engine oil pressure loss

Forum Forums Tractor/Dozer Engines engine oil pressure loss

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    • #34861
      Bob Rooks
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        The first thing I would do is check the gauge against a known quantity. In other words, a gauge that is known to be reliable and properly calibrated.

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      • #34863
        RichWaugh
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          I agree with Bob – the smallest orifice in the lubrication system is usually the one in the pressure sender itself and they do get clogged.  So I'd start by checking the sender and gauge first.  A side note is that they are also probably the cheapest components to replace if needed.

        • #34864
          Bob Rooks
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            As Rich said. I should have been more specific – a mechanical gauge.

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          • #34865
            DavidPrivett
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              I assume that the gauge you are looking at is electric powered.I would find a place on the engine that a mechanical gauge can be placed. You might have to add a t fitting. they do not lie. 

            • #34867
              Bob Rooks
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                Just remove the sending unit and install a mechanical gauge in its place.

                You will need a male metric to female NPT adapter (unless you can find a metric threaded gauge).

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              • #34870
                PrairieDog
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                  Guess I should have said it at the outset…. that was the first thing I did and the results were identical.

                  Mike

                • #34871
                  DavidPrivett
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                    I assume that the oil seems normal ,no diesel in it.I think you need to drop the oil pan look for maybe a loose oil pump? Or a part or trash causing a restriction to the suction pick up? Good Luck

                  • #34872
                    Bob Rooks
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                      At this point, before you do anything else, I would invest $25.00 and send in a lube oil sample for analysis. It will tell you if the oil is diluted with fuel (you can't always trust your nose), what type of metals are in it, how much soot and sludge are present, and if there is any coolant leaking to it. It will also tell you if the additive package has failed (foaming and aeration of the oil). Or, you can change the oil & filter and see if that helps. My speculation says it won't.

                      I have to ask what type and brand of oil are you using, and what is the ambient temperature when you are working the tractor?

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                    • #34876
                      PrairieDog
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                        Thanks, Guys.  I had not thought of an oil analysis, any I have found here have been a lot more than $25… usually over a hundred.  Maybe I just haven't looked hard enough.  The oil seems very normal.

                        Also never thought of foaming.  It was very hot both days, and I expect it was being operated at full rpm, (I wasn't in the seat).  The oil is Canadian Tire, so its quality is suspect… up there with Walmart house brand.  But it is the same oil I have used for over 5 years without a problem, although I do not work my engine at high rpm for long in high temperature conditions.  I did add oil to about half a litre over the full mark, and the problem has not repeated, but then again the weather has cooled down. 

                        I think I'll change the oil to a better quality of oil, and see how it goes.    I'll save a sample, and do the poor man's analysis (cut the filter in half).  But, like you, I doubt it will fix it.  It will, however, rule out that possibility.  If that doesn't work, then off with the pan, as David suggests.

                        It sure is bothersome to not know!

                        Mike

                      • #34877
                        Bob Rooks
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                          Try here. $25.00.

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                        • #34878
                          PrairieDog
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                            Thank you, Bob.  I will.

                            Mike

                          • #34879
                            Bob Rooks
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                              You will probably find, as I have, that you can extend oil change intervals. I currently have over 250 hours on my engine oil and it's fine.

                              I'm using Delo 400 15w-40. Shell Rotella-T is another good brand for example.

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                            • #34880
                              DavidPrivett
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                                you know I as thinking maybe it could be something with the oil filter housing if it has a oil pressure adjuster that has gone wierd on you. I can not think of why but stranger things have happened.I am still thinking.

                              • #34881
                                Bob Rooks
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                                  That’s entirely possible. There could be an internal crack in the casting and it wouldn’t leak or open up until it was hot enough. These engines don’t have oil coolers like the higher end machines do so they have the oil heat indirectly carried away by the cooling system (the oil can run 10 -20 degrees hotter than the coolant), which is another thing to check. Make sure the radiator fins are impeccably clean when running under high r/m loads when the ambient temperature is high, also make sure the engine coolant passages are clear. A good chemical flush and rinse will take care of that, and the use of a high quality coolant such as Final Charge or equivalent, will make a big difference

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                                • #34882
                                  PrairieDog
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                                    Thanks guys… good suggestions.  Since I was not the operator, I have no idea what the coolant temp was at the time, but it was a hot day and he was haying.  I know the rad was clean in the spring, and the coolant was new and up to level, but it sure bears checking.  Currently I'm waiting for the oil analysis kit to arrive and there has not been a recurrence. 

                                    I had disassembled the oil filter relief valve to make sure it wasn't stuck, but never thought of a housing crack etc.   As you said, David, “stranger things have happened”. 

                                    Mike

                                  • #34883
                                    DavidPrivett
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                                      Does the oil pressure reduce slowly as it gets hot or does it go away all at once? And by chance did you restart it after a few moments and the oil pressure came up? I am wondering if it is maybe a restricted oil return hole under the valve cover,maybe the oil is mostly staying up there and starving the sump.But I think that might be unlikely but need to check out.

                                    • #35015
                                      hapkido41
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                                        Did you get a resolution to your oil pressure problem?

                                      • #35017
                                        hapkido41
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                                          The reason I ask is I am having the same problem. Thanks Doug.

                                        • #35033
                                          PrairieDog
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                                            Sorry guys, life apparently got in the way of posting an update.  First grandchild is due any day now… I don't recall this much activity when we had our own.

                                            As for the tractor:

                                            All I have done is to change oil to Shell Rotella, new filter, and I'm told it now runs just fine, but the pressure is on the low side.  I have taken a sample, and expect to get the results soon.

                                            I have come to the conclusion that David is right… the problem is likely somewhere in the oil filter housing.  The pressure changes are reported to be abrupt rather than gradual.  Relief valve malfunction? Economy oil foaming in exceptionally hot weather?  Still a mystery.

                                            Since it seems to be working OK, and we are nearing the end of the season I think I will wait and do any further work in my shop instead of on my back in the dirt.  That will also give me an opportunity to drop the pan and inspect a bearing or two.

                                            mike

                                          • #35035
                                            hapkido41
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                                              Congratulations on your first grandbaby!!! Thanks for the reply/Help, Doug

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