Cold start oil pressure slow to rise: check my thinking

[p m]

FWIW, the oil pressure light turns off roughly at the same time in a 95 Classic with 220kmi and 96 D1 with 270kmi, both with original engines.
Out of two others with 3.9 built out of 4.0 blocks, in one the light goes off in a second, in another - in 2-4.

 

[mlambert1987]

Strange that it goes out, when I had low pressure it started out 40 psi until the oil warmed up, then dropped like a rock. Odd to see the opposite. I’d guess oil pump over worn bearings.

 

[Discoflyer]

I have the same issue with my 2003 d2. Oddly enough, I noticed that if I leave it parked on an incline , nose pointing downhill,I don’t get the red oil light. If it’s parked facing uphill, for a while, the light can be on up to 30 seconds. Yes, I checked the oil level On level ground!
Not sure if I am going to dive into it further as it runs fine afterwards. Has 175,000 miles on it and I am considering an LS swap or “top hat” remanufactured engine so any effort put into this one seems like a waste of time.
sure seems like more oil in the front of the pan makes the difference.
Also, if the light comes on at a cold start ( cold being a relative term in Florida), and it stays on more than ten seconds or so, I found that turning it off for a few seconds then starting again also results in the light going out.

 

[pdxrovermech]

I have the same issue with my 2003 d2. Oddly enough, I noticed that if I leave it parked on an incline , nose pointing downhill,I don’t get the red oil light. If it’s parked facing uphill, for a while, the light can be on up to 30 seconds. Yes, I checked the oil level On level ground!
Not sure if I am going to dive into it further as it runs fine afterwards. Has 175,000 miles on it and I am considering an LS swap or “top hat” remanufactured engine so any effort put into this one seems like a waste of time.
sure seems like more oil in the front of the pan makes the difference.
Also, if the light comes on at a cold start ( cold being a relative term in Florida), and it stays on more than ten seconds or so, I found that turning it off for a few seconds then starting again also results in the light going out.

the oil tube pickup at the block on a d2 is up towards the front which is likely why it varies based on your angle. I would bet the seal on the tube isnt doing its job.

 

[Disco95]

I need to take some scientific-ish measurements, but I should update this thread and mention that all the work in the front cover/oil pan does seem to have helped. The max time is now <10 secs (seat of pants guess) and many cold starts are almost "normal" (couple of secs max). Like I said I didn't find any smoking gun in there, so I can't say what if anything helped. The only obviously worn out things were the pickup gasket (seems less critical on this style pickup than the later ones) and oil cooler o-rings. At least I got something for all my trouble, although I also now have a front crank seal dribble and rear oil pan leak that I'm not sure is new or just more noticeable since I cleaned things up!

Will report back when I get a chance to take some oil pressure readings again.

Cheers,
joe b
pdx or

 

[robertf]

15w40 does that to mine if its below 50ish outside. Ive switched to driven 10w40 because it took too long for the oil light to extinguish in the winter