Iseki TX1510 Oil Pressure

[Ernie-32]

And we're back, with again oilpressure light coming on after some towing even on horizontal level and only right after rpm drops from around 1800tpm normal work speed back to stationairy at say 800tpm. Once lit, accelerating has no further effect, pressure keeps being close to none. So that, together with the poor availability of spare oil pumps (appearently there's no market for it), made me realise something else could be wrong. One thing can be that oil is not returning to the oilsump quickly enough to keep level. So the oilpump is not to blame for low pressure but the supply of oil to the pump might be?
Not looking forward to opening up the carter, I bought a cannister of 300mL engine carter cleaner. A fluid that is mixed with the engine oil 20 minits right before an oil & filter change. It needs to run that long, only stationairy (not hard working!) and right after stopping the engine, take the plug out, remove the filter and drain oil thourougly.
Also switched from low-budget-horse-piss-SAE30 (prejudism) to a solid well paid for 10W40 oil, and for the moment all seems fine again! Did a very long job today for 3 hours in the fields and coming back into the garage, running stationairy as a sunshine without oil pressure light coming on. Wauw. It's been a while

While I was at it, also put 50mL dieselinjector cleanerfluid in the fueltank, hopefully I added a few more years of tractorfun by doing so.

Totally besides the subject; added a "steer pulley" or how is it called? Very handy to have:

Greetings from Southern France

 

[lens12]

My first thought on the oil light is the sending unit is bad. I've run across this often on tractors I imported from Japan.

 

[Ernie-32]

My first thought on the oil light is the sending unit is bad. I've run across this often on tractors I imported from Japan.

Thanks for reacting Leonard, you most likely did not read my post before the last one (#10) where I had already checked the real pressure against the light coming up with a pressure gauge, which indeed shows pressure falling away when hot and revs low :-(
Today this already happened after just 15min at work. I really need to take off the carter and check/clean the inlet filter of the oilpump that sits right there. Also check/clean oil channels that the pump uses to suck up the oil from the carter. The pump itself is so simple, can't go wrong you'd say!

 

[lens12]

I wouldn't be to concerned if it only comes on when hot & at idle as long as you weren't trying to work it at idle. If it had low pressure at high RPMs I'd be concerned.

 

[Ernie-32]

I hope this is my last update on the matter. AGAIN oil pressure light came on now even after 15min of only light work. Took down the front axel in order to remove carter. Inspected oil inlet filter (a spring lightly forced open acts like a filter!) and removed oilfilter and then finally the trochoid-type oil pump. Cleaned outsides thouroughly before taking out the pressure valve.
My theory was that if this valve opens above 7bar but does manage to shut again when pressure drops at low revs and a hot engine, the pressure fails totally.
Could not find anything really wrong so cleaned it and reassembled it with lots of clean oil. Then after blowing clear carefully the pump inlet channel with compressed air, I had no options left and assembled it all. To my big surprise it makes all the difference!!! The problem is gone.
Coming weeks I'll be driving around with an improvised manometer but this is only a precausion not to be emptyhanded if the problem reoccurs.

 

[Ernie-32]

3 weeks later, done a lot of work and I can now safely remove the manometer and rely again on my oil pressure switch. All seems to be okay! When really hot, pressure drops to just over 2 bar but switch triggers only below 1 bar, so we're gooooood

 

[Ernie-32]

*** UPDATE ***
After weeks monitoring oilpressure I was convinced it was always above 2 bar pressure, even on low revs and very very hot. I put back the original pressure switch and at first things looked okay, until I had some really challenging mowing to do and there the light came on again :-(
So now I finally ordered a new switch (ref. TP13109 at tractorpartz.com for 39€ home delivered) and continued my steep-climbing-while-mowing job and it did not light up.
==>> so in the end I can only draw the conclusion it has been a combined problem of over-pressure release valve not properly returning when hot, and a switch failing when hot. We learn as we go......