Failed Oil Cooler and other coolant problems - Do I get rid?

[Samk87]

Hi All,
I have a 2013 C220 (70K miles) that has cost me a fortune since Christmas with various different repairs. Recently it overheated, went into limp mode, I had a tow to the garage, and ended up replacing the thermostat and a couple of sensors - not a huge problem as this was less than £500.
A few weeks later though I noticed the header tank full of oil, so took it back in. They diagnosed a failed oil cooler, and replaced it, along with a new water pump, oil filter housing gasket, and fuel filter housing. It was flushed through a few times to try and get all the oil out, and only a tiny amount remains in the header tank - too small an amount to syringe out. I've kept an eye on the dipstick and can't see any mayonaissy stuff on it, so am not too worried yet about the head gasket.
I'm sure that the oil cooler failed due to overheating when the thermostat wasn't working properly - but my worry now is whether this is going to be an ongoing issue, and should I just get rid of the car before this problem reappears, and something else was damaged when it overheated?
Obviously nobody has a crystal ball, but would the general opinion be to get rid and buy something cheaper, or to keep an eye on the header tank and dipstick and hope for the best?
The other thing I've noticed is the temperature gauge coming down by about 10 degrees when I come off the motorway. Is this normal?
Many thanks for any advice or opinions.

 

[Tuercas viejas]

Hi All,
I have a 2013 C220 (70K miles) that has cost me a fortune since Christmas with various different repairs. Recently it overheated, went into limp mode, I had a tow to the garage, and ended up replacing the thermostat and a couple of sensors - not a huge problem as this was less than £500.
A few weeks later though I noticed the header tank full of oil, so took it back in. They diagnosed a failed oil cooler, and replaced it, along with a new water pump, oil filter housing gasket, and fuel filter housing. It was flushed through a few times to try and get all the oil out, and only a tiny amount remains in the header tank - too small an amount to syringe out. I've kept an eye on the dipstick and can't see any mayonaissy stuff on it, so am not too worried yet about the head gasket.
I'm sure that the oil cooler failed due to overheating when the thermostat wasn't working properly - but my worry now is whether this is going to be an ongoing issue, and should I just get rid of the car before this problem reappears, and something else was damaged when it overheated?
Obviously nobody has a crystal ball, but would the general opinion be to get rid and buy something cheaper, or to keep an eye on the header tank and dipstick and hope for the best?
The other thing I've noticed is the temperature gauge coming down by about 10 degrees when I come off the motorway. Is this normal?
Many thanks for any advice or opinions.

To rid the cooling system of ALL oil deposits, the simplest method is to drain the cooling system and fill with fresh water , Then add two sachets or the same amount of dishwasher detergent into the radiator.
Then drive it a few time repeating the clean out a few times .
Works great on OM647 /OM612's and the low surfactant content of the detergent will "Fairy" its way into every nook and cranny in the cooling system cleaning it .
Once clean, & an additional water flush, then add a good A/F pre-mix & drive the wheels off of it , AND stop sweating the small stuff!

Over here its called Dawn, great idea when it "dawned" on me!
And surfactant isn't a member of the King Art's Round Table either!
Tuercas Viejas

 

[E55BOF]

Oil is less dense than water, so it floats on water. Apart from 'mayonnaise', it does not mix with water (and techically, even mayonnaise isn't mixed, it's just in suspension in tiny droplets), so any left in the cooling system will float to the highest point in that system - the header tank. If there's only a minute amount showing there, syphon out any you can, and unless mayonnaise starts appearing, don't worry about it.

The temperature gauge should sit at 90 degrees all the time once the engine is fully warmed up; anything less and you may well have a thermostat beginning to give up the ghost. It should not drop at all when you come off the motorway, unless you've been caning it on a hot day and the temperature has risen above normal because of that.