207WF Posted May 17, 2011 Report Share Posted May 17, 2011 Next oil change my fifth oil pressure sender goes in, at 560 hours, or about 100 hours of life on each. There are two kinds, the VDO for $45 or the other one with the metal band around it for more than $200. I am told the metal band does not improve the life much, but I never tried it. We have an LOA for a remote mount of the pressure sender to the firewall, the theory being that engine vibration is killing the units off, so they will last longer on the firewall. However, mounting them on the firewall requires adding two oil hoses that could leak. There aren't many oil lines on the rotax otherwise. Two more failure points (or four, if you count the connections). So, which is better? Should we replace these things at each annual or remote mount? Have those of you with remote mount had any failures? Any problems with the oil hoses? WF Link to comment Share on other sites More sharing options...
Roger Lee Posted May 17, 2011 Report Share Posted May 17, 2011 Hi Wayne, You only need one hose. It screws in where the sender comes out and goes back to the firewall and down just below the battery nest to your fuel pressure sender if yours is mounted there. I wouldn't bother with the Rotax VDO sender with the ring. The two VDO senders are identical except for that supposedly anti vibration ring, but you couldn't prove it by me. I have replaced several of the ringed VDO senders, but I haven't replaced one without the ring. The remote mount is absolutely the best way to go for you. It is an approved mod. Link to comment Share on other sites More sharing options...
Tad Olmsted Posted May 17, 2011 Report Share Posted May 17, 2011 Next oil change my fifth oil pressure sender goes in, at 560 hours, or about 100 hours of life on each. There are two kinds, the VDO for $45 or the other one with the metal band around it for more than $200. I am told the metal band does not improve the life much, but I never tried it. We have an LOA for a remote mount of the pressure sender to the firewall, the theory being that engine vibration is killing the units off, so they will last longer on the firewall. However, mounting them on the firewall requires adding two oil hoses that could leak. There aren't many oil lines on the rotax otherwise. Two more failure points (or four, if you count the connections). So, which is better? Should we replace these things at each annual or remote mount? Have those of you with remote mount had any failures? Any problems with the oil hoses? WF This mod is great, and there is one for the fuel pressure with the same set up. There is a kit that has one very important fitting that must be installed. The brass fitting that goes into the oil pump has a restrictor tapped into the middle of it. As we all know, the oil pump will evacuate all the oil in the system in less than a minute. Therefore if you ever have a hose failure on this mod, it will only piss out a very small amount so you will be able to make it back to base. Link to comment Share on other sites More sharing options...
airhound Posted May 17, 2011 Report Share Posted May 17, 2011 Is the oil sender failure rate peculiar to FD aircraft or common to all ROTAX powered acft? Where is it located? I don't think mine was replaced in it's 280 hours of history..What does VDO stand for? Link to comment Share on other sites More sharing options...
Jim Posted May 17, 2011 Report Share Posted May 17, 2011 Is everyone sure that your oil pressure sender is failing? I've had both crazy CHT readings and oil pressure readings. Replacing the slide-on crimp connector fixed the problem immediately in both cases. Changing a 10 cent crimp connector is way cheaper than a new sender. Link to comment Share on other sites More sharing options...
Roger Lee Posted May 18, 2011 Report Share Posted May 18, 2011 Oil senders do fail on Rotax engines. It is not specific to FD. Link to comment Share on other sites More sharing options...
Jim Posted May 18, 2011 Report Share Posted May 18, 2011 Roger, could you indulge me on this? Next time you see a sender problem, gently tighten the crimp on the connector where it hugs the sender terminal and retest. I think you'll find it fixes most of the sender problems. Of course, if it does, you'll want to replace the terminal as soon as it is convenient. Link to comment Share on other sites More sharing options...
Roger Lee Posted May 18, 2011 Report Share Posted May 18, 2011 Hi Jim, I do do that at every single inspection and every time some says they have an oil pressure issue. That is the first, quickest and easiest thing to do. I check the crimps and wires on all the temp senders. I just had a CT next to me with an oil temp swing of 20F or better. Pulled on the oil temp sending wire and it came right out. A new connector and problems solved. I never replace a sender unless I'm sure that is the problem. Link to comment Share on other sites More sharing options...
Jim Posted May 18, 2011 Report Share Posted May 18, 2011 Ok. I was just wondering because I've seen many posts about bad senders and none about bad connectors. Maybe I just missed them. Link to comment Share on other sites More sharing options...
airhound Posted May 18, 2011 Report Share Posted May 18, 2011 what does VDO mean and were is the oil pressure sender located on the engine generally? Link to comment Share on other sites More sharing options...
Jacques Posted May 18, 2011 Report Share Posted May 18, 2011 taken from the net '' 1928 - Merger with the Deuta-Werke to form VDO Tachometer AG – Vereinigte Deuta OTA, abbreviated to VDO; the brand name VDO is created in 1929 '' The oil pressure sender is at the oil pump..below the gearbox Link to comment Share on other sites More sharing options...
Tad Olmsted Posted May 18, 2011 Report Share Posted May 18, 2011 Is everyone sure that your oil pressure sender is failing? I've had both crazy CHT readings and oil pressure readings. Replacing the slide-on crimp connector fixed the problem immediately in both cases. Changing a 10 cent crimp connector is way cheaper than a new sender. Jim, good point! I am a firm believer of KISS We would automatically change the connectors on the CHT and oil temp when we first got a new CT from the shipping container. All the connectors used by FD are pretty cheap. Also, when changing the oil PSI sender in the pump, always install it dry. This is how it grounds. When you install the mod, you will have to get the sender with 2 poles on it. One for indication and the other for ground because it mounts to the composite firewall. Run a ground thru the fire wall and pick it up where all the others are (inside the mushroom, top starboard behind the EMS) Link to comment Share on other sites More sharing options...
airhound Posted May 18, 2011 Report Share Posted May 18, 2011 taken from the net '' 1928 - Merger with the Deuta-Werke to form VDO Tachometer AG – Vereinigte Deuta OTA, abbreviated to VDO; the brand name VDO is created in 1929 '' The oil pressure sender is at the oil pump..below the gearbox I've seen VDO here and there over the years. A Brand name. Thank you Jacques. Link to comment Share on other sites More sharing options...
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