# Just changed the coolant temp sensor



## SimonBUK

Bit of back ground - have had the EML come on occasionally suggesting coolant temp sensor is faulty. Went to change once so cleared the code but started to piss it down so left it, fine for another few months.
EML came back on again.
Now fairly recently I've noticed the dash dial was only about 70 ° ALL the time (where I've seen it vertical at 90° before). Checked with my dongle and App and it said 67° so that was consistant. Looked like my thermostat must be stuck open I thought ?
Anyhow, just got around to fitting the new coolant sensor (yes it's an eBay special), the dial on the dash no longer reads anything, the dongle reads changes up and down but when it was showing 96 the code 49 check said it was 48° ?!
I turned the heater on and watched both the dongle reading and code 49 reading drop simultaneously down to the 80's and 30's - what an earth is happening ? Are the readings coming from different places ?
Why has the dash stopped taking a reading ?!
Any ideas ?


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## David C

The temperature sensor is two sensors in one unit.
One goes to the engine ECU, which you can see via OBD.
The other goes to the dash. 49c comes from the dash.


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## Hoggy

Hi, Code 49 can give incorrect temp reading if dashpod is faulty.
If you do replace ensure* genuine oem* is used, not oem quality from Ebay etc, unless you want to replace it twice.
part No. 078919501B early square type. part No. 059919501A later oval type
Assuming sensor is OEM & 100% the only reliable coolant temp indication is from ECU via OBD.
Dash should show 90 when actual coolant temp is anywhere between 82 & 98 ish
Hoggy.


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## SimonBUK

@davidc - Ah ok - but why would I get two different readings from the same point ?


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## David C

SimonBUK said:


> @davidc - Ah ok - but why would I get two different readings from the same point ?


Garbage sensor or faulty dash.


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## Hoggy

SimonBUK said:


> Ah ok - but why would I get two different readings from the same point ?


Hi, Either because of the Ebay sensor or dashpod is beginning to fail.
Many members have chased coolant temp probs because they fitted oem quality from Ebay etc.
Hoggy.


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## SimonBUK

Ok, so first thing really then is to get a genuine part and see where I go from there ?


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## David C

Step one is to put your old sensor back in.


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## SimonBUK

But when my old sensor was in it was constantly showing 67° on my dongle and I would occasionally get an EML light ?

At least now it's showing the temperature rising into the 90's and cooling down again when driving/turning the heater on (on my dongle).

I will hunt down a genuine Audi sensor when I can though.


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## Hoggy

SimonBUK said:


> But when my old sensor was in it was constantly showing 67° on my dongle and I would occasionally get an EML light ?
> 
> At least now it's showing the temperature rising into the 90's and cooling down again when driving/turning the heater on (on my dongle).
> 
> I will hunt down a genuine Audi sensor when I can though.


Hi, Perhaps there is nothing wrong with old sensor & stat is stuck open.
With old sensor back in & engine warm hold revs at 2k stationary, A/C OFF, does coolant temp rise > than your 70? if so stat is stuck open,
Hoggy.


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## David C

SimonBUK said:


> But when my old sensor was in it was constantly showing 67° on my dongle and I would occasionally get an EML light ?


EML for "Error in mapped cooling circuit" is 99.9999999% of the time the thermostat stuck open.


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## SimonBUK

With the old sensor in , it didn't get over 70 according to the dash & dongle, would occasionally throw the EML light suggesting coolant sensor.

With new sensor in , the dongle temp goes up into the 90's and back down again, dash temp shows nothing, code 49 check shows between 35-48 degrees (approx half of what dongle says).


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## silverbug

Whether it’s the thermostat or not , non-Genuine coolant temp sensors are generally trash, hence the suggestion on here always to fit Genuine from a known source.
I fitted a supposedly-Genuine sensor from a Lithuanian/Polish eBay seller and it made no difference to my dash gauge temps (would read 70 with a random rapid reading of 90 every now and then) so took it out, I now think it was a Chinese fake as it looked Genuine.
As it was lockdown all I could obtain was a Beru German-made but non-Genuine sensor and which seemed to work perfectly.
As the Genuine ones were about £50 the last time I looked I’ll run the current Beru sensor until it ever plays up, but it’s been in there 2 years without issue so far.


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## 237tonybates

Hoggy said:


> Hi, Code 49 can give incorrect temp reading if dashpod is faulty.
> If you do replace ensure* genuine oem* is used, not oem quality from Ebay etc, unless you want to replace it twice.
> part No. 078919501B early square type. part No. 059919501A later oval type
> Assuming sensor is OEM & 100% the only reliable coolant temp indication is from ECU via OBD.
> Dash should show 90 when actual coolant temp is anywhere between 82 & 98 ish
> Hoggy.


What year did these change hoggy , and are they interchangeable 

Sent from my SM-G973F using Tapatalk


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## Hoggy

237tonybates said:


> What year did these change hoggy , and are they interchangeable
> 
> Sent from my SM-G973F using Tapatalk


Hi, for vehicles from 1999 to 2000 only _(upto Chassis No. 8N-Y-015000)- square plug_ 
Square & Oval not interchangable.
Hoggy.


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## SimonBUK

Is there a place online to order a genuine one ?


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## Hoggy

SimonBUK said:


> Is there a place online to order a genuine one ?











RPS - for Volkswagen Group Genuine Parts


RPS - for Volkswagen Group Genuine Parts. 8,624 likes · 2 talking about this. Probably the best place to buy your genuine Volkswagen, Audi, SEAT and SKODA parts! Part of Listers Group Limited, a...




www.facebook.com




Hoggy.


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## SimonBUK

There is a VW garage where I am currently located - so popped in with the part number.

They want £60.66 ?! WTF ? Seriously 😳😂


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## davebowk

I took a chance and fitted a Febi unit and it's been fine so far, about 3 month Coolant Temperature Sensor fits AUDI TT 8N3 8N9 1.8 3.2 98 to 06 Sender Febi New | eBay


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## Hoggy

SimonBUK said:


> There is a VW garage where I am currently located - so popped in with the part number.
> 
> They want £60.66 ?! WTF ? Seriously 😳😂


Hi, This Febi sensor has been used in the past with success.


Febi 32510 Coolant Temperature Sensor - OE Ref: 059919501A | AVS Car Parts


Hoggy.


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## SimonBUK

Thanks for this - just ordered one so get it at the weekend.
It does look identical to the one I've already got but worth a go at that price.

I am going to get my dash repaired as found somebody that does it quickly and at a reasonable cost - be nice to know what the hell the messages and symbols finally say 🤣🤣


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## Hoggy

SimonBUK said:


> I am going to get my dash repaired as found somebody that does it quickly and at a reasonable cost - be nice to know what the hell the messages and symbols finally say 🤣🤣


Hi, A link to that somebody, maybe a help to others.
Hoggy.


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## PlasticMac

SimonBUK said:


> Thanks for this - just ordered one so get it at the weekend.
> It does look identical to the one I've already got but worth a go at that price.
> 
> I am going to get my dash repaired as found somebody that does it quickly and at a reasonable cost - be nice to know what the hell the messages and symbols finally say 🤣🤣


Make sure they have Mk1 TT dash pod experience, and get a couple of positive customer reviews. If they are cheaper than everyone else, there's probably a reason for that. 
Mac.


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## SimonBUK

Indeed, wasn't going to post a link until it was returned and installed in the car, but in case anybody else has used him and want to give feedback -



Cluster Repairs



One of the YouTube guys used him recently and was pleased.
Think the price was £80 - whatever p&p you use is on top of that. Quick turn around too if you want it.


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## Hoggy

SimonBUK said:


> Indeed, wasn't going to post a link until it was returned and installed in the car, but in case anybody else has used him and want to give feedback -
> 
> 
> 
> Cluster Repairs
> 
> 
> 
> One of the YouTube guys used him recently and was pleased.
> Think the price was £80 - whatever p&p you use is on top of that. Quick turn around too if you want it.


Hi, Thanks, added them to my list 
Hoggy.


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## SimonBUK

SimonBUK said:


> There is a VW garage where I am currently located - so popped in with the part number.
> 
> They want £60.66 ?! WTF ? Seriously 😳😂


Well RPS got back and they want £58 so that must be the going rate for them I guess.


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## Hoggy

SimonBUK said:


> Well RPS got back and they want £58 so that must be the going rate for them I guess.


Hi, Yes genuine OEM are not cheap, but they should work first time.
Did you order the Febi from AVS?
Hoggy.


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## SimonBUK

Yep, it's sitting in an Amazon locker waiting for me ! Should have it fitted tomorrow afternoon...


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## Hoggy

SimonBUK said:


> Yep, it's sitting in an Amazon locker waiting for me ! Should have it fitted tomorrow afternoon...


Hi, Keep me informed how it performs once in use. I have recommended it a few times without any probs.,
Hoggy.


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## SimonBUK

Well - so far so good !! Seems to be doing what it should AND gives a read out to the dashboard.

After getting the engine warm I sat with my foot on the throttle for a while, watched the temp rise.
It got to 95 then back to 92, rose again to 96 then down to 91 before rising again. So the thermostat must be working.
Turned the heater on full and the temp dropped even more.

The dash display seems ok and consistant with what the ECU is saying.

I think I may have had a sticking stat in the past unless the original sensor was playing up periodically, so might just change the stat in the future as it could be original.

So it appears the Febi could be a good budget alternative (for a while ?!), the one I bought from PureVue from eBay was not ! (It did give the temperature to the ECU but not the dash). 

I searched on Amazon for the Febi one and got it for 6/7 quid delivered.

Next job is to get my dash pod sent off for repair so I'll report back on that when I get it back.

Thanks for everybody's help 👍😀


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## Hoggy

Hi, If the stat is working correctly the coolant temp shouldn't have dropped below 85ish ECU... 90 on dash even with heater on, especially stationary.
Have you been able to check it while moving, as that will prove if the stat is working correctly.
Hoggy.


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## rlszer

SimonBUK said:


> Indeed, wasn't going to post a link until it was returned and installed in the car, but in case anybody else has used him and want to give feedback -
> 
> 
> 
> Cluster Repairs
> 
> 
> 
> One of the YouTube guys used him recently and was pleased.
> Think the price was £80 - whatever p&p you use is on top of that. Quick turn around too if you want it.


I've seen a few of Paul's repairs. When he started doing the TT one's, he was the only person who's repair looked original, in colour. I have no idea whether that is the case todayt.


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## SimonBUK

Haven't tested it extensively on the move yet no. Only had the chance to drive to the shops and back. The temp did drop below 85 with the heater on so maybe the stat is knackered then.


rlszer said:


> I've seen a few of Paul's repairs. When he started doing the TT one's, he was the only person who's repair looked original, in colour. I have no idea whether that is the case todayt.


Ok cheers - he said that the £80 repair uses a screen which is quite bright and the £95 repair uses a screen which is near to the original as he has seen


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