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Hello everyone, I am new to the MB forums. I recently purchashed a used 2003 C320 with 159k miles on it. Everything seems fine but I am concerned about the temprature it seems a bit high, especially when in traffic or city driving. Is this normal?
Last edited by Jeffrey320; 12-16-2015 at 02:19 AM.
It's maybe few degrees hotter than mine, but there can be gauge and sensor could be inaccurate. With that many miles and not knowing its history of maintenance I would fully flush it and examine the radiator core to see if it's corroded , reducing cooling. Replace thermostat and at that mileage hoses, and check the fans operate correctly. Can you see into the radiator from the cap? ( many you can't ) Today you could hose off and clean the radiator, maybe it's dirty reducing cooling. If radiator is visibly dirty spray it with soap first and try to wash it with decent water pressure. Not super high pressure unless your careful. If it was running real hot the pressure relief would open filling the expansion tank to maybe overflowing
Replace the thermostat , running it cold isnt good for motor oil, colder oil can start sludging up. Also the fuel injection may run a bit rich, the computer might think it's still warming up. Also make sure the cooling fan isn't coming on. The fans hardly ever run in winter.
Running a motor that hasn't warmed up for long periods is bad for motor oil. Oil needs to reach operating temp to cook out the blowby gasses and moisture. Your PVC system recirculates those gasses to keep the oil from deteriorating and turning to sludge. Running below about 180f is where the oil isn't warm enough to cook out contaminants. If you drive a few miles a day at 0f your oil will never heat up and you oil can be trash in 1000- 1500 miles, or with a fan locked on or a bad thermostat will not allow the motor to warm up. I had a good thermostat , drove an hour at a time but the fan was stuck on and it ruined my PVC system, clogging it shut and clogging the turbo oil line. Yes replace the thermostat and a genuine mb part is better than Chinese parts that are not made the same. Have your pvc system checked out and look for signs of sludging. Sludge will ruin a motor with no fix, running a bit hot with antifreeze that doesn't boil till 260f won't ruin anything. I see the outdoor temp on your car showed 54, if that's as cold as it gets at night and you drive 45 min to an hour at a time you should be ok. I warm up in 5-10 minutes to operating temp even at 20f outside, if it takes you like 30 minutes to warm up the thermostat is stuck open and that's real bad. A motor needs heat to decontaminate oil.
Thank you for the pvc reminder. That is another place that I now intend to check/replace. I learned that a clogged pvc can cause an engine to run rich? Furtunatly I am an apprentice at a shop and have access to equipment. Any advice on recommended relairs would be greatly appreciated.
12-15-2015, 06:21 PM
