ian38_39
New member
A friend of mine has a bit of a problem a bit of a teaser with a 6 cylinder VM diesel engine (same as four cylinder used merc and BMW circa 96 separate cylinder heads)
Engine starts from cold and oil pressure rises straight to around 5 bar and drops to around 2bar at 750 rpm once the engine is up to temperature. Now if I stop the engine and restart after a couple of minutes all is fine and oil pressure comes straight back up but if I stop for 15minutes or more once I restart the oil pressure is zero and oil light on for around 2 minutes before going straight back up to 2 bar.
During this time there is no noise from the bearing at all.
I have tested the sender and gauge and then cracked open an oil feed banjo that feeds the rockers to confirm there is little or no oil pressure during this time. I changed the oil which had only done 1000 miles and this seamed to solve the problem on the first couple of test but still took 15 secs to record pressure on the third test. The oil is 15/40 mineral and the pump is cog driven behind the front cover.
Any one got any ideas what this could be. When the pressure comes up it stay at2 bar at tickover and rises to 5 bar when revved.
Thanks in advance
Engine starts from cold and oil pressure rises straight to around 5 bar and drops to around 2bar at 750 rpm once the engine is up to temperature. Now if I stop the engine and restart after a couple of minutes all is fine and oil pressure comes straight back up but if I stop for 15minutes or more once I restart the oil pressure is zero and oil light on for around 2 minutes before going straight back up to 2 bar.
During this time there is no noise from the bearing at all.
I have tested the sender and gauge and then cracked open an oil feed banjo that feeds the rockers to confirm there is little or no oil pressure during this time. I changed the oil which had only done 1000 miles and this seamed to solve the problem on the first couple of test but still took 15 secs to record pressure on the third test. The oil is 15/40 mineral and the pump is cog driven behind the front cover.
Any one got any ideas what this could be. When the pressure comes up it stay at2 bar at tickover and rises to 5 bar when revved.
Thanks in advance