Water Temp Sender Woes!!

[Cupra_UK]

I tried changing the Water Temp' sender this evening as I’ve been having the erratic temp gauge syndrome.

I currently have the old black type. Straight forward enough job to change. However when I received the new green type there was no 'O-ring'. I thought I would just use it from the old one. But when I took that off there's no O-ring on that either... Instead there was some green sticky stuff... some sort of sealant I assume?

OK, no O-ring so I decided to replace the black one and get an O-ring tomorrow. Except after replacing the original black one and driving for about 10mins (to the gym). As I parked up lots of steam and coolant started gushing out.

What I'd like to know is can I use any type of O ring that has the right diameter or does it have to be a specific one for the sender?

Not sure what to do now... I could probably go home and get some coolant but what's the difference between red (currently in the car) and blue anti freeze (which I have at home)...?

Some help here would be great please.

 

[Cupra_UK]

Limped home as it wasn't far. Temperature didn't rise over 90 so very lucky to be so close to home.

Had a fiddle with the Sender and it seems to be very loose despite the clip being in place. I can't pull it out because of the clip but it seems it's not held it down sufficiently either.

Can someone tell me, is the O-ring that comes with the sender quite thick? Does anyone have a part number please?

EDIT: Just found the part numbers... hoping VW/ Seat/ Audi keep the rings in stock?!

For Ref:

OLD -Temperature Sender (Black)
Part#: J78-919-501C

NEW/Updated - Temperature Sender (Green)
Part#: 059-919-501A

O-Ring
Part#: N90316802

Retaining Clip
Part#: 032-121-142

 

[Saul]

ecp / gsf will have the o-ring in stock, you do need it (as you found out)

 

[Feel]

And, to make things worse - the sender you replaced has nothing to do with the temperature gauge. Sorry.

 

[Cupra_UK]

And, to make things worse - the sender you replaced has nothing to do with the temperature gauge. Sorry.

Really??? Oh Cr@p!

From what I've read this is what should be causing the fluctuations on the temperature gauge. Which sensor is it then? Have I gone through this needlessly?

EDIT: This is one of the treads I'm referring to... http://www.seatcupra.net/forums/showthread.php?t=147146&highlight=irratic+temperature+gauge

Suggests it will be this sender... is this not correct?

 

[Bosher]

And, to make things worse - the sender you replaced has nothing to do with the temperature gauge. Sorry.

Feel...... I might be wrong mate but my understanding is that the Engine Coolant Temperature (ECT) Sensor 059-919-501A provides a signal to the ECU via 1 pair of wires and to the temp gauge via the second pair.

And according to all the VAG forums I've read is the most likely cause of the temperature gauge varying between the normal (center) position and almost the minimum position during normal driving.

I'm just about to swop mine out as i keep getting an intermittent fault showing on it according to VAG-COM, however my gauge behaves fine, so my problem is on the ECU side of the sensor. I've also tested the sensor according to the SEAT workshop manual and it gives an unusual reading, so it's got to be the right sensor.

 

[traumapat]

ecp / gsf will have the o-ring in stock, you do need it (as you found out)

or sidlows in horley? hopefully a proper fitting o ring should sort it unless the pipe is damaged.

wonder why sealant was used? bigger hole in pipe or lack of an o ring?

 

[traumapat]

And, to make things worse - the sender you replaced has nothing to do with the temperature gauge. Sorry.

so the black/green sender relates to engine performance only?

gauge controlled by thermostat?

or coolant bottle sensor?

must admit the first time i had gauge issues it was accompanied by poor cold idling. the sender had faulted on vagcom ... and replacing it stopped both issues.

i now get it hanging around 80 alot... but vag com comes up clean. and cars running fine.

 

[Cupra_UK]

Thanks Bosher, most of the posts I've read point to this too.

I have no warning lights and the coolant has always been at the normal level when the needle fluctuates like this. Considering the location of the sender it seemed logical to be this at fault.

or sidlows in horley? hopefully a proper fitting o ring should sort it unless the pipe is damaged.

wonder why sealant was used? bigger hole in pipe or lack of an o ring?

I've just called Seat in Hookwood. They have them in stock so will pick one up along with some G12. Could someone please confirm how much I'll need? I don't have my user manual to hand.

I sealant is green in colour and it’s like a hard putty type substance. I couldn’t see it anywhere but the part of the sender that wear the O-ring. Before unplugging it from the plug, I though it was the updated green type. Seems like a bodge job due to lack of O-ring. Or at least I hope!

The O-ring is quite thick so fingers crossed this will seal it.

 

[traumapat]

Thanks Bosher, most of the posts I've read point to this too.

I have no warning lights and the coolant has always been at the normal level when the needle fluctuates like this. Considering the location of the sender it seemed logical to be this at fault.



I've just called Seat in Hookwood. They have them in stock so will pick one up along with some G12. Could someone please confirm how much I'll need? I don't have my user manual to hand.

I sealant is green in colour and it’s like a hard putty type substance. I couldn’t see it anywhere but the part of the sender that wear the O-ring. Before unplugging it from the plug, I though it was the updated green type. Seems like a bodge job due to lack of O-ring. Or at least I hope!

The O-ring is quite thick so fingers crossed this will seal it.

ask john in parts about the coolant. i think they do a top up bottle. depends how much youve lost already. usually it`ll poor out but then stop but if its leaked under pressure

sure you know but cold engine only for this job.

let us know if it sorts the problem

 

[Saul]

if you get the red light and a beep on the temp display, its the sender, if the temp is shooting over 90, its the thermo in the res

 

[petay_pan]

I was just about to post about what I believe to be a similar problem I'm having (just fixed the dam key fob so I expected something else to go wrong!). Don't mean to hi-jack but I just want to see if this is the solution to my prob too.

During the winter months on the cold mornings when I turned the car on sometimes I would get 3 loud beeps from the dash and the temperature gauges red light would flash. I could deal with this prob but recently I have had problems with the gauge in the car where I will be driving along and the temp gauge will drop to resting place and then creep up a bit then back to rest then back to normal middle position all completely randomly. It doesn't go over the 12 o'clock mark though.

This problem had me worried because my thinking was that if thats the message the gauge is getting then surely the ecu is getting the same info and could be adjusting fan speed and other engine bits accordingly that might not be too healthy? Fear is in summer heat (if it ever shows its face) the temp gauge drops and the car things the water is cold it would try and maintain the coolant and could overheat.

I'm reluctant to get Seat involved because I need both arms and legs and not willing to exchange them for this to be fixed with them if I can do it myself?

Engine is standard, not sure what I need to do to fix this or how I can find whats broke. I've got access to VAG-COM just not sure how to use the thing!

Any help appreciated want to iron out all these problems once and for all since the recent fuel and tax stuff it looks like car will be with me a while longer.

 

[Cupra_UK]

ask john in parts about the coolant. i think they do a top up bottle. depends how much youve lost already. usually it`ll poor out but then stop but if its leaked under pressure

sure you know but cold engine only for this job.

let us know if it sorts the problem

I'll need to do a complete flush. The car was cool when I initially removed the old sender so a minimal amount was lost (not enough to go down from the Max line). But then I replaced the sender with the green one (without the ring) and turned the engine on. Whilst it was running I could see water dripping but left it on to check where it was coming out from. It's not immediately obvious. I changed it back to the black one and it was still leaking. Anyway, with all the faffing about I lost almost all of it. I've topped it up with water so will need to drain this.

Bottles apparently come in 1.5 litres and with 50/50 ratio would 3 litres cover it?

I will update the thread about whether the initial problem gets sorted or not. It'll probably take a few journeys to tell as the gauges behaviour was a little unpredictable.

 

[Cupra_UK]

Petay pan, it seems you have the same problem. This is not uncommon and assuming I have the correct part, it's very easy to change yourself. I've made life difficult for myself by not being thorough. I didn't expect the new sender to not come with an O-ring.

Watch this space.

 

[traumapat]

check with the dealer re the amount to fill from scratch.

 

[Bosher]

As I understand it the sensor has 2 separate channels 1 for the ECU and 1 for the gauge.. which explains why my gauge is behaving fine, but as VAG-COM says it's getting an intermittent signal from the sensor I'm assuming the ECU side of the sensor is shagged.

Which could explain why I'm getting a drop off in performance every so often for 5-20secs then the power comes back on.

As the sensor is pretty cheap and easy to swap out I'll change it first see if that does the trick.

 

[Muttley]

The sender unit contains two separate sensors, one feeding the ECU and a separate one for the dashboard gauge. So the one thing you can be certain of is that the dashboard gauge does *not* show what signal the ECU is receiving.

 

[traumapat]

that explains things
thanks chaps

 

[Cupra_UK]

Picked up the O-ring, a spare clip and two 1.5 litre bottles of G12+

According to the parts guy I will need 1 and ½ bottles at 50:50 mixture with water.

I'm going to flush out the G11 I put in last night with water before I add this. I assume I need to have the car running when I do this so the pressure pushes the water through? Is the bleed value on the passenger's side under the car accessible without removing the undertray?

Alternatively can I just slot a drainage pipe (garden hose) into the temperature sender location and flush it out but adding water to the expansion bottle?

 

[Feel]

The Coolant temp sensor (G61) is the one that is commonly replaced with the "green top" sensor, this one that relates the engine temperature to the ECU for the cold running/warmup cycle. When the black top sensor goes, the car runs rich...

The Temperature Gauge Sender (I think it's G62) is in the thermostat housing and feed the temperature gauge. This one causes the gauge to rise and fall 0-90'C or sit at 70'C.

The coolant level sender probes are bonded into the header tank - these ones scale up and cause a false reading, especially when it's cold (and I assume the coolant contracts, so the level drops a bit). These ones give the three beeps on startup and flashing red light. Clean the probes by scratching with a screw driver, or replace the coolant bottle.

Edit: The G61/G62 business might not be right....