SilverBulletE63

So I just bought my first AMG (and first Merc, I've been a BMW guy all my life) yesterday, a 2009 E63. I love the car and it runs fantastic! After cruising around Nashville and driving some backroads to the interstate, I got a "top off coolant" message and immediately stopped off to buy coolant and fill it up. Had been driving the car for about 1 1/2 to 2 hours by this point, and got another "top off coolant" message about 2 to 2 1/2 hours later of interstate driving. Checked the car out twice before buying and there was nothing on the ground, just a tad leaking out of the reservoir cap. This morning, under further inspection after a short drive and another top off, there was coolant covering the belly pan on both sides of the engine and in front of the engine, inside the drivers wheel well, splashed onto the driver side door and side skirt, on front driver side suspension components, driver side header, spray under expansion tank, and the sides and bottom of the tank were soaked in coolant.

This made me think it was the reservoir so I dried it off best I could, let it sit for a while, took it for another short drive, and checked again. TANK WAS BONE DRY with the exception of a little bit coming out of the cap. I didn't drive as hard as I did this morning so I don't know if that makes a difference. But, I am also experiencing an intermittent heater. Yesterday it took a long time for the heat to kick in, switched to AC eventually once it got warmer outside, then back to heat and again took forever to warm up. This morning after driving for about 15-20 minutes the heat never came on. Any help on these issues would be greatly appreciated, thanks!

shadymilkman

Sigh. Park the car, have the head inspected - you might have bought someones headbolt elses issue, a known problem with this model year M156.

SilverBulletE63

I was afraid of that but it is showing no other symptoms, oil has no coolant in it, no smoke from the exhaust, no coolant on the block, no power loss, nothing. I got a new coolant tank that I'm going to install shortly, I'll post an update. If this doesn't solve my issues of coolant loss I will have the head checked out, I am going to be ordering head bolts soon anyway as preventative maintenance.

machild

If you have coolant in the belly pans then some if not all of the lost coolant is leaking out of the coolant system. You need to pressure test the coolant system when the engine is not hot and see where it is leaking make repairs and then see what if there are any other issues. Good luck.

SilverBulletE63

Thanks for the advice, probably going to take it to a shop for diag

SilverBulletE63

UPDATE: I replaced the expansion tank and drove it around for a while, all seemed well until I got on it a bit and it blew the cap off the new tank. Cap was also brand new (came with the tank). The car didn’t over heat or rise in temp much at all because I was so close to home when it happened I was able to pull in and stop the car almost immediately. The cars temps were perfect and steady before this happened and only raised 2 bars on the gauge before I shut it off. Still blowing cold air when temp is set to high and AC turned off…

Guess I’m taking it to a shop to be thoroughly looked over. Expansion tank was my guess for the coolant loss, but it’s starting to look like excess pressure from somewhere in the system maybe?

machild

Sounds like head bolts may be compromised and that is allowing compression gases to leak into the coolant system. As originally mentioned, you may in fact, have acquired the previous owner's burden.

SilverBulletE63

Could that head bolt issue be causing the fault in the heater as well?

Hokanato

Yes, because almost every head gasket problem involves the heater in part.

Rovel

I'd say don't panic but have someone diagnose it. Since you're losing that much coolant I'd assume your oil would be all milky if it was head bolts.

SilverBulletE63

It is currently at a local Indy shop waiting to be diagnosed. That's what I thought too, having to top off coolant twice on the way back from Nashville, if it was the head bolts I would think the oil/coolant would be a milkshake by now but they're both clean....

bbirdwell

On a different car I once owned, a warped head allowed combustion chamber pressure to blow coolant out but did not allow coolant into the oil. So...no coolant in oil does not mean no broken head bolts (which allows the head to lift).
EDIT: the compression leak would blow the cap off of the reservoir followed by all of the coolant. I was fortunate I did not blow the engine.