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Went for a nice long drive today with my 7yo boy. Aside from the squelching FL Gulf Coadt heat (roughly 93 degrees with some nice humidity) and the inop AC , the drive was pretty good. The round trip was roughly 50 miles, mostly on I75 and between 70-80mph. Being a little paranoid, I kept a close eye on the temp gauge which, by the time I returned home, was concerning - right at the red line thresholds.
Understanding the atmospheric temperature wasn't helping, is this concerning? Where does your gauge typically sit once properly warmed up: exactly at the unlabeled 190ish mark, between 170 and 210? Should I replace the coolant and thermostat? Please see the below photo taken while sitting at a light.
First, clean the pin connections on the Temp-I sender (gauge) on the left-side of the water bridge.
Second, make sure that your gauge accurately reflects engine core temperature.
There are at least two ways:
- Bosch Hammer or Theo Tool reading temperature from the Temp-II sensor.
- Contact thermometer on the base of the Temp-II sender on the right-side of the water bridge.
- You can also use an IR thermometer, but I prefer a contact thermometer for this process.
Check the above-measured temp against your gauge at at least two temps: cold or warming-up and warm or 'hot.'
In hot ambient conditions (humid summer Florida daytime) at speed I would expect 195°F at the Temp-II sensor. In extreme conditions (100°F and slow traffic) with the A/C on 205° and just about to touch the red.
If you decide that you are running 'too hot' then:
- make sure both electric fans operate
- blow/clean any accumulation of crud from the radiator matrix.
Mine is right before or on the second white line, 89-90 degree C (192 - 194F) when the car is at normal operation temperature.
I checked today with a IR gun on the WB near and on both sensors, I and II, but readings are all over the place! It changes a lot moving just an inch.
One year old WP and coolant, two years old 83 degree thermostat.
First, clean the pin connections on the Temp-I sender (gauge) on the left-side of the water bridge.
I thought the water temp gauge sender is the one on the right of the water bridge when looking at it from the front of the car with the hood open. Am I mistaken?
I thought the water temp gauge sender is the one on the right of the water bridge when looking at it from the front of the car with the hood open. Am I mistaken?
Great recommendations by everyone, including the PMs, def the flaps as the highway driving should have helped bring the temps down. In addition to checking my records for any service history to the cooling system, I'll def check the flaps fuse, test the coolant, and the various other bits.
I had the same problem even after tstat, tstat seals and reservoir cap . I pulled the radiator and found it leaking and partially plugged. I got a new radiator from Roger and temp runs just as Bertrand has mentioned before.
I thought the water temp gauge sender is the one on the right of the water bridge when looking at it from the front of the car with the hood open. Am I mistaken?
Not really. "Left" and "Right" can be confusing when dealing with the different perspectives.
I was taught that they are as viewed from the driver's seat.
So "left" is anything on the driver's side. Which is where the temp sender is.
And to Worf's comment about cleaning the pins: While cleaning the connections is never a bad idea, the temp gauge reads decreasing resistance as higher temp. So if the connections are dirty and adding resistance to the circuit, that would give a lower temp reading than actual, not higher.
I fully agree with the idea of getting actual temp readings off of the engine and radiator hoses. The sender may be off, the gauge may be off. Or it may be running hot.
I thought the water temp gauge sender is the one on the right of the water bridge when looking at it from the front of the car with the hood open. Am I mistaken?
In that context no, but ...
Originally Posted by Wisconsin Joe
Not really. "Left" and "Right" can be confusing when dealing with the different perspectives.
I was taught that they are as viewed from the driver's seat.
So "left" is anything on the driver's side. Which is where the temp sender is.
This is %99.9 correct. The best nomenclature is in the context of the vehicle's normal forward travel without reference to the driver's position or facing direction.
Originally Posted by SwayBar
Also, I thought just the GT's have the numerals on its temp gauge like this car does, but the OP states it's an S4. Am I wrong again?
EDIT - I see on the dash it's an automatic and can't be a GT.
The gauge with numerals began - as far as I know - with the digital cluster. To date I have not seen a digital cluster without numerals or an 'analog' cluster with numerals.
So... MY '89.
Originally Posted by Wisconsin Joe
And to Worf's comment about cleaning the pins: While cleaning the connections is never a bad idea, the temp gauge reads decreasing resistance as higher temp. So if the connections are dirty and adding resistance to the circuit, that would give a lower temp reading than actual, not higher.
And thus the OP's problem might be worse. There is at least one more-obscure failure mode too.
The point is to make sure that the measurement device being used (the gauge) is trustworthy.
06-24-2018, 12:19 AM
89s4 with high temp. Thermostat issue?
, the drive was pretty good. The round trip was roughly 50 miles, mostly on I75 and between 70-80mph. Being a little paranoid, I kept a close eye on the temp gauge which, by the time I returned home, was concerning - right at the red line thresholds.
