Mahindra losing power

[RedDawg]

Have a 2012 (no emissions) Mahindra 5010 gear drive tractor with @685 hours on it. Changed the oil, oil filter, fuel filter and air filter about 20 hours ago. Recently, after the tractor has run for about an hour the tractor will generally run fine but I lose power. To climb a hill, I have to down shift which I didn’t have to do before, especially if I have anything on the 3 point hitch. Any load on the tractor like thick weeds while bush hogging or an incline while discing drags the RPM’s down considerably. Once that happens, I can start to smell more diesel but I don’t see any leaks around the engine. You have to move the selector from high PTO idle speed to low idle slowly or the engine will die. However, if it dies, it will start right back up again. If you do decrease RPM’s to low idle without killing it, it will surge and porpoise for a while before smoothing out. The tractor is not running warm, and it is not using additional fuel. There is no smoke coming from the engine. There are no unusual sounds – just a decrease in power after an hour or so.

I think I may change fuel filter and air filter again. I have a few acres to mow with the 8’ Woods mower that hasn’t been cut since May when I did it last so it’s fairly thick. It will be interesting to see if it is normal power for the first hour and then loses power and bogs down.

Any ideas on what’s happening? Open to ideas and suggestions.

 

[Rustyiron]

I think you're right about starting with a fuel issue.
Is there a provision for draining-checking for water (condensation) in the tank?

 

[RedDawg]

I think you're right about starting with a fuel issue.
Is there a provision for draining-checking for water (condensation) in the tank?

Not that I can find. I'm the 2nd owner. Had it for about 150 hours at this point and have the owner's manual. Went through it last night looking for that very thing and didn't find anything on it. It would seem to me that water in the fuel would show itself right after start up and not wait an hour. I have added some Seafoam however for that reason.

Going to talk to my local deal when I pick up a new set of filters.

 

[Molalla1]

Have you checked for blockage from the fuel tank to your fuel filter?

 

[RedDawg]

Have you checked for blockage from the fuel tank to your fuel filter?

Yes, it's fine.

 

[Harry in Ky]

Have you considered that your fuel tank is mounted down low. You're relying on a ten year old electric fuel pump to pull fuel from it then push it up into and through the filter. You don't see a possibility of a problem there? Fuel pumps are inexpensive and easy to find. If it were my project I would go there next and do a little investigating.

 

[Jerry/MT]

Have you considered that your fuel tank is mounted down low. You're relying on a ten year old electric fuel pump to pull fuel from it then push it up into and through the filter. You don't see a possibility of a problem there? Fuel pumps are inexpensive and easy to find. If it were my project I would go there next and do a little investigating.

Put a T in the line at the outlet to the lift pump and measure the fuel pressure there. It should be 4- 6 psig. If you can, measure it when you are under load like hogging or climbing a hill. If it's less than 4 psig, you should consider replacing the lift pump.

 

[Mike1955]

Have a 2012 (no emissions) Mahindra 5010 gear drive tractor with @685 hours on it. Changed the oil, oil filter, fuel filter and air filter about 20 hours ago. Recently, after the tractor has run for about an hour the tractor will generally run fine but I lose power. To climb a hill, I have to down shift which I didn’t have to do before, especially if I have anything on the 3 point hitch. Any load on the tractor like thick weeds while bush hogging or an incline while discing drags the RPM’s down considerably. Once that happens, I can start to smell more diesel but I don’t see any leaks around the engine. You have to move the selector from high PTO idle speed to low idle slowly or the engine will die. However, if it dies, it will start right back up again. If you do decrease RPM’s to low idle without killing it, it will surge and porpoise for a while before smoothing out. The tractor is not running warm, and it is not using additional fuel. There is no smoke coming from the engine. There are no unusual sounds – just a decrease in power after an hour or so.

I think I may change fuel filter and air filter again. I have a few acres to mow with the 8’ Woods mower that hasn’t been cut since May when I did it last so it’s fairly thick. It will be interesting to see if it is normal power for the first hour and then loses power and bogs down.

Any ideas on what’s happening? Open to ideas and suggestions.

Where I would start, since you changed the fuel filters is to simply check and re do all that. Then make sure no air is in there. Since you worked there, it where you will find your problem. No offense mean sir, it just my opinion

 

[Rustyiron]

It's his power loss at/after about an hours use. Strange.
Fuel cap venting?

 

[Mike1955]

It's his power loss at/after about an hours use. Strange.
Fuel cap venting?

Rusty iron bear in mind it was running perfectly until he serviced it. Fuel is what he work on. That what I’m betting is wrong. Sucking air probably

 

[kneedeep]

I had a 5500 that did the same thing.
I found a plugged up screen in the fuel line before the filters if I recall.
It was a screen, just don’t remember exact location but it was at the fuel pump/filter area.

 

[Texasmark]

Besides the fuel related comments of which I agree, have you added fuel recently? If so, did you purchase it from your usual supplier and could it have become contaminated prior to your usage?

 

[3gunr]

This time of year brush hogging plugs air filters up in a hurry , my buddys LS has to be cleaned every hr or two or it starts losing power.

 

[svendawg]

Yes, it's fine.

I had the same issue. Turned out to be the screen in the fuel tank. Had to remove the petcock at the bottom of the tank and clean the screen.

 

[RedDawg]

UPDATE: I appreciate everyone's input - even those people who didn't read what I wrote before responding with ideas I said I already did.

I found the issue. Realizing that I was getting air into the fuel filter bowl and it wasn't staying full, I assumed it was a weak low pressure fuel pump. I went through the process of pulling the tank, the filter housing and the fuel pump. I wanted to clean out all the lines and flush the tank while I was at it. I replaced the fuel pump with a $15.00 generic 12v pump with exactly the same specs as the manufacturer's pump. Got it from that jungle website. The name brand replacement pump (same pump used on Mahindra, Yanmar, Kubotas, Cub Cadet and others) was $235.00 if you could find one. I put it back together and the initial indications were good. But I still noticed the bowl wasn't getting full. When I reved it to PTO speeds it would eventually run out of fuel in the bowl.

I played around with it for a while and started to notice something. One time I didn't turn the Fuel Selector on the filter housing fully to the 'ON' position before starting the tractor. The tractor ran great. As soon as I moved it that last little bit to the 'ON' position, the fuel started dropping in the bowl. I moved it back off of the 'ON' position just a bit and it would start to fill up again. Here is a video of that behavior. Selector Behavior

Now I understood. It was pulling air when the switch was in the full 'ON' position. The gasket behind the 'OFF, ON, AIR' selector was bad. You can see in the image below that the rubber is broken thereby allowing air to be pulled when it isn't supposed to be.

So, I call my Mahindra dealer. They don't even have an exploded view of the filter housing or that 'OFF, ON, AIR' selector. All they can sell me is an entire new filter housing for @$85.00. I haven't been able to find it online. Anyone know what this part number is? It's on a 2012 Mahindra 5010 Gear tractor. Any help tracking one of these down would be most appreciated. Appreciate everyone's help. Those of you suspecting "sucking air" - right on!

 

[kneedeep]

When servicing the 3510 several years ago,
I stripped the threads on the bowl nut trying to stop it from leaking fuel.
Part was backordered so I put a inline filter in its place temporarily.
Couple of years later, dealer found it in a box of odd parts not picked up.
He apoligized and gave it to me, no charge.
I put it in a tub marked SERVICE to put on next oil change.
Couple years after that, I realized I had the part down in the bottom of the box.
So when servicing the tractors this year, I finally put the new filter on.

BTW
I did change the inline filter every other oil change for the last 11 years.