Epic Moring - W202 overheated

[FunkMasterJay]

Hello all.

What an epic morning.

I was driving to work, and after a mile of so I wondered why my heater was still blowing cold. I quickly glanced at my temp gauge and it was 3/4 so I stopped, and let it cool down just before I hit the M25. I waited about half hour, started, and drove back to London road closer to civilisation.

I parked, called RAC and bought some water / anti freeze.

I topped up before the guy got there, but he followed me to a local garage.

They tried to say my head gasket was gone etc as there was oil, but I insisted to replace the thermostat and flush the coolant first, and if that failed then we would consider the other option.

Long story short, coolant was flushed and there was crap in the reservoir. New stat fitted, coolant topped up and 25 miles later so far so good. But why am I still panicking. Heater works, and temp needle now sits just above 80. I have been on A and M roads since with no issues, but my worry is why today and all of a sudden.

Any ideas?

Jason.

 

[st13phil]

...but my worry is why today and all of a sudden.

Any ideas?

In really cold conditions it's possible for the bottom of the radiator to freeze even with a good antifreeze concentration. By stopping for a while residual heat would allow it to thaw and then the cooling system will work normally again.

Of course, it could be the head gasket...

 

[FunkMasterJay]

Thanks Phil.
Sorry I don't have experience with these cars. Surely if it was the head gasket, I would have broken down again by now.

The guy that changed the coolant said there was no oil, but just built up crap.

Any more tell tale signs?

Thanks again.

Jason.

 

[st13phil]

The absence of oil in the water is encouraging, but not definitive. I would expect that whoever changed the thermostat & coolant would also have checked for signs of water in the oil if they suspected a head gasket, so the absence of any obvious problems in that respect is more good news.

Personally, at this stage, I'd be inclined to put it down to exceptionally cold conditions and perhaps a low antifreeze concentration. I'd just keep an eye on the temperature gauge and check the fluid levels regularly. Unless it loses water I wouldn't worry too much.

 

[FunkMasterJay]

Cheers Phil.

I am in the office now, but will have another look at the tank now it has cooled down and if it has dropped again, I will put it down to a bad radiator... assuming oil is fine.

I'm just used to the gauge being dead on 80, but i'm assuming with the new thermostat it might change slightly. It's currently JUST above 80.

Panic over....for now. Thanks MUCHLY.