Engine Temperature Warning every morning

[WildBruce]

Hello Guys,

On cold morning I get warning, that looks like an engine temperature warning, and after a couple of minutes, it goes away.
Bring up the coolant temperature through the climate control panel [thanks for the new trick Leshkin] show it at 30 degrees C, so I inclined to think that there are no engine temperature issues.

What I wanted to know is if anyone else has had this, or if anyone had any ideas on whether it was serious?

Took a photo, and uploaded it now [and have a flickr account to show for it]
http://www.flickr.com/photos/31818153@N04/2978049145/


Any ideas?????

 

[WildBruce]

So, after a bit of digging [Google is my friend] looks like something in the coolant system, page 4 of the new S3 quick reference guide "coolant system error" so I guess it is the same for the older model:
http://www.audi.co.uk/etc/medialib/...ts/owners_area/Choose_Model.Par.0004.File.pdf

As my coolant levels are good, as well as my windscreen washer fluid levels, I am inclined to think that which ever sensor is reporting those levels back is a bit screwy, as I put four litres of water in to the washer fluid a couple days ago, and it is telling me it is to low again .......

Anyone know if it the same sensor?

 

[benr]

sounds like screwy sensors due to the cold or something.. But im no expert, Im sure someone will tell you what the problem is likely to be.

But it wont be the same sensor for both warnings

 

[leshkin]

You forgot to mention that there are no DTCs being logged for this, as we scanned the car last week. My guess is that you have a screwy sensor also, which bombs out when it's cold.

Anyone know which sensor the temp info is being sent from? Might be worth checking if that works correctly. Going to check the manual for wiring details, but I'm afraid that won't be enough as the signal is probably going through the ECU... Will let you know if I find it

 

[leshkin]

I think I found it Possibly the "coolant temperature sender" is the sensor that is responsible for the temperature info that is sent to the DIS ... I remember having an issue with mine being a lying little s**t and got it replaced by VagCheck guys with the new, green one, as opposed to the dodgy original black item.

I will have to read up on how to actually test it. It's about 20 squid to replace, but don't quote me on that. Anyone know of a process to test this ****** before replacing it?

 

[HTC]

That warning doubles as the coolant level. Seen a fair few bad sensors in the coolant expansion tank cause this in cold weather even when topped up to the correct level.

 

[Essflee]

My A3 1.8T used to do this every morning in the winter and was fine in the summer. The local specialist's round my way found the problem, like said before, it was the sensor inside the expansion tank that measures the coolant level that was at fault, he simply cleaned it up with a bit of wet n dry as it was coroded, however after a year it did return with the problem so i just chose to ignore it even if it was annoying, at least the car was alright.....

 

[1animal1]

yup this happend in my old A3, replaced the coolant sender and turned out to be the expansion tank which has integrated sensor.....this ones started doing it very sporadically

 

[WildBruce]

Levels are defiantly correct, unless they reduce rapidly overnight, and warm up damn quickly in the morning, which I severely doubt.

Looks like the sensor is likely the best thing to look at, so just need to figure out if there is a way in which it can be tested?
I guess it is only a couple of quid to replace it, so maybe just do that and see what gives [Need to do my hazard light switch as well anyway.]

 

[Essflee]

Off memory....i think you unscrew the sensor from the top of the expansion tank and pull it out, it looks like the fillerment in a kettle, maybe giving that a clean first may help, if not then buy a new one.....

 

[1animal1]

yes but its the level sensor that isnt sensing....telling the ecu that it iasnt the right level

 

[WildBruce]

Is there a separate warning for a temp issue vs the one I posted, which looks to be about the levels? Cause if both issues [low engine temp & low coolant level] throw up the same image on LCD display then it could be either one right?

 

[Essflee]

Is there a separate warning for a temp issue vs the one I posted, which looks to be about the levels? Cause if both issues [low engine temp & low coolant level] throw up the same image on LCD display then it could be either one right?

That fault symbol your've posted up is exactly the same as the one i used to get, it does have multiple symptoms, but from how your've described your problem it is identical to what i was experiencing. All i know is the mechanic cleaned up the prong as described and bob's your uncle.....sorted !!

It only ever did this in the morning from cold, if i drove to a destination and left the car to cool down it wouldn't do it....purely a cold morning thing. It may be the coolant level showing the false reading or the coolant temp, either way, the problem was rectified......

 

[Wak-VAGCHECK]

Assuming the S3 expansion bottle is the same or similar to a TT ( and an old mk2 Golf, and old problem vee-dub owners wil know)

the sensor consists of two metal prongs the dip into the water and get a coating over time causing this error.

cold is low and when warm the coolant expands to touch exposed parts of the prongs.

Look in your expansion tanks, if you can see 2 metal prongs, try to get a screwdriver or some tool to be able to scrape the prongs and clean up the metal specially the lower dipped portions and then see how you get on.

Others have topped up coolant alightly and cured it but you are just lifting the water level to better parts of the metal and not fixing the issue.

Its worth a try!

 

[WildBruce]

I wanted to update this sooner, but for some reason the forum database always brought this site down for hours on end [doesnt soem one look after this?] ......

ANYWAY ..... I used a long thin flat head screw driver to scrape off the white residue on the two pins, and it did the trick. I was a little hesitant at first, but once I saw how much reside there was on the prongs, I shaved it with a little more elbow grease, and this seems to have done the trick.

:thumbsup:

 

[1animal1]

ive just fitted a new bottle which looks loads better....only cost £10 from Audi too!! and solved the problem, 10 mins to fit and if your careful you wont need any extra G10

although i bought the G10 too and ended up with a nearly full yet open bottle.....well it'll just sit on shelf for 10 years grrr

 

[Essflee]

I wanted to update this sooner, but for some reason the forum database always brought this site down for hours on end [doesnt soem one look after this?] ......

ANYWAY ..... I used a long thin flat head screw driver to scrape off the white residue on the two pins, and it did the trick. I was a little hesitant at first, but once I saw how much reside there was on the prongs, I shaved it with a little more elbow grease, and this seems to have done the trick.

:thumbsup:

Glad you got the car sorted mate, but a word of warning, dont be supprised if the problem returns next winter....mine did, but at least you know the cause of the problem and your car is (really) fine and dandy......

 

[Dennis Moeller]

I've had that warning sign come on every morning (yes only on cold mornings) and I thought that it was more serious...got a little paranoid actually ;-)

But you guys made my day!

Thanks!!

 

[WildBruce]

I would say scrape off the build up on those prongs, as I would always want to be certain that that is the cause, and it will only take a few minutes, assuming you have something that can get in there and do the job.

Mine is still fine, so will leave it till it pops up again, which I am sure it will do in a year or two

 

[dantheman1986]

i get this same warning, is there no way to remove the sensor to clean it properly rather then scraping all the stuff off an lettin it fall into the header tank?

 

[WildBruce]

If you are going to go through all of that effort, you may as well change the expansion tank, as the only difference would be the price of the part, but in theory, you could remove it, scrape it clean, flush it out and replace it, but no idea on how to go about doing that ...... which is kind of why I took the easy way out.

If you do, please update here, as would be keen to have a crack .... in the summer of course

 

[Rachael]

The same thing happened to me. I had the timing belt, tensioner, water pump and alternator belt replaced on Monday and the warning light hasn't came on at all since then.

 

[Dennis Moeller]

If you are going to go through all of that effort, you may as well change the expansion tank, as the only difference would be the price of the part, but in theory, you could remove it, scrape it clean, flush it out and replace it, but no idea on how to go about doing that ...... which is kind of why I took the easy way out.

I did this two or three day ago. Dismantled the reservoir, scraped the prongs carefully off with a pair of long thin scissors and flushed it (even though there wasn't that much residue) and assembled it again. Problem solved. 15 min job.