dongfeng tractor with y385t wont start help

[Rich Waugh]

Yep, that's where the pressures run on my 304 Jinma with the TY395 engine.

 

[reelnative]

I wouldn't be so quick to conclude there's an engine oil bypass on that machine. I seem to recall discussions that recommended making sure that any replacement filter purchased has its own internal bypass, since the OE filter housing does not. Or perhaps just some OE filter housings did not, I don't recall the specifics anymore. That said, the drop to 50 psi @ 2000 rpm does suggest a relief valve somewhere.

That said, your pressure figures seem a bit high compared to the 4 Chinese tractors I've owned. Cold pressure among them averaged perhaps 50 psi, hot idle between 7 and 10, working temp at PTO speed around 35-40. When working them hard on a hot summer day it was not out of the ordinary to see 25-30.

Does your filter housing have a pressure adjust feature? It might look like a screwdriver adjust locked down by a hex nut. If so, you could lower the pressure so that it hits 50 max.

//greg//

mine isnt much off from that at cold start its 60psi warm at 1000rpms, at 80c amd 1000 rpms its 40 and at 2200 its 50psi and warm 80c at 800rpms its at about 35, i hate to say it but if your running 7 to 10psi at ldle warm that sucks no matter what kind of eng it is, anything below 20 is bad in any eng at any rpm, dont you get scared when you see your oil gauge almost pegging zero,, hahahha mine just goes from 40psi up to 65psi then back down to 50 on the way from 1000rpm to 2200 rpm

 

[Rich Waugh]

Mine runs around 9-10 psig at idle when up to full operating temp and I understand this is pretty normal for these engines and not something to be concerned about. As long as the oil is circulating through all the places it should, I can't see how it matters if it is doing it at 10 psig or 30 psig - the engine is getting lubricated. After all, many engines get along just fine with only "splash" lubrication and no oil pump at all. Some of these are industrial diesel engines too, not just lawnmower engines.

I'd be much more concerned about excessively high oil pressure, which could indicate a restricted flow in a critical area.

 

[reelnative]

Mine runs around 9-10 psig at idle when up to full operating temp and I understand this is pretty normal for these engines and not something to be concerned about. As long as the oil is circulating through all the places it should, I can't see how it matters if it is doing it at 10 psig or 30 psig - the engine is getting lubricated. After all, many engines get along just fine with only "splash" lubrication and no oil pump at all. Some of these are industrial diesel engines too, not just lawnmower engines.






I'd be much more concerned about excessively high oil pressure, which could indicate a restricted flow in a critical area.

yea it might be ok for these engs but that doesnt mean i have to like it hahaha, i would feel a whole lot better if an eng holds atleast 20psi when warmed up, I was worried when i thought mine was hitting 80psi but nowing now that 60 to 65 is were its topping out at, that doesnt bother me much, exp that the rings and bearings are all new, im sure it will drop when the eng gets broke in

 

[SPIKER]

Mine had a good gauge (China one) but I had 4 tractors (20' container full self import) and one of the others that I sold had a bad gauge so I swapped my China Gauge into that 284. I put a mechanical on mine that first week in May 2002 and it's oil pressure with the china shipping goo was 80PSI at start up 1000 rpm and stayed there till warmed up and drops back into the mid 60's on good oil. now after almost 600 hrs and well used up oil cold it sets at 1000rpm its 80 PSI cold and 50psi warm with idle and HOT it drops back in the teens.

Mark

 

[greg_g]

t if your running 7 to 10psi at ldle warm that sucks no matter what kind of eng it is, anything below 20 is bad in any eng at any rpm, dont you get scared when you see your oil gauge almost pegging zero,,

Nope. I was assured by a Chinese tractor dealer that I know and trust that there are no oil pressure concerns until hot idle is consistently below 6 psi. Owning/operating/maintaining four Chinese tractors over 10 years seems to have proved that 7-10 is indeed normal and safe. If in fact that your drop from 65 to 50 is being produced by a relief valve, the tractor is trying to tell you that the oil pressure is too high - a measure that protects gaskets and seals. Again, I point you toward the pressure/flow adjustment on the oil filter housing.

FWIW, my $36,000 John Deere 3720 doesn't even have an oil pressure gauge.

//greg//

 

[reelnative]

hi greg I looked
at my filter and on the side of the filter mount there is a larger bolt and a cap nut on top of it, is that the adjustment, the po might of messed with it before I got the tractor, but on the post above yours SPIKER says that his tractor runs up to 80psi on start up, and QUICKSANDFARMER has a eng that runs at 100psi on start up, could i have a very touchy valve that wants to dump early, if that bolt is the adjustment i will mark were it is now and adjust it to see what it does, but to me even 65psi is not a lot, with new bearings, pistons and rings the motor should have a higher pressure, to me it seems like my pump is cavatating at higher rpms and that is why it is dropping, I also will ck my oil level today, thanks everyone for the help,

 

[Rich Waugh]

Have you looked at the manual for that engine to determine if it has an oil pressure relief valve on the oil pump? Nearly every engine I've ever worked on had a ball check relief valve either on the oil pump or on the primary oil gallery.

 

[Bob Rooks]

...with new bearings, pistons and rings the motor should have a higher pressure, to me it seems like my pump is cavatating at higher rpms and that is why it is dropping.

There is no correlation between pistons and rings and oil pressure. I doubt your oil pump is cavitating.

 

[Rich Waugh]

I doubt a cavitating oil pump, too. I believe these tractors use a gear pump for the oil and they're not know for having cavitation issues. I think you'd have to spin one p to near supersonic speeds before it experienced any cavitation.