CSVT - 60,000 miles. Waterpump/fluid/thermostat replaced at 42k miles. ECT sensor replaced at 58k miles. High speed fan comes on when the AC is on.

Problem:

My car runs at different temperatures everyday. One day it runs in between the O and the R in NORMAL (which should be normal all the time), regardless of driving conditions, and other days it runs hotter (near the M and A) - during the exact same commute (25 miles one way). It seems like sometimes the high speed fan doesn't kick in until the engine is running excessively hot. Then the temp only cools off to the M.

I am thinking that it could be a bad sending unit or a bad resistor. I suppose that I could try a cooler t-stat after replacing those. Thoughts?

The high speed fan is only supposed to kick in if:

1. The Dual Pressure A/C switch tells it to.

2. The computer tells it to under when engine temperature exceeds high limit - around 215-220F.

Other than that, the fan usually uses the low speed operation.

The only way to determine what is going on in your cooling system is to measure its performance with an acurate thermometer. It might be that you have a guage or sending unit that is not consistent and that your cooling system is perfectly fine.

Only way to know for sure is to check it with an external device.

Steve

You can check your temperature sensor with a digital multimeter on the ohm setting. Typicaly the car should reach normal operating temp after running for 10 min. Which means the fan should come on. Normaly the fan would come on at around 100 degrees. I can't find the actuall temperature settings for when it is supposed to come on and off.
68 degrees ..........35.0 to 40.0 k-ohms
212 degrees ..........1.9 to 2.5 k-ohms
248 degrees ..........1.0 to 1.3 k-ohms

Hey i have a '98 csvt as well and i found the same problem. it will run between the "o" and the "r" while cruisng around but as soon as i hit traffice it mill go up and sit near the "n" and "a". it doesn't seem to go past that at all, i found turning the a/c on for a few minutes cools it right back down because the fan kicks in but i'm curious as to what others have to say or if anyone else has had this problem.

The low speed fan should kick on around 200F, not 100F.

Steve

I should have said celsius. The Haynes manual says the radiator fan is activated at 100 celsius for first stage and 103 celsius for second stage. Not sure what the conversion is for F to C.