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Discussion Starter #1
So, I noticed yesterday after my car had been warmed up and driven for about 15 mins and the temp was about 65 outside my temperature gauge was all the way on the left, as if it was before I warmed up the car. Drove around for a bit and it started to move a few notches then the needle again dropped down all the way to the left. Does that mean that the gauge is broken, or does that mean I have a problem that I should be concerned? tia
 

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I had the same issue with my car and just replaced the temp sensor (green) on Saturday. Now it work perfect. It's a 5 minute install ....

Alex
 

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Becca it is the sending unit for the coolant temperature. Since you have a V6 I can't help with where it is located but on the 18.t's it is a 15 minute job max. Also it is not in the dash. it is under the hood.

Pete
 

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Took my V6 to the dealer and the guage wouldn't act up but then they put the computer on it and it showed a reading of -46 degrees. Pretty funny. Anyway it was replaced on extended warranty.
 

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Discussion Starter #7
Bmpassat said:
Becca it is the sending unit for the coolant temperature. Since you have a V6 I can't help with where it is located but on the 18.t's it is a 15 minute job max. Also it is not in the dash. it is under the hood.

Pete
Well you all seem to think it is the same issue, and the fact that it is under the hood verses the dash makes me happy. I will reference my Haynes manual and see if I can find it there. So I would just replace the temp sensor? Just want to verify ;-)
 

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Yup just make sure you do it when the engine is cold and open the top on the coolant resevoir, to minimize the coolant loss. The other reason to do this when the engine is cold is that when coolant is hot and pressurized it will make a mess and present a potential burn hazard.

Pete
 

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i dont know about you guys

but this was a pain in the ass for the v6 took like 10 min to take off the clip replace the senosr and then like an hour to get the clip back on

it was in a tight place
 

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If you are planning to do this yourself, the sensors are cheap and available through Impex, ECS, Liberty and other sources. You need to determine which sensor is installed in your car; they are not interchangable. Here are the part numbers and prices that I found on Impex...

Blue Sensor - 078 919 501B - $18.27
Green Sensor - 059 919 501A - $4.85

You should also replace the clip and O-ring seal on the sensor (cheap), and you will need to replace the coolant that is lost when you remove the sensor.

It is a fairly easy job, though more difficult on a V6 than a 1.8T. On the V6 the sensor is located in a cross-over pipe, leading between the two cylinder heads, behind the engine, near the passenger side of the car. I've only changed one on a 1.8T, but the trick I read on the V6 is to leave the wiring harness connected to the the sensor. Remove the retaining clip, then use the wiring to pull the sensor out of the manifold and up from behind the engine. Swap the sensors, make sure you get the old seal out and put a new one on, then reverse the process to get the new sensor into the manifold. Reinstalling the clip may be the most difficult part.

Yes, it is possible that a faulty temp sensor could cause some CELs and fault codes. The codes would probably be mixture related since the computer would think the engine is operating at a something other than its actual temperature. My guess would be that the car would be running too rich.
 

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Discussion Starter #13
jaero thanks for the part #'s and the additional info........you rock!!!.


Question though about this sensor. I have a bunch of codes I have been trying to trouble shoot. One of the codes is: P1141 which Thanks to Terry over at the Bentley forums this is what his answer was on one code that I was unfamiliar with:
"P1141 indicates a problem with one of the components involved in calculating the engine load, ie. the throttle valve control module, Mass Air Flow sensor, or throttle position sensor. Since you have 2 codes that could indicate a faulty MAF that's the area I'd concentrate on (it could also very well be causing your emissions codes). Start by checking the wiring to the MAF, make sure nothing is broken. The MAF's performance can be checked by using a VW scan tool."

Since I tore my airbox apart to trouble shoot these other codes:
P1129 ( Long term fuel trim too rich (bank2))
P1127 (Long term fuel trim too rich (bank1))
P0103 (Mass air flow sensor circuit, high input)
Could this all be related????? tia
 

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Coolant temp is used for fuel trims as well. If the sender is bad and the car thinks it's cold all the time, you might be driving around with the warm-up fuel enrichment settings. That would make the car run very rich and could cause what you are seeing with those other codes. How's your fuel economy been? You should probably fix the sender, clear the codes, reset the ECU to clear out your fuel trims, and see if they come back.
 

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Discussion Starter #16
Macabre said:
Coolant temp is used for fuel trims as well. If the sender is bad and the car thinks it's cold all the time, you might be driving around with the warm-up fuel enrichment settings. That would make the car run very rich and could cause what you are seeing with those other codes. How's your fuel economy been? You should probably fix the sender, clear the codes, reset the ECU to clear out your fuel trims, and see if they come back.
Thank you MAC!!! :bow: That makes sense! My fuel consumption has been horrific, but I just kinda decided that it was from the wheel size increase. I think with all the info I have gathered that will be my project to work on. Again, I really appreciate your insight ( I knew you had a great answer, you always do!!!! :))
 

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i paid 12 bucks total for sensor and washer ( green ) at the dealer same price as at esc tunning but i didnt have to pay shipping
 
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