How to get the plastic U clip back in place for the coolant temperature sensor ?

A

A2b2...

Member
This relates only to the 1.4 TDI engine, specifically the (engine code) ATL (90bhp). Following those who have gone before me I am attempting to change the above sensor. All has been easy compared to the last job of putting the U shaped clip that holds the sensor back in place. Now I know this is a job that lots of people here must have paid to have done or done it themselves. So I'm not breaking any new ground except...I think I must have read most of the posts relating to this subject. Yet I have not found any detail on how to go about putting the clip back in place. So if/when I manage to do it perhaps I can add to the knowledge base by sharing my knowledge. You would think it is a straight forward job, and maybe it shows my lack of skill. I have spent several hours over 2 or 3 days trying to put the clip back in place. I don't know how much is charged to have this sensor changed but apart from the clip it has not been difficult. At first its difficult to find the sensor. Even when you know where to look its difficult to even see the sensor at first.

What I would like to know is is there a knack to getting the 2 arms of the clip to locate into the 2 slots?

There is a rubber pipe approx 1.5cm in diameter (in the 6 o'clock position when looking down from above) immediately below the slots for the clip which prevents (or makes it very difficult) the clip to be manoeuvred so that the 2 arms are vertical in relation to the 2 slots which are centered around the 9 and 3 o'clock positions.

I can get the visible arm of the clip to locate into the slot very easily, but the non visible arm is always a few mm to the right of the slot. I can just feel the end of the un visible arm and move it slightly. Not enough to move it far enough left to drop it into the slot.

I do have a plan B, take it to the local garage, but when I am so close I am reluctant to. So If anyone knows how the clip fits in it will help me and possibly others in the future.

Jerry
 
You have to make sure valve is seated right then it just slides in.
Dont be shy push it home in there.
I was more bothered about dropping the clip

Sent from my SM-G935F using Tapatalk
 
Tie a long bit of cotton onto the clip, so that I you drop it, just pull and up it comes. The clip goes on easily if the sensor is pushed home enough. I didn't have any problems when I did mine.

Chris
 
Hi Jerry,

And welcome.

As has been said, the retaining clip will slide into place with reasonable ease once the sensor is pushed fully into place (although some force is needed to push the clip).
Ensure that the old O-ring seal has been removed, as the sensor will not fit correctly if there are two O-rings in place, and therefore it will be impossible to fit the retaining clip.

Something else to consider is the sensor and O-ring supplier.
It has been noticed on several occasions that non-OE sensors and O-rings can give various negative issues.
Genuine parts do cost more, but it's worth paying.
If you manage to get it all together and you have a leak, or the sensor isn't accurate, removing and replacing again also means spending more money on coolant too, as well as the time to redo the task.

Have you tried putting the old sensor back in place and securing it, just too see if that goes easier than you've experienced so far?

Also, as Chris suggests, tying a thread of cotton on to the clip is a useful tip if you push hard and the clip flies off, as you'll be very lucky to locate it in the engine bay (it's very chameleon-like).

Good luck and let us know the outcome.

Cheers
Jeff
 
Thanks for the really prompt replies. I was out early this morning making sure the sensor was pushed all the way in - using a long bladed screw driver to do so. It seems seated to me. I think if I push any harder I'm in danger of deforming the plastic (4 pin green coloured ) part of the sensor. I do not think there is more than 1 O ring, but I'll check again later today to confirm.

I have not tried putting the old sensor back, apart from not having the Audi rings on the brass part the new sensor looks identical in shape and size, but I am verging on desperation so will try it.

Btw, I've smeared silicon grease on the o ring which I think makes it quite easy to push the sensor into place.

I bought the sensor from a shop on Ebay. It is from Beru, a German manufacturer, who according to Wiki are "one of the 4 major manufactures of OE parts in Europe". It cost £17, I have seen prices up to £41, so I am not 100% sure its genuine OE.

I changed the ( admittedly easier ) fuel temp sensor with absolutely no problem. Btw, I have attached a thin piece of wire to the clip, I would have lost dozens otherwise.

I'm presuming the rubber pipe ( oil pipe ? ) which is so in the way was not removed when you guys changed your sensors?

Jerry
 
I bought the same one as you via Ebay too.
Just check old and new has O ring still on them and dont try to do it warm,as warm hands may make something else happen and I dont mean burn yourself
I didnt need a screw driver but did twist a little as I pushed it home.
Its just awkward leaning over from the front thats for sure.
I reused the Audi clip but you should concentrate on getting valve into place then the clip



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Still no luck. Thanks for the encouragement. I need to look at it with a fresh pair of eyes tomorrow.

Chubby brown, how has your been since you fitted the Beru sensor? It would be good to know that hot/warm starting is no longer a problem.

Jerry
 
Chubbybrown, since you ordered the same sensor as me, where did you buy your coolant from?
I'm not sure what is in mine but I want to buy genuine G12.

Jerry
 
Are you certain you have G12 in the car? It was being discontinued right about the time the A2 was being manufactured.
If you know what you have (either G12 or G12+), buy what you have as they cannot be mixed.
If you do not know what you have, buy G12++/G13 as they are more modern coolants and are fully backwards compatible (G13 is G12++ but more environmentally friendly).
When reading the description, make sure that it actually mentions corresponding to TL774D (G12), TL774F (G12+), TL774G(G12++), or TL774J (G13). I have seen coolants called "G13+ longlife", which, upon careful reading, turns out to be G12+.

Compatibility chart
 
Thanks for taking the time to type out all the numbers. As I've lost an unknown amount of coolant and as I am ( optimistically? ) planning to keep the car for another 10 years, then I think getting the system properly flushed out and refilled with G13 - is the way to go.

Still no success with the clip. I must have incorrectly located it 50 times. Each time everything looks and seems to click into place but the non visible arm is always to the right of the slot resting against the plastic part of the sensor. No matter how much I twist, put pressure on the left/right of the clip it never locates with both arms in the slots.

After typing this I'm thinking I must check again to see there's nothing inside the housing preventing both arms from dropping into the slots.

Jerry
 
Hi Jerry,

What is the outcome of putting the original sensor (with original O-Ring) back in place and fitting the clip.

I suspect that if you were to use a digital vernier gauge to measure the new O-Ring, or sensor, and compare it to the old, you'll find a difference.
I have noticed similar issues with non-OE sensors and O-Rings as well as the 2 halves of the sensor not reading accurate temperatures.
I have replaced a number of temp sensors on both TDi 75 and 90 and would only use genuine parts ( and I have no affinity or affiliation to Audi).

When you factor in the cost of the new coolant you'll loose if you need to take it back out again (1.5lts of G13 needed to top up after chaning the sensor) I can't see it makes any sense not to buy OE.

If the old sensor and old O-Ring allow the clip to fit, and you are determined to keep and use the Ebay item, you could try using the old O-Ring with the new sensor.

I presume you can remember how the retaining clip came out of the housing, how much effort was needed to start the clip moving and if you needed to bend the clip to withdraw it fully?

OE Part No's and price:

Sensor - 059 919 501 A - Approx. £40 inc VAT
O-Ring - N 903 1168 01 - Approx. £1.75 inc VAT.
Retaining Clip - 032 121 142 - Approx. £0.75p

The O-Ring spec is 19.6 x 3.65

Crew Audi offer discounts on this forum, so it might be worth asking on the below thread what their cost might be.
http://www.a2oc.net/forum/showthread.php?31825-Hi-from-Crewe-Audi!!&highlight=crew+Audi

Cheers
Jeff
 
A2b2... said:
Still no success with the clip. I must have incorrectly located it 50 times. Each time everything looks and seems to click into place but the non visible arm is always to the right of the slot resting against the plastic part of the sensor. No matter how much I twist, put pressure on the left/right of the clip it never locates with both arms in the slots.Jerry
Click to expand...

Jerry,

I admire your perseverance, I would have given up by this point!

The location of the sensor for the TDI is not ideal, have you tried using a mirror or a mobile to take a photo to show what's happening when you attempt to insert the clip? Here's a website showing the same fitting for a different car, if only the A2 was as accessible.....

http://www.motor-talk.de/bilder/tem...rgeber-wechseln-g15204037/g62-i203241167.html

Steve
 
Mustang-owner - I have to confess I haven't tried fitting the original sensor. I was figuring that my new sensor would have come off the same assembly line as an Audi stamped one. I will try with the original. It will be interesting to see if its any easier.

I no longer know which is the original clip ( or O ring )and I lost an O ring this afternoon when triple checking that there was not still an O ring stuck in the housing.

I actually broke the end off one of the clips today in one of my many attempts at fitting. It seemed that the new O ring I was forced to use ( the previous is somewhere in the engine bay or on top of the undertray ) was slightly bigger when fitting onto the brass side of the sensor. Could the one I dropped have been the original and have shrunk slightly over the past 13 years? It still seemed "within tolerance" in every aspect from an eyeball perspective.

Will definately be buying genuine OE G13.

I remember pulling the clip out downwards in the 6 o'clock direction. It was difficult at first because I could only just feel the end of the visible arm of the clip. I rotated it as much as it would move, bringing the arm slightly further into view. Then positioned a small flat bladed screw driver onto the end and pushed down. It fought to remain where it had been for the last dozen or so years and it definitely felt like victory once I'd won.

Jerry
 
Catnip64 - That's a great suggestion re using a mirror. Not seeing what's happening on the far side is the biggest difficulty. Something to try in the morning.

Agree re accessibility and if you do discover the clip you bought from "one of the 4 major manufactures in Europe" turns out not to be OE, or as good as then replacing with the sensor in the vertical would mean little to no coolant loss.

Jerrry
 
The clip has been fitted. I want to get this down whilst it's still fresh in my mind.

How I did it:

It took me maybe 10 hours to put back the plastic U clip securing the coolant temp sensor. If I knew then what I know now I'd say it would only take me anywhere from 10 mins to 30 mins. The only tools I used were my hands. I have to say I have thin fingers and average size hands.

The trick is to push your right hand (I'm left handed but it makes no difference) as far round the back of the housing as you can. It is possible to feel enough of the far side of the housing to be able to make sure the arm of the clip (going into the far side of the housing) can only move within a narrow range. i.e 1cm and certainly not off the end of the housing. Whilst doing this, push the clip up with your left hand and it should slide into place. You can tell if its located because its impossible to feel the far side clip arm. Whereas if the far side clip arm is not located in the slot you can feel with the tip of your finger the top of the clip arm and it can be flicked / moved slightly with your finger nail. To try to throw more light; by pushing your right hand as far as it will go round the far side its possible to keep hold of much more of the clip.

The other important thing to note is that I found it much easier to do with the electrical contact cap dissconnected from the sensor and tucked out of the way. There is a space away from the sensor more towards the front of the car where it sits happily until you are ready to connect it onto the end of the sensor. I'm pretty sure it would not be possible to get your right hand in far enough with the electrical contact cap still in place.

Another thing to note is the necessity IMO, to remove the air pipe and a plate which the electrical connector mentioned above is linked to ( it seemed to be glued to the plate in my case )

You need to have the same access as you see in the photo attached.

http://http://www.a2oc.net/forum/attachment.php?attachmentid=12620&d=1372893323

Thanks for all the help and interest. Knowing others had managed to put the clip back was invaluable. As is this club.

ps, I tried using a mirror as suggested above but it was way too big. It would have possibly meant I'd have got the clip in sooner, but it would have to be something like a Dentist's mirror as the space is so tight.

pps, I did not try to fit the click using the previous sensor (as suggested previously) as I thought that the slots were wide enough to allow any slight difference in size or thickness to prevent any problems. In the final analysis I feel it was a more enjoyable rewarding experience than a troublesome one.

Jerry
 
It was getting to the stage i would have come and done it if you were closer.
(My prob with my one was the Temp Gauge not sitting at 90 btw)
As for Cooloant euro car parts do the pink coolant for I think mine was about £20 for 5 litres,just wait till they have a 35% thing on which is almost like being annoyed about missing a DFS sale :)
 
I have been struggling to get this clip properly in place as well. First of all, you may want to ascertain that the plastic clip will fit. Insert it with the sensor out. My sensor came with a plastic clip that was too thick to fit in the slots and I used the old metal clip.
Also as suggested before, ensure there's no old O-ring in the tube/housing and the O-ring on the sensor is seated properly.
If you have the cable connected to the sensor, it may affect the position of the sensor. Disconnect it and make sure the sensor goes in dead straight.

Good luck!
 
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