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x758 Oil Pressure Light

11K views 19 replies 8 participants last post by  SulleyBear 
#1 · (Edited)
I'm new to the forum and would appreciate some help. I have a 2013 x758 with 229 hours on it and a brand new 60 HC deck. I bought it used and mowed with it for the first time last night. I noticed that the Oil Pressure warning light would come on occasionally and then go off. I seemed to notice it most when on an incline or bouncing around in a rough area. It may stay on for a second and go off or several seconds and go off. It never stayed on. There was zero decline in engine performance however. It runs great.

I have driven it around quite a bit over the last week and this has only happened when running the mower. The oil really looks fine, but it is filled a little above the marks on the stick. Could being a little too full affect this? I have JD oil and a filter to do a change if needed.

I'm also wondering if the oil pressure sender switch could be bad. I did read somewhere online about Yanmars being notorious for this sensor going bad. Where is this located on the engine? And is this something I could replace myself without any special tools?

Thank you in advance for any input or advice.
 
#4 · (Edited)
At this point it could be anything. It is the switch, wiring, pump, or filter. When was the last time you change the oil filter? I am thinking that it should have a bypass valve though. All will need to be investigated and ruled out. I personally would start with the wiring and then the switch. I don't think over fill would yield any pressure issues.
 
#5 ·
I would start at the pressure switch. You may have a lose wire terminal. Start there first. If the wire is grounding someplace, that will cause the same problem. Like if the wire wore through the insulation somewhere. The oil pressure switch works by going to ground when there is no pressure. With the engine running, you should be able to take the wire off the switch, ground the wire, will not hurt anything, and the light should stay on as long as you have it grounded. A bad switch will do the same. I would go with the wire first. Should you not find anything on the wire side, I would find someone that has an oil pressure gauge, check the actual engine oil pressure. This eliminates the oil pressure problem. Then most likely it is a switch. Or, eliminate the switch and install an oil pressure gauge and get rid of the "Idiot Light".
 
#6 ·
This may be a silly question, but if it were something wrong with the engine internally I would notice a change in power or performance when the light comes on right? The fact that the engine sounds and performs the same is what is making me think that is is the switch/wire/light. I would think if the oil pressure actually is dropping that the engine performance would change.
 
#7 ·
Ok, so I checked the wiring first as you both suggested and I believe it is ok. I disconnected the wire from the sender switch while running and grounded it. If I kept it grounded, the light would stay on. So I replaced the sender switch. It was a $20 part, so worth a shot.

I mowed last night and for the first 30 minutes or so all was good. But then after that, the oil pressure light started to come on and off again.

So I changed the oil and filter last night and we will see if that makes a difference.
 
#10 ·
Sounds like you need to get a oil pressure gauge and actually see what is going on inside the engine. That would solve this problem.
 
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#9 ·
There is no warranty remaining on this one. How I acquired this machine was from a JD Dealer across the street from one of the JD forestry division plants. JD uses x700s in their factories for pulling around tool carts, tour carts, etc and then they send them to a local dealer to prepare for auction. Some the dealer keeps. But JD does not warranty any of the equipment they have used internally and then sell. It was never in the dirt or had anything hooked to it except carts. Since it was the tractor only, I had the dealer add a brand new 60HC deck and I purchased it all in for about $1200-$1500 less than comparable units cost that were privately owned, but still have about 1 season of warranty.

It had 227 hours on it, so I took a chance figuring on the durability of the yanmar diesel and everything else about the x700s. Plus I figured $1200-$1500 could go a long way toward repairs if something did go wrong. I just hope it doesn't come back and bite me in the butt!
 
#12 ·
I plan on mowing again this weekend or monday and we will see what happens, since I changed the oil and filter. The old oil and filter didn't look very good.

After that, if it's still happening I will find a gauge and test it. Does anyone know the operating range for the Yanmar 3tnm74 at full throttle? I think I saw someplace that it was 41-51 PSI.

If the oil pressure is dropping according to gauge, then what is the next step? The Oil Pump? If that's the case I would have to have local dealer do it. Anyone know how much it costs to have a pump replaced?
 
#13 ·
I would check the pressure before you use it. If you lock it up the bill will get way more expensive.
 
#14 ·
I am happy to report that since changing the oil and filter the warning light has not been coming on. Mowed yesterday and never came on. However I was so focused on the oil pressure light that I completely ignored the fuel gauge! Yes, I ran out of gas. All I was paying attention to was the grass in front of me and the warning light on the dash. Bonehead move, but at least I learned that the fuel gauge is accurate.

Since I bought it used, I don’t know when the last oil change was, but apparently too long ago. So in order, I checked the wire from the sender switch to the dash. I replaced the sender switch. Then I changed the oil and filter.

Thanks for all of your help and suggestions.
 
#15 ·
I am happy to report that since changing the oil and filter the warning light has not been coming on. Mowed yesterday and never came on. However I was so focused on the oil pressure light that I completely ignored the fuel gauge! Yes, I ran out of gas. All I was paying attention to was the grass in front of me and the warning light on the dash. Bonehead move, but at least I learned that the fuel gauge is accurate.

Since I bought it used, I don’t know when the last oil change was, but apparently too long ago. So in order, I checked the wire from the sender switch to the dash. I replaced the sender switch. Then I changed the oil and filter.

Thanks for all of your help and suggestions.
This is exactly why I do a full service on all used equipment the very first thing (no matter what the owner claims). And it is wise to look over new equipment prior to major use. :thumbup1gif:
 
#16 ·
At least it was an easy fix. I think I would go over everything, to include the hydro system. Then you know what you have. Easier to fix than if it runs out of oil.
 
#18 · (Edited)
I've looked over the Hydro and it's got good oil and no leaks that I could find. It was a little low when I first got it, so I added some hy-guard. The oil in there appears super clean though. There are no leaks anywhere that I could find with any system. The cooling system was good and the air filters were either brand new or had never seen a spec of dust.

The previous engine oil looked decent on the dip stick, but when I drained it, it looked pretty bad compared to the new.

Now that everything seems to be good, all fluids good and everything greased, I can get on a regular maintenance schedule. I plan on just having the local dealer do a once yearly service of everything each spring. I look forward to a lot of years of used out of this set up.

If nothing else, I learned a few things about the machine and I joined this forum! I absolutely love using the tractor. It's a completely different experience than my previous L120! I was down to a z930m zero turn, possibly a scut or the x758. I researched for over a year before buying and I believe the 758 was the perfect fit for my needs.
 
#17 ·
Glad to hear it was a simple fix. Don't worry, I've ran out of fuel twice now. It always a process to get it going again. The key is to shut it off before it dies on its own. That much less air you have to bleed.
 
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#20 ·
I'm new to the forum and would appreciate some help. I have a 2013 x758 with 229 hours on it and a brand new 60 HC deck. I bought it used and mowed with it for the first time last night.
Welcome to the GTT forums and congratulations on your new tractor purchase......:bigthumb:


Since you are new to the diesel SCUT ownership, I would like to make a few suggestions. I own a 455, which is a predecessor to the X750 diesel. I have owned and enjoyed my tractor for about 20 years and my tractor has 2,600 plus hours on it.

The Yanmar is a great engine and ideal for these tractors. I wouldn't own a tractor of this size with a gas engine, but that is something people on both sides of the issue have strong feelings about.

I would suggest that you now start using a HIGH QUALITY Synthetic Diesel Engine Oil in your tractor. I use the Amsoil products in my tractor and my wife's Ford Expedition. I use Mobil One in my Mercedes Benz and Harley Davidson. Both the Amsoil and Mobil One are top quality products. Just make sure it is an oil designed for diesel engine use. Also, don't buy into the "extended change interval" nonsense. Oil is cheap compared to engine repairs or replacement.

AMSOIL Premium Protection 10W-40 Synthetic Motor Oil

I would suggest taking a permanent marker and writing on the underside of your hood the date and engine hours of the service you do to your tractor. That way it's right there to see and you have a whole log of what you have done in front of you. Plus it encourages one to keep their engine compartment clean.....Just write it big enough that you can read it.

I change the engine oil every 50 hours of use. Engine oil is cheap compared to a new Yanmar engine or it's major repairs.

I change the Hydrostatic Fluids every 100 hours. I use the John Deere Hydro fluid and buy it in February on each year during heir filer and fluids sale which gets another 15% to 25% off fluids and filters at John Deere. I buy the Hydro fluid in the 5 gallon pail as I change it two or three times a year. Plus the old pails are great for recycling the old oil and hydro fluid. Just mark them so you or someone else doesn't confuse the new and old containers.

Use only Deere or high quality filters. Some of the cheap filters on the market do not have pressure bypass valves in them and should the cheap filters plug, you are buying a new engine as it can starve the oil supply. Plus cheap filters can collapse internally. They are cheap for a reason.

Keep a fuel filter in your garage toolbox for your tractor and change it annually. Always keep a spare new clean fuel filter. Also, make sure to use only a dedicated Diesel Fuel jug and never allow it to be used for any other liquids or fuel. I am always amazed at the people who want to save a couple bucks and use an old gas can. Bad idea for lots of reasons.

I suggest using a fuel additive in all of your diesel fuel year around. I use the Howe's Fuel supplement. The good fuel supplements displace water, keep from gelling in the winter and add lubrication to the fuel which helps with the injector pump, etc.

Howes Lubricator

Keep your tractor clean and greased and pay attention to the air filters, as you mentioned in your comments. You are in the track to many, many years of enjoyable Deere tractor ownership......Enjoy your new Deere!
 
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