wmonroe
Elite Member
Got it, thanks
HST Plus DS Hi/Lo hiccup
- Thread starter rScotty
- Start date
Got it, thanks
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rScotty
Super Member
- Joined
- Apr 21, 2001
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- 8,258
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- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
A bit more info.... Kubota'a version of an EGR valve is nothing at all like the simple old EGR "clatter valves" used on automotive gas engine intake manifolds for a couple of decades in the late 60s to 80s.
The Kubota version is pretty complex & was only used for a few years. I don't know if Kubota's EGR engines had anything to do with emissions regulations, but adding an EGR to their popular & proven old direct injection 03-M series engines just happened to fit a loophole called the "Interim" Tier 4 Emission Regulations.
That loophole allowed Kubota to continue with their old proven 03-M direct mechanical injection engine in some tractors from 2007 to 2012 . The EGR version was discontinued when the interim regs expired and soot (black smoke) reduction became more strict.
Those EGR motors appear to be good reliable engines. Maybe they are a bit of a fuel hog like any diesel that "rolls coal" when loaded down.... As near as I can tell by turning the EGR on our M59 on and off, it's not the EGR that makes them smoke. I'm not 100% sure, but suspect they smoke because of retarded injector timing to produce less NOx emissions - which also fits the Interim Tier 4 regs.
rScotty
OP
rScotty
Super Member
- Joined
- Apr 21, 2001
- Messages
- 8,258
- Location
- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
Well, that's interesting. How did you know? I am probably due for a full hydraulic fluid and filter change. It has about 400 to 500 hours on the last one. I don't use the fluid hard and rarely use over half throttle unless I'm roading it. The fluid is perfectly clear and tests well on blotter paper. I'm considering just swapping in a few quarts of new SUDT to offset any additive depletion and perhaps changing the filter.
Up until that single isolated instance I had never noticed any Hi/Lo hunting in 1st, 2nd, or 3rd range. But then I don't use HST+ Autoshift, just the manual trigger on the steering column. It's always been instantaneous until the hiccup.
rScotty
5030
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- Kubota M9000 HDCC3 M9000 HDC
One never knows do they? I probably should have said, not continuous black smoke, only time mine blow off visible particulates (smoke) is when throttling up or assuming a load (like spooling up my disc bine). When running, they just give off heat from the stacks, no visible smoke at all.
Continuous black smoke is an indicator of over fueling or a clogged air filter or some other issue that needs addressed.
If course the post 4 units 'digest' that smoke in the SCR units or the DEF units in the case of larger displacement units which at some point need cleaned or renewed. The smoke is still there, you just don't see it...
5030
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- SE Michigan in the middle of nowhere
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- Kubota M9000 HDCC3 M9000 HDC
Interesting comment. According to my shop manuals, both of my M9's are 'Interem Tier 4' engines but neither have any sort of EGR on them. The only device they have on them is the wastegate or what I refer to as the 'puff limiter' which is similar to what Mack used on their diesel engines to mitigate the 'puff of black smoke when throttling up the engines. The ones I have are a spring loaded affair that I've never fooled with. No need to. Well depicted in the workshop manuals. Both of mine are the 3 valve engines as well.
wmonroe
Elite Member
I agree the retarded valve timing causes some smoke and also greatly contributes to the smokey cold starts. The same engine prior to interim tier 4 had the timing advanced quite a bit more. It’s on my to do list to adjust but haven’t found the time yet.