kkkk

I have an early 2010 C63. When I started the car today, the "Top up coolant" warning came on. I immediately turned the car off
Now I have read all about headbolt issues, but I do tend to think the worst in most cases.
I do not think there was any white smoke.

What are my next steps?
Top up the coolant, and see if the message comes back again?
Pressurise the system and see if I can find a leak?
Drop the oil and see if there is any coolant in the oil?

Is the car still safe to drive?

SGM330

Topping up coolant and doing a pressure test would be the cheapest and easiest options to start off from. Do this first before you drive

kkkk

OK, the coolant has only dropped about 150mL , so we topped it up. Pressure test held 15psi for over an hour
The radiator cap has a slight leak, and the radiator has a minor leak too. Im quite disappointed that I need a new radiator on a 8 year old car.

Jasonoff

What level will your disappointment be if your HBs fail?

Funkwagen

Be very happy it's just a rad and not a head bolt issue. My heart sunk when I got that warning on my dash, but it was only due to the sudden cold weather. I get this warning every year when there's a significant drop in temperature, in both the C63 and C250. Neither ever really need topping up

skullbox15

Seriously! consider yourself lucky.

kkkk

What is the OEM replacement for a radiator? I can get a BEHR Hella radiator. Would this work or should I stick with genuine mercedes?

kkkk

Just got this message again after 4 months. Iv changed the headbolts and new radiator too.

PeterA90

If you did the headbolts then that rules that out. Check the entire cooling system. The cars hoses are brittle after tons of heat cycles. Hopefully you used a
genuine Mercedes radiator. Cheap route sometimes costs more in the end.

BLKROKT

Behr is the OE radiator manufacturer

Yuille36

kkkk,

For peace of mind, check your oil to ensure that it's only oil and not mixed with engine coolant.
That would rule out broken head bolts, and coolant contamination.

BalanBro

True. Send out an oil sample to be analyzed for coolant just to be sure.

Jasonoff

It's 100x easier to do a combustion leak test. I did this before replacing my headbolts one at a time just to verify the HG wasn't compromised.

kkkk

Is a chemical test like that better than doing a pressure test ?