Been having problems with the main oil tank overfilling on our 2003 HPDI. It started about a month ago. Engine started smoking, because of overflow in airbox, and stalled. We replaced the main tank oil sensor. Engine worked good for a couple trips but then we started to get the same problem again. Never got any low oil alarms or problems from reserve oil tank sensor. Made sure assembly was installed correctly but the problem would continue intermittently.
Found this forum and did a search on "precison blend" as rodbolt suggested to better understand the system.
I am not a Tech by any means . . . but I have some basic skills and can perform some tasks . . . so please bear in mind.
We ran this weekend. We replaced the main sensor screen (just because it had not been changed in awhile). The engine ran flawlessly for the whole day, until we were coming back to port. Started smoking excessively and, as predicted, oil tank was overfilling. Disconnected the reserve tank harness to stop pump and limped the last 3/4 mile back to port (making sure to check level in oil tank so it did not run dry).
Back at the dock, I removed the reserve oil tank and checked for faulty or corroded connections/wires. Everything looked great. This morning I took a cruise around the bay. The system worked perfectly at WOT, trolling and idle speeds . . . drove for about an hour and no problems what so ever. I came back and disconnected the main tank sensor and checked for continutity for SW1, 2 and 3 . . . all there. I checked harnesss side continuity and everything was good. I jumped the harness side blue/green and blue/white . . . pump on, pump off fine. Here is were it gets crazy. I reconnected the sensor, drained tank till pump turned on, it started to fill however the pump would not turn off after fill line and overfilled the tank. Keyed off, keyed on. Disconnected the sensor and tested for continuity . . . good. Jumped harness again and I got the "on" but would not shut off and kept pumping till it overfilled. Keyed off, keyed on and the pump still ran. Keyed off and on again and again it kept pumping. Turned off batteries and disconnected both main and reserve tank sensors. Reconnected everything and turned batteries back on, pump now stopped. Drained tank till pump should have started . . . but now the pump would NOT turn on through sensor, tried to jump blue/green on the harness side but would not turn pump on??? Manual switch would run pump. Disconnected reserve tank sensor and tested continuity . . . was there. Reconnected sensor . . . now NO pump and NO manual switch??? Checked main sensor and harness again but still had reading. Turned batteries off then on and manual switch came back online. I used the manual switch to fill tank halfway between lines. Made sure everything was connected and put the cover back on the motor. Made a quick 1/8 of a mile trip at 4000 RPM to remove excess oil from airbox and cylinders. Ran great after everything was blown out. Got back to dock, took cover off of motor and oil level was filled to top line . . . where it is should be??????
The problem seems to be very intermitent. Most of the symptoms up till this point were the same but the all the problems from today were very unexpected. At this point I am thoroughly confused and out of ideas. I ran through almost every possible problem with the oil system in about an hour or so....I am totally perplexed by how the system was operating. I would assume that it is either a loose ground in the system or the ECU wiring harness....or, gulp, it is the ECU itself.
Any input would be appreciated. I don't know if anyone has any ideas or other tests I could possibly do? I would like to try to avoid taking it to a dealer or mechanic if possible. If it is the ECU, is that something I could change without taking it to a shop? It looks easy enough to get to, I just don't know if there are any resets, computer diagnostics or anything else I need to be aware of?
Sorry for the long post guys, thanks!!
Found this forum and did a search on "precison blend" as rodbolt suggested to better understand the system.
I am not a Tech by any means . . . but I have some basic skills and can perform some tasks . . . so please bear in mind.
We ran this weekend. We replaced the main sensor screen (just because it had not been changed in awhile). The engine ran flawlessly for the whole day, until we were coming back to port. Started smoking excessively and, as predicted, oil tank was overfilling. Disconnected the reserve tank harness to stop pump and limped the last 3/4 mile back to port (making sure to check level in oil tank so it did not run dry).
Back at the dock, I removed the reserve oil tank and checked for faulty or corroded connections/wires. Everything looked great. This morning I took a cruise around the bay. The system worked perfectly at WOT, trolling and idle speeds . . . drove for about an hour and no problems what so ever. I came back and disconnected the main tank sensor and checked for continutity for SW1, 2 and 3 . . . all there. I checked harnesss side continuity and everything was good. I jumped the harness side blue/green and blue/white . . . pump on, pump off fine. Here is were it gets crazy. I reconnected the sensor, drained tank till pump turned on, it started to fill however the pump would not turn off after fill line and overfilled the tank. Keyed off, keyed on. Disconnected the sensor and tested for continuity . . . good. Jumped harness again and I got the "on" but would not shut off and kept pumping till it overfilled. Keyed off, keyed on and the pump still ran. Keyed off and on again and again it kept pumping. Turned off batteries and disconnected both main and reserve tank sensors. Reconnected everything and turned batteries back on, pump now stopped. Drained tank till pump should have started . . . but now the pump would NOT turn on through sensor, tried to jump blue/green on the harness side but would not turn pump on??? Manual switch would run pump. Disconnected reserve tank sensor and tested continuity . . . was there. Reconnected sensor . . . now NO pump and NO manual switch??? Checked main sensor and harness again but still had reading. Turned batteries off then on and manual switch came back online. I used the manual switch to fill tank halfway between lines. Made sure everything was connected and put the cover back on the motor. Made a quick 1/8 of a mile trip at 4000 RPM to remove excess oil from airbox and cylinders. Ran great after everything was blown out. Got back to dock, took cover off of motor and oil level was filled to top line . . . where it is should be??????
The problem seems to be very intermitent. Most of the symptoms up till this point were the same but the all the problems from today were very unexpected. At this point I am thoroughly confused and out of ideas. I ran through almost every possible problem with the oil system in about an hour or so....I am totally perplexed by how the system was operating. I would assume that it is either a loose ground in the system or the ECU wiring harness....or, gulp, it is the ECU itself.
Any input would be appreciated. I don't know if anyone has any ideas or other tests I could possibly do? I would like to try to avoid taking it to a dealer or mechanic if possible. If it is the ECU, is that something I could change without taking it to a shop? It looks easy enough to get to, I just don't know if there are any resets, computer diagnostics or anything else I need to be aware of?
Sorry for the long post guys, thanks!!