I have a water leak from the thermostat housing on my 2009 R56. I usually just top up the reservoir every month. The reservoir got low and the temperature and oil indicator came on. I heard a knocking noise from the engine and pulled over and let the car cool down. I filled up the reservoir and drove it home. The oil level was ok.


After the car cooled off, I attached my code reader and got the following codes: P0503, P1776 and P1777.


I reset the check engine light and will check tomorrow if the light comes back on.


Is there any damage I might have done to the car? I am not sure if the codes are related to the low water level or damaged thermostat housing or something else.

 

A knocking noise inside the engine can be minor, but it's usually some engine component in trouble...up to and including parts that would require a major engine rebuild.

I would not run it further than it takes to get it it to an expert for a diagnosis.

 

How was the color of the oil on the dipstick?

 

So you have run with a coolant leak for a while, and you overheated the engine and lost oil pressure. That's never a good thing--neither the overheating, nor the losing pressure.

I figure the chances are decent that you did some damage. How much damage is the question. The worst case is that the bottom end is now damaged and the head is warped. The best case is that there is extra wear on the wear parts. I strongly recommend you have an expert look it over...

 

Yup...two things that say "pull over NOW and shut the engine off"....

Overheating or loss of oil pressure.

 

+1

And I know my question is very stupid:

Why you have not replaced the broken thermostat since there was a leak on it?