diesel runs rough on start-up

[SSdoxie]

Interesting. My Bobcat has an ignition key position for pre-heat and doesn't have to be held there. Guess they figure the owners will turn it on, then sip their coffee until the heating light goes out.

Dr Zinz, The Bobcat tractor preheat is based more on time than heat, will only run for about 45 seconds max then shut off regardless of engine temp. When really cold may have cycle the switch to reset the preheat or turn switch to the left for manual pre-heat. Loaders & excavators are are temp sensitive, will run pre-heat for up 45 seconds, shut off then restart the cycle automatically until hot enough to start.

With either glow plug or air intake system it is best to cycle it for 30 - 45 seconds on, off for 10 - 15 seconds then back on. Repeat as necessary depending on temps. With air intake systems, I like to cycle it once or twice then jog starter to draw some of warmed air into the engine then pre-heat again to warm up more cold air versus heating same air to hotter temp.

 

[wolc123]

When I bought my 4120 (6) years ago, I believe the cost of the block-heater was $70. The dealer did not charge me which was understandable considering the $22k I gave him for the tractor/loader. I imagine they may be up to $100 today if you buy from JD. Still a cheap way to add many hours to the life of your engine.

 

[Glen Watkins]

You sure you don't have one installed right? If you do it would be down near the dipstick.

 

[JD 4520]

When I bought my 4120 (6) years ago, I believe the cost of the block-heater was $70. The dealer did not charge me which was understandable considering the $22k I gave him for the tractor/loader. I imagine they may be up to $100 today if you buy from JD. Still a cheap way to add many hours to the life of your engine.

Thanks again for the info. No I don't have a block heater as I brought my tractor up from the southwest where they weren't needed. Ordering tomorrow. From some quick research it appears that there are a few heater styles or options. Any preference or does JD only have one solution? Given after market installation, is there anything to be aware of? I am looking at the "freeze plug" style heater.

 

[SPYDERLK]

Dr Zinz, The Bobcat tractor preheat is based more on time than heat, will only run for about 45 seconds max then shut off regardless of engine temp. When really cold may have cycle the switch to reset the preheat or turn switch to the left for manual pre-heat. Loaders & excavators are are temp sensitive, will run pre-heat for up 45 seconds, shut off then restart the cycle automatically until hot enough to start.

With either glow plug or air intake system it is best to cycle it for 30 - 45 seconds on, off for 10 - 15 seconds then back on. Repeat as necessary depending on temps. With air intake systems, I like to cycle it once or twice then jog starter to draw some of warmed air into the engine then pre-heat again to warm up more cold air versus heating same air to hotter temp.

Great idea! I might be able to use it when really cold -near 0F. Otherwise, the 7520 just seems to start so quick on warmed air that it will fire up before I can let off the key. :confused3: ... I use a 5w-40 oil so crankcase heating is not an issue for oil delivery.
larry

 

[JD 4520]

Yesterday I ordered a block heater from the local dealer. It is $150 and had to be ordered. I was a bit surprised by the price. Hopefully it's straight forward on installing. Seems like after market prices on the Internet for a heater is $45 - 80. Oh well.