G2/G62 coolant sensor question

[Nobby]

Wassup chaps!

Had a lovely drive at the weekend to windy Colchester and back, and it was only when I got home that I noticed my high speed 600w fan going like billy-o. Checked gauges and all seemed fine - Coolant at 90 and the oil just below 90. When I turned the engine off the fans kept running and were doing so for about 4 minutes.

So, had a little tinker around and no visible leaks or loss of coolant. I went out about 20 minutes later and checked the temperatures on the dash compared to the A/C display and they didn't match initially. When the car was started the dash one went to 90 fairly soon but the A/C one was around 60 and steadily rose to 90. This time the big fan didn't come on though. When the A/C button was switched on the fan turned on again (and also off when turned off).

I haven't scanned it yet but will do tonight. Does it sound like the G2/G62 sensor is doing what it should i.e. aren't the dash/AC display supposed to be exactly the same? - the sensor does supply both of them doesn't it?

[Shoppinit]

They're supposed to be close. The G2/G62 is 2 sensors in one. One's a 2 pole thermo, the other is a 4 pole. I can't remember which one goes where. Check with the Vagcom what's going to the ECU, dash insert and hvac. If you've got an incoherence then that could set your fans off.

[Nobby]

Thanks Shop. They did eventually get to the same reading, I just wish I'd checked when the fans were on but needed to get my daughter out of the cold and into bed.

I'll check it all tonight when its cold too. I might just order a new sensor anyway.

[Shoppinit]

It does sound like a sensor issue. Wouldn't hurt to have a spare one anyway. Avoid ebay specials.

[Nobby]

My local Audi have them in stock.

Just for info: the A/C temp display for value 34 - on my car you needed to press the passenger side +/- (not drivers side)
Also the guide to change the sensor doesn't seem to work but that might be a flickr problem.

[Shoppinit]

Fixed the A/C procedure in the FAQ.

The flickr thing works fine for me:

http://www.flickr.com/photos/surgenor/s ... 29/detail/

[mavada]

[Nobby]

Thanks Mav

Is there anything you haven't PDF'd?

[Nobby]

And to anyone that cares - the parts numbers for the G2/G62 coolant sensor are:

059919501A - Sensor
032121142 - Spring clip
N 90316802 - Seal

[Ian_C]

I've just bought a four pin G62 coolant sensor from Stoke Audi at 35 quid. Its down the back of the block on my S4, almost central on a coolant rail that links the two banks, can access from above with one hand, not quite properly with two hands. Had a go at fitting it Saturday but couldn't get the circlip off. I'm worried if I cut the old one off I won't be able to get a new clip on. So more thought required!

[Shoppinit]

I've done it on a B6 S4 and I left a lot of skin behind. Not much room down the back.

I made a tool to get the clip off. Don't cut it it comes out quite easily. I'll see if I can find a photo.

[Nobby]

I've located mine tonight and added a little WD40 to the clip.

Also this:

16500 - Engine Coolant Temp. Sensor (G62)
P0116 - 008 - Implausible Signal - Intermittent

Case closed hopefully. Interestingly all 3 temperature displays (dash/AC display and ECU G62 via VCDS) all display slightly different readings. Signal is obviously intermittent as the fan didn't come on

[Shoppinit]

Here you go. The improvised tool to hook the clip off and the offending clip which I dropped down the back into the undertray.

[Shoppinit]

I've located mine tonight and added a little WD40 to the clip.

Also this:

16500 - Engine Coolant Temp. Sensor (G62)
P0116 - 008 - Implausible Signal - Intermittent

Case closed hopefully. Interestingly all 3 temperature displays (dash/AC display and ECU G62 via VCDS) all display slightly different readings. Signal is obviously intermittent as the fan didn't come on

Lovely. Nice to get confirmation.

It's easier on the RS6 than the S4.

[Nobby]

Love the tool Ben, don't you have any mole grips? Lol