Oil pressure fluctuation - 2003 Yukon

[DonnieBrasco]

2003 Yukon with ~215K miles. Never noticed any issues or fluctuations with my oil pressure. Right after cranking up it bumps up to dead center at 40 and holds there. This weekend I started noticing some fluctuation. Now, I was overdue for an oil change. Not extremely overdue, but it had been around 7k since my last change. As soon as I got back in town yesterday I changed the oil. The pressure fluctuation is minor. When I am idling it drops just below 40. When the RPMs go up on acceleration, it bumps up a little over 40, but it never goes over ~60. If I'm cruising around 70-75 mph, the oil pressure stays around 55 or so.

Also, when I climbed under last night to change the oil, I noticed around the drain plug and all around the oil pan was pretty oily. I haven't noticed that much oil build up before. So it's possible I have a minor leak? I never notice oil under the car after sitting overnight or in the garage at work. Maybe a drop or two, but nothing significant.

1. Is oil pressure fluctuation as described above an emergency situation or should I just watch it and see if it gets worse?
2. What could some of the issues be? I was wondering if it was sludge buildup at the intake on the oil pump.

I probably have a year or less left in this Yukon, i.e., I don't want to do a ton of maintenance ($$$) if I'm just going to get rid of it later this year. I just want to keep it able to get me from point A to point B until I'm ready to get a newer one. Thanks for any advice.

 

[clandr1]

1. Is oil pressure fluctuation as described above an emergency situation or should I just watch it and see if it gets worse?
2. What could some of the issues be? I was wondering if it was sludge buildup at the intake on the oil pump.

2005 with 144k here.

1. In my experience, it is normal for it to bounce between 30 and 80, depending on environmental conditions and RPMs. When it is cold outside and I first start it in the morning, the pressure jumps to 60-80 when I'm on the throttle getting on the highway on my commute to work. Once it warms up and the oil becomes thinner, the pressure really never gets above 60.
2. Did you change oil weights or types (synth vs conv) when you changed it? Did you use a different filter?

 

[DonnieBrasco]

2005 with 144k here.

1. In my experience, it is normal for it to bounce between 30 and 80, depending on environmental conditions and RPMs. When it is cold outside and I first start it in the morning, the pressure jumps to 60-80 when I'm on the throttle getting on the highway on my commute to work. Once it warms up and the oil becomes thinner, the pressure really never gets above 60.
2. Did you change oil weights or types (synth vs conv) when you changed it? Did you use a different filter?

Thanks for the advice. I don't think I changed the weight. I know I didn't change the type, I always use high mileage/synth stuff. I definitely used a different filter. I like using the Wix filters, but I can't always find them when I go to get my oil, so I end up using some different ones.

I think it's doing ok now. I think the previous oil was just really really at the end of its life and was breaking down. And that coupled with the fact that I had never noticed the pressure move before kind of freaked me out. If I can get one more year out of this whip I'll be happy!

 

[clandr1]

I think that as long as it doesn't go below 30 or above 80 for an extended period of time, it'll be fine. You're probably right - the oil might have just been so old that it lost it's ability to change it's viscosity to various temperatures which is why your oil pressure was always constant.