S4 mysterious slow coolant loss found :)

[xpoweruk]

I have found 2 minuscule coolant leaks on the S4 rad return/overflow T pieces.
No visible signs off coolant loss,but upon closer inspection I found pink residue/coolant on both of them.
I suspect the T joints have gone a little brittle over time
The area i am talking about is highlighted in red in the below pic.

The fix is either replace the piping & clips or... http://www.halfords.com/motoring/paints-body-repair/adhesives/fixx-it-silicone-tape


I have used the fixx-it silicone tape before on a previous car.i used it on one of the main coolant hoses as I slipped with a screwdriver & punctured the hose.
The temporary fix lasted over 7 years without ever leaking & was still working when I was crashed into & written off.

 

[Bristle Hound]

I have found 2 minuscule coolant leaks on the S4 rad return/overflow T pieces.
No visible signs off coolant loss,but upon closer inspection I found pink residue/coolant on both of them.
I suspect the T joints have gone a little brittle over time
The area i am talking about is highlighted in red in the below pic.
View attachment 102530

The fix is either replace the piping & clips or... http://www.halfords.com/motoring/paints-body-repair/adhesives/fixx-it-silicone-tape


I have used the fixx-it silicone tape before on a previous car.i used it on one of the main coolant hoses as I slipped with a screwdriver & punctured the hose.
The temporary fix lasted over 7 years without ever leaking & was still working when I was crashed into & written off.

@xpoweruk - Going to have a good luck at mine tomorrow mate. Cheers

I'm wondering whether any brittleness is caused by the amount of heat the supercharged engine produces

 

[xpoweruk]

It's quite possible BH. I've found that type of connector to be a weak point on many cars,so the extra heat can only worsen things

 

[rum4mo]

Oh, I better look at mine as well, I'm sure that the designers of these push on fittings never intended them to get used in pressurised systems, what was Audi thinking about? The same goes for the pipe connection type on the quick release connector to the header tank - up there marginal at best.

Edit:- basic design matra on using these types of connectors on pressurised systems is - when under pressure, the coupler must "seal better" - these, now that I've seen them, will leak then blow off under pressure.

 

[scotty76]

Thanks @xpoweruk will check mine.

 

[Meemo]

nice spot! no longer have to worry its something more sinister

 

[scotty76]

Checked and all OK.

 

[rum4mo]

Yup, no signs of leakage - yet!

 

[jdp1962]

Will check mine tomorrow.

 

[xpoweruk]

Must just be mine then lol

 

[scotty76]

Must just be mine then lol

Good of you to take one for the team.

 

[jdp1962]

Checked mine this morning before starting up. It's only just above minimum with no sign of leakage. Time to call Bexley Audi.

 

[jdp1962]

Booked in for a coolant check a fortnight tomorrow. I've gone for a "while you wait" appointment, that way there's no risk of them washing the car without permission.

 

[ANDYTQ]

Mine seems to have a tiny leak on the header tank connection,I thought they had spilt antifreeze when they did the water pump,but level is slightly down.I shall order a new pipe I think and fit it myself ,I've spent enough lately on this thing and I'm not paying for labour as well.How much is the hose.?

 

[Bristle Hound]

Late to the party again lol

I've checked mine both hot and cold & all appears well, thankfully!

 

[meph137]

Booked in for a coolant check a fortnight tomorrow. I've gone for a "while you wait" appointment, that way there's no risk of them washing the car without permission.

Sorry for the thread resurrection I've got the same thing, and whilst I imagine there are a fair number of coolant leak causes, I'm interested what yours was? Or did they just top it up and have done with it?

Also, does anyone know if 2013 onwards cars use G12++ or G13?

 

[jdp1962]

Sorry for the thread resurrection I've got the same thing, and whilst I imagine there are a fair number of coolant leak causes, I'm interested what yours was? Or did they just top it up and have done with it?

Also, does anyone know if 2013 onwards cars use G12++ or G13?

They topped it up, and gave me a complementary bottle of G13, which I've used since to do the odd top up. There's no sign of any leaks anywhere, other than that the level mysteriously drops a little bit over time.

 

[meph137]

They topped it up, and gave me a complementary bottle of G13, which I've used since to do the odd top up. There's no sign of any leaks anywhere, other than that the level mysteriously drops a little bit over time.

Yes I can imagine that being the result. How much of a drop in level are we talking? Does anyone know if a slowly dropping level is normal for these cars?

 

[rum4mo]

The coolant tank typically says which version was used at initial fill, though I’d guess they would run out the older tanks before starting to use the later ones - anyway, for the car’s cooling system and for us, G12+, G12++ and G13 are all the same plus Vw Group dealers will not be holding stock of any G12+ or G12++ now, just G13 so maybe grab a bottle of that as it sounds like it might come in handy!

Currently we have a Feb 2011 S4 and an Aug 2015 Polo 1.2TSI 110PS SEL and neither of them have needed any coolant adding to their systems.

 

[meph137]

The coolant tank typically says which version was used at initial fill, though I’d guess they would run out the older tanks before starting to use the later ones - anyway, for the car’s cooling system and for us, G12+, G12++ and G13 are all the same plus Vw Group dealers will not be holding stock of any G12+ or G12++ now, just G13 so maybe grab a bottle of that as it sounds like it might come in handy!

Currently we have a Feb 2011 S4 and an Aug 2015 Polo 1.2TSI 110PS SEL and neither of them have needed any coolant adding to their systems.

Cheers yeh it does say G12 but I’ve gone for G13 anyway. I think I do have a leak actually as I have white chalky powder on the plastic engine covers :S


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[arad85]

I had this and found that the water pump was leaking. Symptoms were a coolant leak that would take 1-3 months (1k miles/month) to drop from max to min. On an V6 S5, the pump is front-centre and was spattering pink droplets just down from the top of the engine... Needed a new water pump...

 

[meph137]

I had this and found that the water pump was leaking. Symptoms were a coolant leak that would take 1-3 months (1k miles/month) to drop from max to min. On an V6 S5, the pump is front-centre and was spattering pink droplets just down from the top of the engine... Needed a new water pump...

How did you diagnose it, just from the spray pattern? Or did you see it actually throwing coolant everywhere?

 

[arad85]

Guys in the garage diagnosed it when they had the front off to fit a dual pulley system... See attached for symptoms

 

[meph137]

Guys in the garage diagnosed it when they had the front off to fit a dual pulley system... See attached for symptoms

Ah yeh so you can see the dispersal of it. Was it just a new pump? How much did that set you back?


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[arad85]

Had the front off anyway - about 300 from memory - 150 for bits I think plus a couple of hours labour. Car is "under warranty" but didn't bother with arguing with Audi as it has already been tuned and that's the first thing they'd reject this on.

Edit: yes, just new pump/seals and a rubber pipe.

 

[meph137]

Had the front off anyway - about 300 from memory - 150 for bits I think plus a couple of hours labour. Car is "under warranty" but didn't bother with arguing with Audi as it has already been tuned and that's the first thing they'd reject this on.

Edit: yes, just new pump/seals and a rubber pipe.

Nice one I’d heard older models had a plastic pump, did yours? I’ve not looked at mine but I don’t think it’s plastic. Apparently they failed a fair bit.


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[arad85]

No idea... Mine's a 2016 plate. Just told it was the water pump and it would cost £300 to repair. Needed to be done so...

 

[rum4mo]

These pictures do not show the water pump, just the supercharger and its pulley, the water pump and its pulley are over to the right hand side as you look into the engine bay. My car is a January 2011 build and it had an alloy pump body from new.

A bit annoying if reverting back to alloy pump bodies did not stop most of the earlyish life water pump failures though!

 

[meph137]

These pictures do not show the water pump, just the supercharger and its pulley, the water pump and its pulley are over to the right hand side as you look into the engine bay. My car is a January 2011 build and it had an alloy pump body from new.

I think the intention was to show the symptoms of a leaking water pump though, which seems to be a spattering of white as shown, which I assume is the pump flinging the coolant out and it hitting other parts in the vicinity.

No idea... Mine's a 2016 plate

A bit annoying if reverting back to alloy pump bodies did not stop most of the earlyish life water pump failures though!

Yeh this does sound annoying, mine's a 2013 and I'm annoyed that it may have failed, I'd be well miffed on a 2016!

Does anyone know who the OEM for the pump is? I've gone down the route of buying OEM for the suspension bits I'm about to fit and it saves a hell of a lot, not sure how much it would save for the pump but all other manufacturers seems to retail at about £25ish for a pump, I presume Audi will charge a lot more. And on that note, if the Audi pumps are so failure-prone, are people fitting pumps from a different manufacturer to avoid this issue?

 

[meph137]

Symptoms were a coolant leak that would take 1-3 months (1k miles/month) to drop from max to min

Just curious, how many coolant fillups did you go through? Mine is near min now and I'm worried it's all suddenly going to drain out silly I know! So I'm curious, if you filled it up 2 times or more and it seemed to get no worse (or not much worse) it at least gives me slightly more reassurance that I don't need to get it changed this instant, as I'd prefer to research the problem a bit rather than just handing it over to Audi or a garage and asking them to fix it. Wouldn't mind having a go myself although it seems you need to remove the supercharger, which sounds a bit involved.

 

[arad85]

Just curious, how many coolant fillups did you go through? Mine is near min now and I'm worried it's all suddenly going to drain out silly I know! So I'm curious, if you filled it up 2 times or more and it seemed to get no worse (or not much worse) it at least gives me slightly more reassurance that I don't need to get it changed this instant, as I'd prefer to research the problem a bit rather than just handing it over to Audi or a garage and asking them to fix it. Wouldn't mind having a go myself although it seems you need to remove the supercharger, which sounds a bit involved.

Noticed in July last year at a service, was fixed in November. Probably filled (between low and high water mark) twice. Didn't get any worse. Don't need to remove the supercharger - you can probably do it by putting the front end into service position...

 

[arad85]

I think the intention was to show the symptoms of a leaking water pump though, which seems to be a spattering of white as shown, which I assume is the pump flinging the coolant out and it hitting other parts in the vicinity.

That's exactly what the photos were designed to do. The white/pink spattering was the leak getting atomised on the spinning parts in the vicinity and going everywhere... I think they took the front of the car off to diagnose it (it was already off as it was having the lower pulley changed).

As to livid... I was meh... The car had already been tuned and I knew it was pay to play.

 

[rum4mo]

Right okay, my fault, I did not see the marking on the small pipes, until you mentioned it.

When you say white deposits on plastic covers, which ones exactly do you mean as anything higher up and “out” from where it is shown on these pictures could be from other leak sources I’m guessing.

 

[youngsyp]

As it's not been mentioned and there's a lot of discussion here about filling up the expansion tank, it's worth pointing out that it's just that - an expansion tank. The level shouldn't be at the 'Max' mark unless the coolant is at engine operating temperature and when it's not, it's likely to be anywhere between the 'Max' and 'Min' marker. Only if it dips below the 'Min' marker should it be topped up.
Both air temperature and atmospheric pressure will affect the level, so unless you're noticing a huge swing in level, it's nominal.

If this is obvious to you, ignore.

Paul

 

[Dippy]

Thread resurrections usually confuse me but this is a useful reminder. I have become complacent about checking mine so if it had succumbed to a small leak I wouldn't have noticed.

 

[scotty76]

Just to chime in mine still needs a little coolant maybe once a year. It's done this from new and has been checked 3 times by Audi over the years with no fault found.

 

[scotty76]

I raised it here https://www.audi-sport.net/xf/threads/coolant-loss-b8-5-s4.229588/

 

[jdp1962]

As it's not been mentioned and there's a lot of discussion here about filling up the expansion tank, it's worth pointing out that it's just that - an expansion tank. The level shouldn't be at the 'Max' mark unless the coolant is at engine operating temperature and when it's not, it's likely to be anywhere between the 'Max' and 'Min' marker. Only if it dips below the 'Min' marker should it be topped up.
Both air temperature and atmospheric pressure will affect the level, so unless you're noticing a huge swing in level, it's nominal.

If this is obvious to you, ignore.

Paul

That wasn't previously obvious to me, so thank you.

 

[scotty76]

That wasn't previously obvious to me, so thank you.

I'm having deja vu about the max marker...

https://www.audi-sport.net/xf/threads/coolant-loss-b8-5-s4.229588/#post-2421741

 

[meph137]

I think they took the front of the car off to diagnose it

I'm not familiar with how you change the lower pulley, when you say they took the front off, that's more than just putting it in the service position I assume?

When you say white deposits on plastic covers, which ones exactly do you mean as anything higher up and “out” from where it is shown on these pictures could be from other leak sources I’m guessing.

Mine was on the front lip of the front removable plastic cover. I also seem to have spattering as @arad85 pictured so I'm feeling pretty convinced I have a leak, coupled with the info below...

The level shouldn't be at the 'Max' mark unless the coolant is at engine operating temperature and when it's not, it's likely to be anywhere between the 'Max' and 'Min' marker. Only if it dips below the 'Min' marker should it be topped up.

Good point. I measured mine when cold twice, once it was about 40% between min and max, now 2 months later it's just above min. When hot it does expand significantly I've noticed, it goes from just above min to just above halfway between min and max.

I have become complacent about checking mine so if it had succumbed to a small leak I wouldn't have noticed.

As had I, I found this by deciding to start a little excel spreadsheet recording results of checks - I wasn't expecting to find anything out of the ordinary so I'm glad I started, even if it turns out to be nothing (I have a feeling it won't) then at least I know the "norms" of things.

I'm having deja vu about the max marker...

https://www.audi-sport.net/xf/threads/coolant-loss-b8-5-s4.229588/#post-2421741

From your other thread you said:

No fault found. They suspect an airlock from factory. Pressure tested fine

I was actually considering purchasing a pressure tester (you can get some for about £40) but I wasn't sure if it would cause leaks in pumps to be evident, I guess it would but having never used things such as this I wondered whether leaks in pumps only became evident when the pump was spinning, i.e. I wasn't sure if it is enough simply to apply pressure 15bar of pressure (or whatever the system is rated to) and look to see if it's spitting out the pump. Sounds like Audi thought it was a worthwhile test though so maybe my concerns aren't valid.