View Full Version : 4JHTE using oil very fast but otherwise running OK

07-11-2008, 03:14 AM
"Not a question, but a tale of my experience. It'll happen to someone else one day! My only question might be "Did the fuel additive I used do this?"
I am fairly new to boating, and diesel engines. At the boat show, I was sold a fuel additive that (of course) was magic. I added this at the dosage prescribed to my diesel tank, at the first opportunity.
I take the boat out once a week. My first warning was the oil alarm on start-up, some weeks after adding the "magic formula". The dip-stick had read normal, but I hadn't removed the oil-filler caps when dipping. Upon re-dipping some time later, the stick showed as dry, so I filled the oil reservoir, and all seemed "fine". But where had the oil gone? It was not in the bilge. It looked to me as though the old oil had somehow gone into the fuel tank. The fuel HAD changed color (remember, I am no diesel mechanic), but everything was running as normal, so we went sailing. The engine is run for about an hour to get to where we'd typically cut the engine and sail. More oil was needed before start-up to return to "home". Otherwise, the engine seemed to run fine, with (maybe) a little extra smoke. I spoke to a few diesel mechanics, asking whether my idea that the oil somehow got into the fuel tank was at all possible. None gave it a moments notice. The more I used the boat, the harder it was to start. I got a (car) mechanic (neighbour) on to check things out. He though maybe the turbo was leaking the oil into the combustion chambers. He made phone calls, and got supportive comments. I then got a marine mechanic onboard, who listened to my reporting, ran the engine, looked at the smoke, listened to the sound, and finally diagnosed "death" - the bad news; but not the way engine usually die. Finally, I convinced him to look at the fuel. He immediately changed his diagnosis. Too much oil in the fuel tank! A phone call to a more-expert expert, and YES, there was a seal in the fuel lift pump that could lead to MY problem. Dumped fuel, a new pump, and all is well again. Thank goodness that I had NOT just changed the engine oil before my problems, or I might not have noticed the changed color of the fuel!
Happy boating all. Jez.}"