Hey Gentlemen and Gals,

Since it’s been so long since my last post I will offer my car info. 2015 E63s W212 AMG Heavily tuned (E50), full 100% Meth Injection-and other mods.

So this morning while having some fun roll racing with a Lambo on local freeway, I developed a coolant leak that seems to behind the motor somewhere. It’s a significant leak. Barely made it home without coolant going too low. The entire engine bay seems clear of leaks. The obvious following was ruled out both by inspection and the fact that they were all replaced within the last 2 years:

water pump
thermostat housing
aux tank
turbo lines
radiator
all lines/hoses to and from radiator.

Leak is dripping from mid under belly cover lip that mostly covers tranny. Engine cover front belly pan is entirely dry. Front of motor is entirely dry. (The inspection I mentioned above)

I have refilled the coolant system that took took about 3/4 gallon. I started it cold and it does not seem to leak at idle. But if I drive it to full temp and pressure it really starts leaking. So it’s a seal giving out under pressure.

BIG COINCIDENCE: I used the heater on the car for the first time in a while this morning, and it was shortly after this combined with going full stage 3 throttle with meth spray that the leak started.

ChatGPT tells me it is most likely an o-ring between metal line and rubber hose in the heater circuit located between the firewall and rear of block. Says it can be repaired without dropping motor. Says it’s tight but experienced Indies can do it.

It is NOT the heater core as there is no coolant odor or steam in the cabin.

SO MY QUESTION after all that 😁:

Any of you guys ever have to deal with heater coolant circuit that can offer some idea of what I am in for?

Thanks in Advance!

 

Likely the heater "valve" in the rear driver side of the engine. . It's a known cause of issue. It's not a really a valve but a bushing/coupling. Cheap parts with lots of labor. It could also be the one at the firewall. This can be done without removing the intake (that the book calls for) by removing the false firewall at the rear of the engine. a few recent threads on this repair. I just had the one at the block replaced. Oldman just did these. Legit Street Cars just had one blow on the dyno on the most recent video but they dont show the repair. About five hours of *****ing ahead, or 3k plus at a dealer with intake off.

 

Thanks man. I think you’re right on point. My Indie over the phone said it’s likely the plastic fitting connected to the heater hose behind the driver’s side head. This shop is really good here in San Jose. They are fairly good size, they only work on Mercedes and most of their techs are former dealer AMG certified guys.

They confirmed it’s fairly common on these cars. Their quote seemed really fare at $930. I bet my dealership would have tried telling me around $2,500! Damn stealers. Ugh.

I couldn’t get an appointment until Feb 5th. Gonna drive my truck snd leave car in garage on trickle charger until then and drive straight to the shop after commute time with a couple extra gallons of distilled water in the back and stare at my temp gauge. 😁

I’ll update the final findings after it’s officially diagnosed a day or two after Feb 5th.

Thanks again for chiming in!

Cheers.

 

Sounds like you will get it taken care of. A grand isn’t bad. They’re not taking off the intake for that but going in the “quicker “way. Dealer takes off the intake. That’s why it’s over three grand going that way. If you were to take off the intake now would be the time for walnuts.

 

I can track down my thread...I had the exaxct issue. The key was to take out the "fake firewall" so gain access to the rear of the engine. Back there were a couple hoses...my leak specifically was from the temp sensor at the rear of the engine.

Coming full circle - the root cause of all of my cooling issues was a clogged radiator...(another thread).

https://mbworld.org/forums/w212-amg/...m_content=post

 

ah, I didn’t see your result was radiator…. I “think” I proactively had changed mine when I got the car in 19..

 

After months...and in the past two the root cause was the radiator...another thread with some good images of the radiator cut apart

 

Actually had read that thread. I accidentally thought I was talking to RVA;/. Long days...

 

Hello all,

I recently addressed this issue on my '14 E63S Estate

I suggest you ask your shop to evaluate/replace your vacuum pump while they are in there, (they'll need to move it for access on this job). In my case, when I turned the vacuum pump "impeller" (thing that spins inside) a significant amount of oil barfed out indicating the vacuum pump had begun to fail. Since they have several failure issues with these pumps (the vacuum valves perish) myself would simply have the shop install a replacement, no add'l labor involved

 

can I ask if you were aware and proactively replaced the valve on the pump?