George993

hi, in a process of fixing leaking turbos I'm trying to drain the main engine radiator. There is a plug/valve at the bottom of the radiator (driver side in US) with a nipple for coolant hose below it. Car is full of coolant, reservoir cap removed.

The valve (plastic with a flap which can be rotated by hand) has 45 degrees movement. I rotate it from one end to the other in that 45 degrees, coolant does not drain. Is that plastic part just a valve cover I should push out to find a valve below or is there anything else needed to be done to drain the radiator?

thanks!

konigstiger

WIS...

Nickthegreek

Also be careful when refilling the system. At the dealership they use a vacuum filler to fill the turbos. You do not want air in the turbos

alx

i believe the ic coolant system is independent. it was shared with the engine coolant for the 55 kompressor cars, but for the v12tt it is a separate circuit.

WHPH28

That is correct. The cooling system for the turbos and intercooler is separate from the engine cooling system in the S600.

Nickthegreek

Is it run from an auxiliary electric pump and have its own reservoir. Gonna check it out. The V12 is a whole different beast than the V8. And a hell of alot harder to service on your own. A friend of mine who worked at the dealership told me not to buy one with a V12 because of this.

alx

They all say that. I have an sl65 which has been a peach to maintain. Abc and coils are the only thing that goes wrong with them. Both are well within your skill set. Not having the skill to work on it? The v12tt will eat you alive at the dealer.

The v12tt cars are the hidden awesome deal in the Amg lineup for our kind of owners

Nickthegreek

i always get the temptation to buy one too.... lmao

WHPH28

There is nothing like the V12 TT honestly...completely different animal from the V8.

Every high end luxury car you hear the same thing... people say don't buy this or don't buy that...I think it's because they are scared/can't work on it, or it's one of those word of mouth things that gets worse and worse as people tell it.

If I believed that, I would be driving a ford focus.

As for the dealer, yes, their book rate will take your $$$.

George993

hi, here is an update. I did change the top turbo seals myself, not very complicated but very time consuming. Requires removal of ignition cassettes and many other parts, project lasted several days. No leaks 4 months later. Considering the coolant direction (from bottom to top) bottom seals will last much longer so I don't feel bad about not changing them. But if you get the same problem and if you find a mechanic who can do the top seals for less than $1000 just save yourself time and let him do it. I could not find one - independent shops just did not want to touch the car or like the dealer wanted to do the complete engine-out job. Passenger (USA) side is much much easier. I changed both sides, it is hard to say which one is leaking - there is enough parts below to spread the leak to appear on both sides even if only one is leaking. In any case it makes sense to change both as they will have similar life span. You will also need to change the seals in turbo oil pipes as they use the same mounting. Use brass equipment (I'm using Parker Seal) to remove/install/clear the coolant seals to avoid scratches and leaks. I also did not drain coolant completely, just disconnected a pipe near radiator top and siphoned coolant out to the turbo level. Plus I siphoned a bit more coolant from the turbos directly - just enough to have a dry surface for seals, but leaving the rest of coolant inside just in case you really need to prime them with coolant before starting. Also I know now where the burnt m275 engines come from - the fuel line (driver side, which you need to disconnect in the process) just slides on without any fasteners and probably slides out by itself sometimes causing fuel spill and fire - I've fastened it properly to avoid future problems.

George993

and BTW - turbos are being cooled from the same system as the engine (using front radiator). Because turbos are very hot, the seals in turbos fail and leak. It is the turbo air inlet (intercooler) which has a separate cooling circuit - the one in the back behind the engine. But intercooler coolant circuit is low temperature and should rarely if ever leak.