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tier 4 doosan engines in bobcat
- Thread starter warbird
- Start date
The local Bobcat salesman said that because they do not use a DPF that the Doosan engines must run at a higher exhaust temperature to burn off the particulate matter and the engine derates until the exhaust temps get hot enough. He said this has caused some of his customer's machines to run derated for up to an hour during snow events because the engines just don't see much engine load pushing snow. His customers hate the "cold" word that pops up on the screen and beeps at them.
durallymax
Senior Member
I've heard the same about issues in cold locally but don't know the machines well enough personally.
Mostly farmers with complaints, they jump in and run for a couple minutes and shut them down. All day.
Mostly farmers with complaints, they jump in and run for a couple minutes and shut them down. All day.
crewchief888
Senior Member
from what i've seen so far with the EFI engines that bobcat is using, the doosan in the mid frame machine has been more trouble free than the kubota that was used in the large frame machines. the kubota has DPF on it, and operators like to override the regen.
eventually leads to a plugged DPF, and 75% derate, neccesitateing a service regen.
biggest issues are in extreme cold weather running #2 fuel. all the EFI engines use a 2 micron fuel filter that doesnt "like" cold fuel.
using a 50/50 mix of #2 & #1 fuel helps the fuel flow through the filter.
bobcat has added a fuel warming curcuit to bypass the fuel cooler in cold weather on the doosan engines.
:drinkup
eventually leads to a plugged DPF, and 75% derate, neccesitateing a service regen.
biggest issues are in extreme cold weather running #2 fuel. all the EFI engines use a 2 micron fuel filter that doesnt "like" cold fuel.
using a 50/50 mix of #2 & #1 fuel helps the fuel flow through the filter.
bobcat has added a fuel warming curcuit to bypass the fuel cooler in cold weather on the doosan engines.
:drinkup
We took delivery of our new doosan equipped s650 in mid November. I wish we would have never traded our last machine in. To start, we are a snow removal company and leave our 2 machines outside and plugged in. We have only had our Kubota equipped machines gel up once in severe cold (-25 or lower). Our doosan has been in the shop more than we have run it this winter. We started running 50/50 with schaeffers additive following the instructions of the dealer and it still wouldn't run under 15 degrees. After 4 new fuel filters, 3 trips to dealer, and 2 complete tank and fuel line clearances we have been told we must run straight #1 fuel. What a pain in the ass! Nobody sells it at a pump and we have no way to keep a tank on location. I am totally fed up with this doosan B.S. It starts fine and runs for 10-15 mins after warm up then it will die. That is how it has occurred every time. Barely runs long enough to get it on the trailer. Machine only has 70 hours today and at least 10 of that has been trying to figure the problems out!
Also when you start the machine it takes a long time before you can even throttle up the machine due to the cold weather protection and this occurred above 40 degrees and lasted almost 5 mins even at that temp.
Also when you start the machine it takes a long time before you can even throttle up the machine due to the cold weather protection and this occurred above 40 degrees and lasted almost 5 mins even at that temp.
We have been life long bobcat customers but this issue has me out testing other brands. As much as I like the machine it has proven to be unreliable when we need it the most. Bobcat has really disappointed a very loyal customer with this one!
By the way since the last tank drain we have used strictly #1 fuel and it has only happened once. That was the day after getting it back. The service tech came and looked it over and replaced another almost $100 fuel filter and it has been ok.
The fact that it starts fine then acts up when used the dealer thinks it's not being caused by gelling but can't explain what's going on. The codes have not indicated it was a gelling issue. He thinks it's possibly related to the injectors.
This is actually fairly common with the new Doosan engines according to the Bobcat salesman I used to sell with. As I said earlier, the new engines do not have a DPF and the engine exhaust must be hot to burn the ash since there is no filter to catch it. This is a problem in cold weather and it causes the engine to derate so it doesn't produce as much particulate matter (ash). They also use a very fine fuel filter (2 micron) and highly recommend filtered fuel not out of plastic cans or anything that might be slightly dirty. He has customers complaining of derated engines for up to an hour here in Wisconsin.
That would probably be good. Very small fuel filter tolerance.
Terryz
Well-Known Member
Have you tried blocking 1/3 to 1/2 of the radiator off with cardboard or something similar? We have been doing it for years for snow removal; keeps engine at operating temp and the cab warm. Terry
durallymax
Senior Member
I'd take a DPF over the Doosan solution anyday from what I've heard. Been dealing with DPF's on stuff for awhile and while it sounds like a bad idea, they haven't been. Early ones were, but they're pretty refined now. Bad operators can still cause issues as you elude to. Why are the operators ignoring the regen? Are some brands still unable to accomplish a working regen? The Cat's using the 3.3 Kubota with DPF have a few levels, first they will flash that it needs to regen and you simply run the machine above half throttle while continuing to work, or let it idle and walk away, after a short time period it will do it on its own. The next stage is a parked regen, if you continually ignore the warnings leading up to it. If you keep ignoring it, eventually you will get shut down and need a service tech to do one. It takes a lot to get to that stage though. Ours is over 400hrs now with operators that would not understand the regen process at all. None have asked about the light either so either its asking and they just ignore it, or it hasn't needed to yet. I find it pretty unlikely in 400hrs it hasn't needed to. Other's and myself do run it from time to time and haven't noticed regen warnings either. It does not have a way to see the number of regens in the display. Of course you also always have the passive regens where you work it hard enough to create enough heat for a regen without any assistance. We don't work the machine very hard but it sits in solid dust, so it does make some heat from time to time.
The DPF is not the big mean guy everyone seems to make it out to be.
Never had any fuel issues on our Kubota equipped machine either, we avoid blending #1 until sub zero temps. Additives put in by supplier keep issues away until then.