Bobcat 873 low oil pressure light comes on

[AaronsLawnService]

Hey guys. I have a 2001 bobcat 873 with the deutz engine. The other day the oil pressure light came on. So we pulled the sending unit off and replaced it. The light was still on so we checked the oil pressure, cold it was 40 but when warmed up was only 20. So I am thinking it's possibly the pressure relief valve? Does this sound right or could it be something else? Also I don't know where the relief valve is located on the bobcat. Also the light takes usually 3 or 4 minutes to come on once started. I don't know a lot about skid loaders so I figured I would ask you guys. Any help is greatly appreciated! Thanks Aaron

 

[mmsllc]

Sounds like a wiring problem. I would check every inch of your wiring harness for obvious signs of damage. I would scrutinize over areas near pinch point, hinges, hot exhaust manifolds, etc. If nothing jumps out at you, I would do the following: Turn the key on, verify the oil pressure light is on. Then, unplug the sending unit, is the light still on? If so, it sounds like the wire that runs from the oil pressure sending unit to the oil pressure light is grounded some how. You can run a wire to the light & to the sending unit. Does the light operate correctly now? If so, you can easily add that wire to your machine to restore the oil pressure light. I will say that it is the easy & cheap way of repair, but it could require a new harness otherwise to repair the preferred way. I have seen wiring issues repaired this way on quite a few these machines. The other obvious repair

 

[Clone]

Sounds like a wiring problem. I would check every inch of your wiring harness for obvious signs of damage. I would scrutinize over areas near pinch point, hinges, hot exhaust manifolds, etc. If nothing jumps out at you, I would do the following: Turn the key on, verify the oil pressure light is on. Then, unplug the sending unit, is the light still on? If so, it sounds like the wire that runs from the oil pressure sending unit to the oil pressure light is grounded some how. You can run a wire to the light & to the sending unit. Does the light operate correctly now? If so, you can easily add that wire to your machine to restore the oil pressure light. I will say that it is the easy & cheap way of repair, but it could require a new harness otherwise to repair the preferred way. I have seen wiring issues repaired this way on quite a few these machines. The other obvious repair

From what I found, 20.3 at 900 rpm is the minimum with hot oil per the Deutz manual. So the light appears be to doing its job. I would start with rebuilding or replacing the regulating valve first and see if that improves your oil pressure. How many hours on the machine?

 

[AaronsLawnService]

Sounds like a wiring problem. I would check every inch of your wiring harness for obvious signs of damage. I would scrutinize over areas near pinch point, hinges, hot exhaust manifolds, etc. If nothing jumps out at you, I would do the following: Turn the key on, verify the oil pressure light is on. Then, unplug the sending unit, is the light still on? If so, it sounds like the wire that runs from the oil pressure sending unit to the oil pressure light is grounded some how. You can run a wire to the light & to the sending unit. Does the light operate correctly now? If so, you can easily add that wire to your machine to restore the oil pressure light. I will say that it is the easy & cheap way of repair, but it could require a new harness otherwise to repair the preferred way. I have seen wiring issues repaired this way on quite a few these machines. The other obvious repair

Mmsllc Thanks for the fast reply. I will try the things out you recommended tomorrow and let you know how it goes. I did check the continuity of the two wires that go from the computer to the sending unit. The 3510 wire had continuity all the way. The other wire (3520) had continuity from the sending unit to the large wiring plug on the left side of the motor but it didn't have continuity all the way to the computer. I wasn't sure if the wire was suppose to have continuity all the way to the computer or not. Sorry I'm not very good with wiring.

 

[AaronsLawnService]

Mmsllc Thanks for the fast reply. I will try the things out you recommended tomorrow and let you know how it goes. I did check the continuity of the two wires that go from the computer to the sending unit. The 3510 wire had continuity all the way. The other wire (3520) had continuity from the sending unit to the large wiring plug on the left side of the motor but it didn't have continuity all the way to the computer. I wasn't sure if the wire was suppose to have continuity all the way to the computer or not. Sorry I'm not very good with wiring.

It has 2000 hours on it. Where is the regulating valve located? Thanks Aaron

 

[Clone]

It has 2000 hours on it. Where is the regulating valve located? Thanks Aaron

I don't know where these components are. This is the thread I was getting some info from. http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=50062 It appears there is a relief and a control valve and both probably have springs that could be getting weak? I'm sure some 873 deutz expert on here can guide you better.

 

[lesgawlik]

I don't know where these components are. This is the thread I was getting some info from. http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=50062 It appears there is a relief and a control valve and both probably have springs that could be getting weak? I'm sure some 873 deutz expert on here can guide you better.

Does your dipstick have plastic on it? The Deutz engines had problems with the plastic breaking into pieces and jamming the spring in the pressure relief valve. You may wish to remove it and check for foreign material. Mine had that problem. At start up, the oil was cold and pressure was okay. When the oil thinned out, the pressure would get to the low border of normal. Although the dipstick was replaced by a previous owner, a piece a plastic got into the relief valve and interfered with its operation.

 

[mmsllc]

Does your dipstick have plastic on it? The Deutz engines had problems with the plastic breaking into pieces and jamming the spring in the pressure relief valve. You may wish to remove it and check for foreign material. Mine had that problem. At start up, the oil was cold and pressure was okay. When the oil thinned out, the pressure would get to the low border of normal. Although the dipstick was replaced by a previous owner, a piece a plastic got into the relief valve and interfered with its operation.

You are most welcome, I think anyone who asks a question deserves an honest answer (even if it is based on opinion or experience). The regulating valve SHOULD be located behind the oil filter. It should look like a plastic disc that is held in place by a small / tiny snap ring. It COULD also be located in the actual oil pump of the engine as well. If that is the case, removing the engine is the BEST & CHEAPEST course of action over the long run. Of course at that time, you could inspect for the plastic debris pieces that another poster has mentioned. I would take out of service very soon, before it starts to come apart. It CAN get very EXPENSIVE very quickly if not.

 

[7LBSSMALLIE]

Does your dipstick have plastic on it? The Deutz engines had problems with the plastic breaking into pieces and jamming the spring in the pressure relief valve. You may wish to remove it and check for foreign material. Mine had that problem. At start up, the oil was cold and pressure was okay. When the oil thinned out, the pressure would get to the low border of normal. Although the dipstick was replaced by a previous owner, a piece a plastic got into the relief valve and interfered with its operation.

origanil dipstick had yellow plastic ribs. heat made them brittle. prone to break off. updated dipstick still yellow but smooth. located next to flywheel housing are four ports. two standoffs. 2 plugs dependining on heater equipped. take apart and clean don't mix em up. 1 is eng oil pressure regulator one is temp regulator. (basicily a stat for an oil cooled eng.) typically this is where low eng oil pressure.s issues are found. not the stat but the relief. the deutz was basically bullet proof. they don't like dirt or being babied. worth a mention is if lift pump fails. can either transfer fuel into oil or oil into fuel. fuel into oil will thin it creating low pressure as well.

 

[rodbuilder]

1. Buy a cheap oil pressure gauge at Oreillys or A-Zone and get a hose to adapt it to your oil sending unit port. (Take the sender along with you, so you can find the right thread) Test the oil pressure. 2. If it's good with a gauge on it, you have a wiring problem in the sending unit circuit, or a bad gauge on the loader. 3. If it's still bad using your "tester", you either have a bad oil pump or a SERIOUS problem in the engine - like severely worn cam, rod, or main bearings. All else is B.S!!!!

 

[rodbuilder]

It's inside the oil pump........which is inside the pan!!!! And you don't "fix" the regulator you buy a new oil pump. Only a complete tightwad would mess with "repairing" an oil pump that cost a measly $100. Screwing around with an oil pump is as ridiculous as "fixing" a fan belt!!! Your big problem will be removing the engine to get to it!!!!! But if you find that it's a bad sending unit wire, you could always run a new wire to the gauge, or just screw a new gauge into the sending unit port........if the gauge is really that important to you.

 

[7LBSSMALLIE]

It's inside the oil pump........which is inside the pan!!!! And you don't "fix" the regulator you buy a new oil pump. Only a complete tightwad would mess with "repairing" an oil pump that cost a measly $100. Screwing around with an oil pump is as ridiculous as "fixing" a fan belt!!! Your big problem will be removing the engine to get to it!!!!! But if you find that it's a bad sending unit wire, you could always run a new wire to the gauge, or just screw a new gauge into the sending unit port........if the gauge is really that important to you.

without readining the entire post. once again we are back to does it have a ribbed dipstick, and if so are ribs busted? 20 second check.