Date registered: Sep 2013
Vehicle: 300 SDL
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1986 300 SDL Overheating - gasket, cylinder block, pump??
3 days ago I noticed on arriving home the engine temp at 110C. Checked and the coolant was low. Drove it again yesterday it heats up to 110 after about 10 minutes on flat grade. Both the rad and the reservoir get hot so it's not a stuck thermostat and maybe not water pump as fluid is circulating . Leaks about 2-3 quarts of fluid after 10 minutes drive. Coolant is visible in quantity in the pan under the engine. Can't see if its leaking from the water pump, but I notice the exhaust seems to now have a fair amount of white smoke. This worries me as I had total engine overhaul 2 years ago at high cost. The radiator is brand new Behr. I looked in the oil filler cap and there's no white gunk there, neither on the dipstick. Is it possible it's a blown head gasket or cracked cylinder head even if there's no sign of water getting in the oil? Are there different symptoms for blown head gasket vs cracked cylinder block?? Is replacing the head gasket an expensive job? What else could it be, assuming the white smoke indicates coolant burning off?
Another thing, the heater doesn't work at all now. I replaced the monovalve 5 years ago, but last year the heat became intermittent.
1986 300SDL 166K miles