Possible bad temp sensor?
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Possible bad temp sensor?
So, when the temp gauge moves to the middle of the scale the coolant temp should be 90C, correct? And, 90C is the operating temp at which ECU uses leaner fuel map(s), right?
Block 001 shows temp at 81C but the temp gauge sits in the middle. My heater works fine and starts blowing hot air quickly after startup, so I don't think this is a thermostat issue. Rather, it looks to me that ECU is being told incorrectly that the enginge is cooler than it is (maybe due to a lazy temp sensor?).
Which sensor does VAG-COM get its reading from?
And, how do you explain the difference in reading (temp gauge vs. Block 001)?
P.S.: Continuing STFA and just read that there are two sensors: one feeds the temp gauge and AC equipment; another one feeds the ECU. So, my guess is that the one that feeds the ECU is bad and it is located on the back of the engine block
Correct?
Block 001 shows temp at 81C but the temp gauge sits in the middle. My heater works fine and starts blowing hot air quickly after startup, so I don't think this is a thermostat issue. Rather, it looks to me that ECU is being told incorrectly that the enginge is cooler than it is (maybe due to a lazy temp sensor?).
Which sensor does VAG-COM get its reading from?
And, how do you explain the difference in reading (temp gauge vs. Block 001)?
P.S.: Continuing STFA and just read that there are two sensors: one feeds the temp gauge and AC equipment; another one feeds the ECU. So, my guess is that the one that feeds the ECU is bad and it is located on the back of the engine block
Correct?
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the temp sensor located @ the back of the block by the passenger
side firewall. Its a quick $6 fix w/new sensor and c-clip. Just make certain car is cool before changing since colant will be hot and still under pressure. You can release the pressure by unscrewing the resevoir cap first.
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$6 is a "revised" green sensor, its connector looks different from mine...earlier model perhaps?
<center><img src="http://www.ecstuning.com/stage/images/product/iadmin/943_x450.jpg"></center><p>
Pic from ECS ^^^^.
The one that matches my sensor (4-prong blue one), P/N 078 919 501B, is $16.
Now, they also have this two-prong blue one: http://www.ecstuning.com/stage/images/product/iadmin/1802_x450.jpg .
Any idea what it's for? My Bentley component location table does not mention any other temp sensors.
Pic from ECS ^^^^.
The one that matches my sensor (4-prong blue one), P/N 078 919 501B, is $16.
Now, they also have this two-prong blue one: http://www.ecstuning.com/stage/images/product/iadmin/1802_x450.jpg .
Any idea what it's for? My Bentley component location table does not mention any other temp sensors.
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99.5 1.8t Q Tip. My sensor was blue...
Here is the funny thing. No matter how simple the job, there is always a way to make it more...hm...exciting ;-) . Like, while removing the old sensor, ,not realizing that the old o-ring is still in the socket and then breaking the plastic clip when trying to secure a new sensor...lol!
I had to make a new clip from some scrap plastic I had laying around in my garage...
Anyway, a new (blue) sensor is in place of the old (blue) sensor now. Will see if my fuel economy improves.
P.S.: edited my sig to include car info
I had to make a new clip from some scrap plastic I had laying around in my garage...
Anyway, a new (blue) sensor is in place of the old (blue) sensor now. Will see if my fuel economy improves.
P.S.: edited my sig to include car info
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