Cooling Suggestions

A6 All/ S6 All
#1

I know there are risers for the manifold that help with heat issues, but I would really like to try some type of coolant system clean, a flush and maybe a 60/40 h20/g13 and see what happens. Right now my fans come on with just a little city driving and I’ve seen heat coming from the hood at times. Driving conditions have been pretty mild and temps are lower than that high 60’s F and even on cool days the fan always manages it’s way on. It’s too hot for my liking.

The previous owner had the rad replaced by the dealer about 7k ago. To me the coolant looks a little dirty and could stand to be renewed; it wouldn’t surprise me if they didn’t flush the entire system when the rad was replaced, but can’t imagine they wouldn’t.

Any thoughts, suggestions would be appreciated. Does anyone have the elsawin page for the flush? Should be easy if I can find the drain…

Anyone used a flush like this? https://www.ecstuning.com/Audi-C6_S6--V10_5.2L/Engine/Cooling/ES2608077/

Thx !

#2

The JHM intake spacers greatly reduce the intake temps and if you do the thorttle bypass it will help drop that as well.

There is no need to get that flush fluid. Just drain the fluid and replace the fluid with G13 G12 dosent pull out as much heat as G13 coolant.

The intake spacers are something you should really consider they do a great job and youll be able to tell a big difference. They will also help keep those gaskets around your oil filter from getting bad.

When you do the fluid flush drain your coolant fluid and check your rad units for debris. spray them down to make sure nothing is clogging up the fins. If you have debris in the rad unit it wont cool as well.

So getting the JHM spacers and switching from G12 to G13 will help bring down the temps a little. Keep in mind that you have a termostat that controls coolant temps so there is only so much you can do there.

#3

Maybe your thermostat isn’t opening when it should or not all the way. These german cars run hot. My old s4 could heat the garage just by being parked in there. Cooks your feet too.

Changing the fluid would help and a flush wouldnt hurt but in my opinipn it’s easier just to drain as much as you can from the radiator and block and then just fill it again. If after a week or so the fluid doesn’t look clean then change it again.

#4

These cars run hot, and the fan comes on very quickly which I actually like. Now, I drove my s6 very hard e.g melted the logos off the top of the motor, but never once did my temp gauge move right of center which impressed the hell out of me. Bottom line is hey are built to run relatively hot and are ok. That said heat soak eventually kills components and performance always takes a hit. IM spacers are a must. Installing headers and relocating the microwaves aka cats further down the exhaust path away from everything else or removing totally helps with heat. Perhaps you half an rig up a bigger fan or cooling system but I’d retry what I recommend first. Changing cooling type i am not confident you will notice any difference.

Btw if you think the fan kicks on prematurely go drive a v10 m5 that fan kicks on and stays on almost all the time and the temp gauge will rise, what’s interesting is that car had almost no heat soak so see how BMW did it. I imagine more physical cooling design within the engine bay and larger fan?

#5

Probably a dumb question, but what’s stopping us from replacing the thermostat with one that keeps the coolant temps a little lower?

#6

You can do that but the car will never come out of warm up mode. The JHM tune generally lowers motor and oil temps but on the V10s I dont know enough about what they might or might not do. best to be a question to ask

#7

Good point. So if you could reprogram it so it leaves warmup mode at a lower temp, and then replace the thermostat with a lower-temp version, you could potentially have a much cooler engine right? I must be missing something, that sounds way too easy.

#8

The programing part is difficult to start with.

Then you have the part where the motor is all aluminum so you have to make sure its not too cool. The big issue on why the motors get so hot is that the motor needs to be hotter then the piston as the piston expands. If the block is cooler then the piston the pistion will expand and score the cylinders

#9

Makes sense… so it’s better to focus on cooling everything else down, particularly the intake system, while allowing the engine to stay roughly the same temp

#10

Yes the JHM intake spacers drasticly reduce the intake temps and that means lower air temps going into the motor. The long runner of the intake is well over 3 feet long so that is more then enough time to super heat the air.

The JHM tune most people like because they do what no other company does and thats actually work to cool the block down slightly in the tune. You dont need a thermostat for that but its helpful and good for the long term health of the motor.

#11

Sounds right

#12

Thanks for all the great replies guys. I’ll let you know how things change after the g13. One day I’ll do the spacers.

The only thing I still can’t figure out (since I don’t have a an manual yet!) is the easiest location to drain the coolant. I’m assuming lower fitting to the rad? Thx !

#13

It is eather the red cap on the rad itself or you can find a drain allen bit on the water pump neck I believe.

#14

I removed the “engine blanket” and it seems to have helped slightly. Bentley manual is coming in the mail so I can perform the flush. Temped in the meantime to top off with water. It’s fine really; needle never moves past half. 4th gear is a monster!

#15

I probably missed it, but What do you mean by engine blanket? Get the spacers you will thank us later :slight_smile:

#16

Seems like the spacers are a no-brainer price, benefit. I just need to feel comfortable with doing the work in the garage myself - which seems not too bad. I haven’t pulled a manifold yet.

Engine blanket meaning the hood liner.

#17

Ah I was thinking about exhaust wrap.

Get the spacers and do a carbon clean at the same time.