I gave my 300 SD a hard run this afternoon to clear out the engine, when I got it home I poped the hood and noticed some bubbles in the overflow tank, and the coolant was lower than normal, once I shut the car down the coolant level returned to hot normal, I let the car sit for about a half hour started it again and I did not see any bubbles? Car has not overheated, no visable coolant in oil, no visable oil in coolant.

Is the headgasket bad, or am I just paniking for nothing.?

Thanks for your help.

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1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D

It should not bubble, unless it's pulling in air, but on a pressurized system, that is highly unlikely.

It bears watching, as it could be a bad gasket (likely), or a crack in the head or block (pretty rare on the OM617).

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Anyone else have any thoughts about this?

Engine runs great, starts fine, no unusal smoke, no oil in water or water in oil. (visible that is)

Are there some simple tests I could do to check if it is a headgasket? What is the pinch test some people have mentioned?

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1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D

The pinch test is done with the engine cold. It's a way to see if exhaust or combustion gasses are entering the cooling system. You squeeze the upper radiator hose. If it squeezes easily, usually no problem. If it holds pressure, then there is a problem. Either gasket or crack in the head or block.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

do an oil analysis high sodium levels will tell you coolant evaporating in the oil and ignore the naysayers about oil analysis stats

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commercial fisherman diesel in my blood in my boats trucks and Dear old Dad has had me drivin them since i got my first license in 1968
1986 300 SDL 427654
1999 Chevy Crew Cab Dually 225423
1986 300 SDL 287000 Dad's
1987 190 Turbo 158000 Mom's (my inheritance)