slow to build oil pressure at start up B7800

rocco611 · Feb 26, 2019

I have a 04 B7800 with about 450 hours on it. I mow with it about 4 times a year and use the loader to to move things around maybe once a month at most, it doesn't get a lot of use. I change the engine oil every couple of years. Recently on cold start after setting overnight or longer it takes 5 seconds for the oil light to go out when started at idle. I Changed the oil, replaced the kubota oil filter with a wix . same issue. I have always used 10w30 diesel oil. I checked the oil pressure today with a oil pressure gauge. cold start, after about 5 seconds at idle the oil pressure came up quickly to 55 psi cold then dropped to 22psi after warm up. at 2000 rpm warm the oil pressure is 50 psi. warm restart , oil pressure comes right up without delay. is this something I need to be concerned about? what could cause this? oil light used to go out as soon as the engine started .

jonsstihl · Feb 27, 2019

mine takes a few seconds to go out also and i'm using 0W-40 synthetic. mine has always done that. I definitely takes more time when it is cold. example summer temps versus winter temps. I think it is normal.

LouNY · Feb 27, 2019

If your oil pump has a pressure bypass it could be leaking,
but quite often being slow to get pressure is too heavy of an oil,
try a 5w-40 or even 0w-40.

dodge man · Feb 27, 2019

I'd also try bumping up my RPM's a little when its cold, and I agree, try a synthetic oil.

rocco611 · Feb 27, 2019

dodge man said:
I'd also try bumping up my RPM's a little when its cold, and I agree, try a synthetic oil.

just thought of something now that you mention Idle rpm, the idle is about 600 rpm, should be 1000 rpm I think , seems to be slower than it used to be. Will adjust it and see how the oil pressure responds.

dodge man · Feb 27, 2019

I'd even throttle it up a little bit more than that, maybe as much as 2000 rpms for a few seconds after starting it.

RalphVa · Feb 27, 2019

rocco611 said:
I have a 04 B7800 with about 450 hours on it. I mow with it about 4 times a year and use the loader to to move things around maybe once a month at most, it doesn't get a lot of use. I change the engine oil every couple of years. Recently on cold start after setting overnight or longer it takes 5 seconds for the oil light to go out when started at idle. I Changed the oil, replaced the kubota oil filter with a wix . same issue. I have always used 10w30 diesel oil. I checked the oil pressure today with a oil pressure gauge. cold start, after about 5 seconds at idle the oil pressure came up quickly to 55 psi cold then dropped to 22psi after warm up. at 2000 rpm warm the oil pressure is 50 psi. warm restart , oil pressure comes right up without delay. is this something I need to be concerned about? what could cause this? oil light used to go out as soon as the engine started .

That 10w30 oil is probably not much better than the old fashioned 30w oil, not good for cold starts. You should use, minimum, a 5w30 oil. I use VW's for their TDIs. They have about 4 different ones. I use the 5w30 for 2010ish VW TDIs.

Online, you can order some M1 0w30 ESP oil for diesels. This would be even better, a a MUCH better oil that what you're using. I think for future changes on both my JD and Isuzu diesels that this is what I'll get.

You can get 0w40 diesel oil at the JD dealership here. It's pretty expensive. The M1 0w30 stuff online would be better.

Ralph

rocco611 · Feb 27, 2019

RalphVa said:
That 10w30 oil is probably not much better than the old fashioned 30w oil, not good for cold starts. You should use, minimum, a 5w30 oil. I use VW's for their TDIs. They have about 4 different ones. I use the 5w30 for 2010ish VW TDIs.

Online, you can order some M1 0w30 ESP oil for diesels. This would be even better, a a MUCH better oil that what you're using. I think for future changes on both my JD and Isuzu diesels that this is what I'll get.

You can get 0w40 diesel oil at the JD dealership here. It's pretty expensive. The M1 0w30 stuff online would be better.

Ralph

I didn't mention I live in Central California. doesn't get very cold here. the viscosity of most 0w and 5w oils is actually higher than the 10w-30 oil I am currently using at temperatures above freezing. appears the 0w and 5w are only thin when its freezing. with the low hours I put on the tractor cost really isn't an issue with engine oil since I change it once every two years or so. I am looking at some different synthetics and comparing viscosity. it doesn't work quite the way I thought it did.

I set the the idle stop on the injection pump to 1000 rpm, it was pretty low just under 600 rpm. started it early this morning oil light went out immediately. Im not sure why the idle rpm decreased over time. I will be switching to a full synthetic at the next oil change. thanks to everyone for the suggestions.