Need the ECU voltage reading for the water thermosensor confirmed. S5!
05-13-03, 12:50 AM
#1
Need the ECU voltage reading for the water thermosensor confirmed. S5!
kay,
Got an S5 vert in the garage with idling problems. Fixed a few minor probs that have made the idle slightly better, but the water thermo-sensor reading seems to be off.
At operating temps I was getting a range of .7-.8 VDC. According to the FSM, thats not right, should be in excess of 2.4 VDC. Can anyone confirm this?
Thanks in advance!
jarrett
Got an S5 vert in the garage with idling problems. Fixed a few minor probs that have made the idle slightly better, but the water thermo-sensor reading seems to be off.
At operating temps I was getting a range of .7-.8 VDC. According to the FSM, thats not right, should be in excess of 2.4 VDC. Can anyone confirm this?
Thanks in advance!
jarrett
05-13-03, 10:00 AM
#2
I was about to go for a drive and tell you, but I just checked the FSM and it says that with the engine hot at idle, readings should be 0.3V - 1.0V. That would make your reading OK. It says it should be 2.4V with the water temp at 20 C, or 68 F.
05-13-03, 12:47 PM
#3
HAILERS
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Same sensor on a series four, I do believe. When it reads 0.50 volts the water temp is approx 185 degrees. the higher the reading....the cooler the water.
Each morning I'll see somewhere above 2 volts, til it warms up, then approx 0.50
And if you watch the meter when the car is warmed up, and say you see around 0.50 or so, then turn the headlights on and or air conditioner, and then the voltage immediatley goes up a couple of points like to 0.54........the car has a grounding issure somewhere. Not in the ground for the water thermo sensor, but elsewhare.
Each morning I'll see somewhere above 2 volts, til it warms up, then approx 0.50
And if you watch the meter when the car is warmed up, and say you see around 0.50 or so, then turn the headlights on and or air conditioner, and then the voltage immediatley goes up a couple of points like to 0.54........the car has a grounding issure somewhere. Not in the ground for the water thermo sensor, but elsewhare.
Last edited by HAILERS; 05-13-03 at 12:50 PM.
05-13-03, 06:13 PM
#6
HAILERS
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The online manual for 89-91 reads like J-Rat wrote. It's not really any different than the quote out of the 91fsm except when they wrote Idle(engine cold) and give you a figure. Makes no sense to me especially with such a large range for the reading to be.
So, what does your sensor read with the car warmed up?
So, what does your sensor read with the car warmed up?
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05-13-03, 11:08 PM
#8
HAILERS
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Seems like a real cool engine you got there bubba.
On page FI-83 of the online manual, there is a chart showing what the resistance of the sensor is supposed to be when at certain temps. Such as when its in a pail of water that is 176 degrees in temp, the resistance should be 0.3K ohms to 0.1K ohms.
Both my turboii are sitting around 0.50 volts when warmed up and just a sitting there in the driveway. They're not nearly as cool a car as yours. Could be both my cars are defective and yours is the right one.
On page FI-83 of the online manual, there is a chart showing what the resistance of the sensor is supposed to be when at certain temps. Such as when its in a pail of water that is 176 degrees in temp, the resistance should be 0.3K ohms to 0.1K ohms.
Both my turboii are sitting around 0.50 volts when warmed up and just a sitting there in the driveway. They're not nearly as cool a car as yours. Could be both my cars are defective and yours is the right one.
Last edited by HAILERS; 05-13-03 at 11:20 PM.
05-15-03, 03:03 AM
#12
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Oh. I went to sleep after my last post, something I should have done again an hour ago.
I must be misreading this post. WAter thermo sensor. Back of the water pump housing. Used by the ECU only. Not the water temp gauge. I know you know that. I'm just reading this wrong.
Seems you could have just pulled a water thermo sensor out of one of your many cars.
I don't think the water thermo sensor has much of anything to do with your engine overheating. I must be misreading posts again. Water temp gauge gets its reading from the water temp switch near the oil filter assy. And I know you know that. Gotta be me misunderstanding something.
If your not spilling water or puking it in the overflow....how about swaping radiators b/t cars????? Thermostat...nah, you'd have done that already. Radiator cap. Nah you'd a done that, and anyway its not puking water or you'd a said so.
Oooops. Don't series five cars water temp gauges read half way as a normal thing. Just read that recently on this site.
More sleep needed here. Later. Ignore the above, just let us know how things turn out.
P.S. There is nothing quite like a 87na, now turboii. The n/t would huff and puff and gasp to get to the 125-130 mph. I just hit 120 going home and it just wanted to go faster and faster.
I must be misreading this post. WAter thermo sensor. Back of the water pump housing. Used by the ECU only. Not the water temp gauge. I know you know that. I'm just reading this wrong.
Seems you could have just pulled a water thermo sensor out of one of your many cars.
I don't think the water thermo sensor has much of anything to do with your engine overheating. I must be misreading posts again. Water temp gauge gets its reading from the water temp switch near the oil filter assy. And I know you know that. Gotta be me misunderstanding something.
If your not spilling water or puking it in the overflow....how about swaping radiators b/t cars????? Thermostat...nah, you'd have done that already. Radiator cap. Nah you'd a done that, and anyway its not puking water or you'd a said so.
Oooops. Don't series five cars water temp gauges read half way as a normal thing. Just read that recently on this site.
More sleep needed here. Later. Ignore the above, just let us know how things turn out.
P.S. There is nothing quite like a 87na, now turboii. The n/t would huff and puff and gasp to get to the 125-130 mph. I just hit 120 going home and it just wanted to go faster and faster.
05-15-03, 03:22 AM
#13
Originally posted by HAILERS
I must be misreading this post. WAter thermo sensor. Back of the water pump housing. Used by the ECU only. Not the water temp gauge. I know you know that. I'm just reading this wrong.
I must be misreading this post. WAter thermo sensor. Back of the water pump housing. Used by the ECU only. Not the water temp gauge. I know you know that. I'm just reading this wrong.
You got it right...Thermosensor, back of water pump.
Seems you could have just pulled a water thermo sensor out of one of your many cars.
Its an S5 vert...I probably could have, but I am not going to disable a perfectly good FC for troubleshooting. The multimeter tells ALL!!!
I don't think the water thermo sensor has much of anything to do with your engine overheating. I must be misreading posts again. Water temp gauge gets its reading from the water temp switch near the oil filter assy. And I know you know that. Gotta be me misunderstanding something.
Car isnt overheating...Just verifying some ECU readings. The car has MAD idle problems. Its not my car, I am troubleshooting it for a friend.
Its all good, the new sensor is on the way. Compression checks, I have repaired some other things. Gonna send the injectors to be cleaned. Hopefully I can get to the bottom of this.
Jarrett
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