Author Topic: Blue Temp Sender  (Read 4196 times)

Offline Dan-G40

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Blue Temp Sender
« on: April 02, 2012, 09:19:31 pm »
Seem to be having a little niggling problem with idling on the G, it's the general g40 not behaving itself symptoms:

Idle will sometimes 'stick' at 2k revs
If cold will sometimes run a little bit lumpy and hunt at just under 1k

It's a strange problem because it seems to be intermittent, sometimes I'll crack her up and everything will be fine... Believe it or not it seems to be fine when the weather is nice  ???

Anyway, I decided to check the blue temp sender. I unplugged the sensor and it doesn't alter the revs (enter 'service mode')... However, the previous day I managed to blow the boost pipe off the charger outlet (fixed when I tested), would the ECU store a fault for this and enter a 'safe mode'?

Am I to assume the Blue Temp Sender needs replacing? I read on here that the car not entering service mode is a general indication that the ECU isn't happy?

Where do you think the best place to start is?



Offline Chris_J

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Re: Blue Temp Sender
« Reply #1 on: April 02, 2012, 09:29:06 pm »
Not entering service mode could be caused by any of the engine management sensors, not just the blue temp sender. Are you sure that the engine is up to temperature when you're removing the plug?

As for the sticky idle that tends to hunt a little, I had this problem. Solved by adjusting the idle screw, as it was set too high. Try winding it in until it idles at around 950 rpm.

Offline Dan-G40

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Re: Blue Temp Sender
« Reply #2 on: April 03, 2012, 11:26:52 am »
I tried unplugging the sensor when I started it up and when I'd come back from a run out (temp was 90) - made no difference.

Where's the best place to begin troubleshooting with regards to the management sensors? I think I've done this before on my old G40 with a guide I got from Steve at Pitstop.

Offline hayesey

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Re: Blue Temp Sender
« Reply #3 on: April 03, 2012, 11:46:51 am »
look at the diagnostics threads in the FAQ sections and also the vagcom/vwtool thread(s) also in FAQ sections.

Offline Dan-G40

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Re: Blue Temp Sender
« Reply #4 on: April 05, 2012, 06:16:29 pm »
Not entering service mode could be caused by any of the engine management sensors, not just the blue temp sender. Are you sure that the engine is up to temperature when you're removing the plug?

As for the sticky idle that tends to hunt a little, I had this problem. Solved by adjusting the idle screw, as it was set too high. Try winding it in until it idles at around 950 rpm.

Tried it again and it works today, perhaps it wasn't up to temp...

With regards to the idle, it does idle at 950 when it isn't sticking, it only sticks every so often. I noticed though that it hunts slightly while the blue temp sender is disconnected. What would cause this? Timing being out?



Offline woody02

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Re: Blue Temp Sender
« Reply #5 on: April 09, 2012, 07:04:26 pm »

Tried it again and it works today, perhaps it wasn't up to temp...

With regards to the idle, it does idle at 950 when it isn't sticking, it only sticks every so often. I noticed though that it hunts slightly while the blue temp sender is disconnected. What would cause this? Timing being out?


Mines doing a similar thing mate, tried all sorts. Doing my nut in!