Coolant change in C5 RS6?

[Shoppinit]

Interesting VIN there. Car wasn't made for the European market by the look of it.

[C5RS6ABT]

No it was not made for European market originally. It's a Saudi Arabia model - I used to live in UAE (like mentioned in my previous post) and the car is originally from UAE. I would assume that all GCC (Gulf co-operation council) got the same model back in the days.

Interesting VIN there. Car wasn't made for the European market by the look of it.

[Shoppinit]

Any luck with your coolant change?

[C5RS6ABT]

Got my (rented) garage for the cars available just last week so this will be done within the next few days. Tester showed that the coolant is good for around -10 -12 degrees centigrade so it has to be changed before really cold climate starts to kick in >(in FIN)

Any luck with your coolant change?

[mik15]

how did you do about shipping the cars to Europe? i was planning to take this one back to Germany...as far as i know the RS6 made for the GCC are Euro2, any issues in registering the car in Fin ? How much did it cost/car and how long did it take? I would really appreciate some info on this !

[C5RS6ABT]

Hey mik15,

40ft container and my car + a car of my mate. Took around 6-weeks from UAE to FIN. I need to check the cost from my other PC but I will not recommend the company I used. You can check one thead in Dubai Petrolheads forum about this particular incident. Still going on...

No issues whatsoever registering the car in FIN. If You want I can email the docs to You. However, bear in mind that we may/migh/and most likely will have different regulations to any other country in EU That being said if a car can be registered in FIN..it most likely will get registered anywhere else in EU. (do not quote me on this)

how did you do about shipping the cars to Europe? i was planning to take this one back to Germany...as far as i know the RS6 made for the GCC are Euro2, any issues in registering the car in Fin ? How much did it cost/car and how long did it take? I would really appreciate some info on this !

[Mr Footlong]

Hi guys.

Sorry to drag this one back up, but when doing the last periodic fuse 29-removed cranking over of my car to lubricate the bores and then a proper fire up and run, I noticed that the coolant level in the expansion tank was low. It continued to go down and at that point I turned her off, removed fuse 29 again and went about my day. This was back in late October.

Checking her over again this week I found that the expansion tank was totally empty, so have only done a bore lubing crankover and not fired her up. When I removed the scuttle to check over, I noticed the pipework from what I assume to be the heater matrix looking like this -

Note the right pipe especially. It is still partly on as the barbs are quite long. Sadly I think it is a stretch to hope that the coolant leak is coming from there due to the height, but of course I didn't know about it when the scuttle was on and possibly the pressurised system as the engine was warming could have been pushing the water out of there.

Anyway, waffling. Regardless of that, I want to refill the system, jack the front to get her level and have a look underneath with the tray off. It is a sloped drive with drainage just in front of the car, so I had no visible idea of when/that she was even leaking.

Regarding the one-way/bleed valve that is mentioned at the beginning of this thread and it being located "in the heater", are we talking about the heater matrix pictured above, or somewhere else? Thanks for your time .

[Shoppinit]

To bleed you pull one of those heater matrix pipes partially to expose a small bleed hole. Can't remember which one. I've never needed to bleed mine, even after draining the coolant.

Like you, I also think it's unlikely this is the source of your leak, although if the system isn't pressurised properly you can lose coolant through boiling / evaporation. Depends how long you were running it for. Maybe you're like me and start it to warm it up then go off and do something else only to remember an hour later that you left the car running.

Usually it's the stoopid plastic pipe in the oil filter housing that causes this kind of fluid loss.

You could also check for fluid under the carpet in case the heater is leaking.

I thought you had sold this car.

[Mr Footlong]

Nope, not advertised as up for sale yet and still struggling to bring myself to part with her, so she continues to sit on the drive. Someone does have first refusal on her though and I have messed him around a bit with indecision and heartstrings being tugged with over 11 years of ownership.....

I ran her for a good 30 mins, but I was outside and by the car while doing this, so I noticed as soon as she complained about low coolant. I filled up the expansion tank, but it continued to drop, turned her off.

For the amount of coolant missing from the tank, if it was the matrix I would expect to feel that amount of water through the carpets without lifting them (already checked that, but I will do that once the weather permits.

I heard talk about a pipe that snakes around the back of the engine being a strong culprit (engine out job?), but I have no clue about the oil filter housing one, do you think that is something in my skillset to replace if I find it is that? Cheers.

[Shoppinit]

This recent thread mentions it:

viewtopic.php?f=2&t=143441

Could be the pipe around the back of the engine. Better hope not. It's not very likely I think.

Could be the seal on the coolant temp sender (which is located on the pipe in question).

The carpet underlay is so thick that you'd probably not feel any wetness on the surface of the carpet unless there were litres of it.

[Mɐʇʇ]

I heard talk about a pipe that snakes around the back of the engine being a strong culprit (engine out job?), but I have no clue about the oil filter housing one, do you think that is something in my skillset to replace if I find it is that? Cheers.

Yes, this pipe can corrode. But based on what you've shared about jobs the car needs (turbos & box), I'd recommend any buyer just gives it a good going over which'll include engine out, and then do all the big jobs in one go. Easier that way. Bufkin pipe, gear selector switch, EGT sensors - just give them all a good check & refresh while the gearbox and turbos (I think I remember you said they need refreshing?) are being done. You'd be on a hiding to nowhere to replace that pipe but then not do the other engine our jobs at the same time. However, just for sanity sake, shine a torch vertically down the OS rear of the of the filter box. You can see the black "snake" pipe there - and it has a bolt on the top of it. If that bolt comes loose, you loose coolant, it's one of the bleed points, generally it's the one that needs doing. The heater bleed point (which is behind the scuttle panel, just inboard of the coolant header tank) rarely needs touching.

Also then shine torch, still on the rear of the airbox, but on the near side. That's the main temperature sensor, which again, can corrode a bit around and leak. If the leak is there, it's fiddly, but doable to do in-situ.

[Mr Footlong]

Guys, thanks, really appreciated. Matt, I will have a look at those usual suspect areas as soon as the weather really allows it, great info !

Turbos are ok, just a bit tired, they haven't failed. I reckon the oil seals are getting tired as when the engine is left for a good period of time and you start her up, there is a little bit of smoke for say the first 30 secs or so but as heat builds this disappears if memory serves.

[Mɐʇʇ]

Absolutely, I checked back on your earlier thread on your "to do" list. It just really is a case of, if you're pulling the engine out for a few jobs, do ALL the jobs in one go and freshen everything right up to be spot on.

[Mr Footlong]

Lol, no argument there at all. I had detailed talks with RD in Shepperton back in 2020 regarding pulling the lump, removing the gearbox so I could get that rebuilt/uprated at the same time, uprated turbos and everything that we could realistically replace, being replaced. I was all for it, but had such a royal sh!t of time getting someone decent to do the gearbox/TC work done that I put it on the backburner sadly. Various things happened in life and here we are.

[Mr Footlong]

Ok, I would have probably never found that bleed hole in a million years myself, cheers Matt.

Shopp, I lifted the front passenger side carpet, bone dry underneath, ECU is fine. I haven't lifted the driver side, do you reckon I need to? I assume if the heater matrix had failed, there is no guarantee that it would only soak the passenger side. Sod it, I will lift the driver side in a bit.

I tried pulling off the already lifted heater matrix pipe, but with there being some flex built into the barbs, I wasn't happy with applying too much force to what feels like semi-loose pipework through the firewall to the matrix. Opened up the expansion tank, then opened the bleed valve. Lovely pink coolant gushed out, so I quickly closed that back up, didn't leave it for long enough to see if the tank level started to drop. Obvious thing to do is to open that valve again with the tank cap closed, non?

If memory serves, when I noticed that the coolant level was dropping back on the October fire-up and driveway idle run, I think I wasn't getting any heat passing through into the cabin (normally cranked the heat up on AC to help dehumidify). I think that may have prompted me to pop the bonnet and look at the expansion tank etc., I just can't remember.

Bouyed on by the coolant pouring out of the bleed valve, I connected the battery, gave her a quick bore lube crank and then stuck fuse 29 back in. I fired her up, started on a dime as she does and let her run for 60-90 secs. Didn't notice the coolant level drop in that short time, but could that be related to the thermostat being closed? Not terribly knowledgeable there...

Is the next step for me to stick her up on stands, whip the tray off and see what I can see? The only problem with that is my stupid heart problem gives me direct troubles when on my back, makes it difficult to work on the floor. Otherwise, it would be a case of booking her into the garage 1/2 a mile up the road and risking driving her up there for them to take a look?

Thanks