Start up oil pressure, takes too long for the low pressure light to go out?

terryjm1

Well-known member
Jan 23, 2011
1,486
375
I have this D1 I have been working on running really well now. However, we recently had our first couple of really cold days this winter. At start up it now takes longer than I like after it sits overnight for the oil light to go off. Each of the last two mornings, about 25 degrees, the oil light has stayed on more than a few seconds after start up. It starts right up, hardly turning over at all.

The engine has around 130,000 miles but runs smooth and surprisingly quiet with next to real valve train or other noise, even at start up.

Is slow oil pressure build up usually caused by a worn oil pump or sludge in the oil pan?

I have been told removing the oil pan on these isn’t a horrible job. Do you need to raise the engine? Anything else need to come out / off to get the pan off? I also have a really nice timing cover with next to no wear in the oil pump housing but want to save it for another engine build. How likely is it the oil pump housing is worn out at 130,000 miles?

The previous owner changed the oil about 1000 miles ago. It is still quite clean. I’m wondering if he put 20w50 oil in it and maybe changing to 10w30 would help?
 

boxster

Well-known member
Jun 1, 2009
443
88
Fallbrook Ca.
When jacking up your D1 to remove oil pan, position jack stands under the frame and lower the front axle for clearance, you can inspect the oil pick up tube, remove the front cover inspect t/c and gear and open up oil pump cover and inspect for broken gears and scored front cover which can contribute to low oil pressure.
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
Like Boxster said, if you lift from the frame to extend the suspensoir the oil pan will come out easily.
Hard telling why it’s slow to build pressure. Easiest is oil that’s too thick, then the valve in the oil pump, then loose clearances I suppose. Not sure I would worry about it till it starts making noise. Maybe it’s just the switch? Probably should put an oil pressure gauge on it.
 
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Jimmy

Well-known member
Apr 10, 2006
740
64
Aurora, CO
I stopped having the long oil light at startup on cold mornings when I switched from 15W to 5W. Though, when I say cold I mean single digits, working a mid shift, and firing it up before the sun comes up.
 

Rangeroversurfer

Active member
Jan 16, 2013
40
13
Alaska
I have this D1 I have been working on running really well now. However, we recently had our first couple of really cold days this winter. At start up it now takes longer than I like after it sits overnight for the oil light to go off. Each of the last two mornings, about 25 degrees, the oil light has stayed on more than a few seconds after start up. It starts right up, hardly turning over at all.

The engine has around 130,000 miles but runs smooth and surprisingly quiet with next to real valve train or other noise, even at start up.

Is slow oil pressure build up usually caused by a worn oil pump or sludge in the oil pan?

I have been told removing the oil pan on these isn’t a horrible job. Do you need to raise the engine? Anything else need to come out / off to get the pan off? I also have a really nice timing cover with next to no wear in the oil pump housing but want to save it for another engine build. How likely is it the oil pump housing is worn out at 130,000 miles?

The previous owner changed the oil about 1000 miles ago. It is still quite clean. I’m wondering if he put 20w50 oil in it and maybe changing to 10w30 would help?
Hello Terry,

I wanted to chime in as I also had that problem, as we lived in Anchorage, Alaska for 13 years. So I removed the oil pan on the Discovery and RRC's and cleaned everything out real well, and made sure the oil pick up tube area was clean and free of obstruction. I also had all our cars winterized. our Rovers had a battery blanket, battery trickle chargers, and Block heaters that kept the coolant warm and also an oil pan heater which had self adhesive, but I also placed used high temp adhesive to make sure it stayed on. I also did not use the Rotella 15W40 in the dead of winter as it was too thick, so I ran a lighter weight oil in the winter, but not synthetic as that was a terrible experience. Thanks for all the tips and useful information that you share, very much appreciated. Thank You
 
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terryjm1

Well-known member
Jan 23, 2011
1,486
375
A while back I installed an engine pulled from a flood salvage vehicle that had been untouched for over 15 years, in another D1. It looked like hell on the outside and I expected something similar on the inside. For example, the clutch disk was rusted to the input shaft on the transmission. It was a true battle to separate the engine from the gearbox. After 2 hours of the battle the clutch disc center separated from the outer part and I got them apart. When I removed the intake, I poked my finger through the valley pan gasket as it was paper thin from rust. When I took the engine apart to inspect it and replace gaskets, the short block looked like new on the inside and it has turned out to be a great engine. The heads needed some work though. The valve seats, on the ones that were open during its 15 year plus hibernation needed lapping and one valve needed to be replaced. All of the valves were a bit tight in the guides as well.

While the short block was very clean overall, even at 27,000 miles there was sludge at the bottom of the pan. It wasn’t a huge amount but compared to the rest of the inside of the engine it was more than I would have expected.

For now, I’m going to try thinner oil. Regardless if it solves the problem or not, sometime in the not too distant future I will drop the pan, pull the timing cover, and clean everything. It needs new gaskets anyway and I’m sure the timing chain is plenty stretched out. Hindsight being what it is, considering everything I have already done to the engine, I should have pulled the engine and refreshed everything on an engine stand.

I will post back after the oil change and eventually when I pull the pan and timing cover.
 

robbyb20

Well-known member
Oct 2, 2019
227
34
Seattle
Hey Terry - Out of curiosity, how long does it take for the light to go out on a cold morning? Once warmed up, parked and restarted, how long then?

I also struggle with slow pressure buildup on the first start of the day. During summer(80-100), its 3 seconds. In winter (in the pnw), its around 7-8. This year has been colder than my others so far here (35-45).

within the past month, i have dropped the oil pan, spot checked some of the rod bearing caps and they look to be ok, no grooves or excessive wear. I have changed out the oil pump gears, checked the timing cover and back plate for grooves (slight markings but not deep), took the relief valve off to make it wasnt stuck (ordered a new spring from ptschrams website, need to follow up on that).

Ive got some noise at start for about 2 seconds and it goes away. Then once warmed up theres some valve train noise at idle but i dont think it sounds worrisome. I do wonder what is considered acceptable though.

Is everyones oil light really going out the second it starts are am i chasing perfection?
 

terryjm1

Well-known member
Jan 23, 2011
1,486
375
Everyone likes pictures and a video even more… Here is start up today, 20 degrees. By my count, 13 seconds.


When warmed up the light at restart goes out almost immediately. On warm days, I’d guess a few seconds.
 
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boxster

Well-known member
Jun 1, 2009
443
88
Fallbrook Ca.
Hey Terry - Out of curiosity, how long does it take for the light to go out on a cold morning? Once warmed up, parked and restarted, how long then?

I also struggle with slow pressure buildup on the first start of the day. During summer(80-100), its 3 seconds. In winter (in the pnw), its around 7-8. This year has been colder than my others so far here (35-45).

within the past month, i have dropped the oil pan, spot checked some of the rod bearing caps and they look to be ok, no grooves or excessive wear. I have changed out the oil pump gears, checked the timing cover and back plate for grooves (slight markings but not deep), took the relief valve off to make it wasnt stuck (ordered a new spring from ptschrams website, need to follow up on that).

Ive got some noise at start for about 2 seconds and it goes away. Then once warmed up theres some valve train noise at idle but i dont think it sounds worrisome. I do wonder what is considered acceptable though.

Is everyones oil light really going out the second it starts are am i chasing perfection?
Everyone likes pictures and a video even more… Here is start up today, 20 degrees.


When warmed up the light at restart goes out almost immediately. On warm days, I’d guess a few seconds.
Everyone likes pictures and a video even more… Here is start up today, 20 degrees.


When warmed up the light at restart goes out almost immediately. On warm days, I’d guess a few seconds.
Like the White
 

terryjm1

Well-known member
Jan 23, 2011
1,486
375
“Like the” White Snake” music!”

Classic rock is my only real choice for “free” radio here in the D1s. (We have satellite radio in the newer vehicles.) We are at high elevation with a mountain blocking most radio stations. Fortunately, I like classic rock and it is a really good station. My only other choice for music is a radio station in Spanish, which occasionally I do listen to but aside from that it’s only hard core religious talk radio. I already worry enough about the world. As such, my radio rarely changes from classic rock.
 
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Disco95

Well-known member
Mar 20, 2020
51
21
Portland, OR
You can find my similar thread here someplace. I replaced the switch to no effect. Confirmed with external gauge at filter housing. Dropped pan and pulled cover (spring a coolant leak so had to go in anyways), checked relief valve, replaced o-rings. Didn’t find anything obvious. Pretty sure the light goes out a little quicker than before but still depends on temp. If not normal it sure seems to be common on these D1s. Mine’s quiet on startup but does have a little valve clatter now and then. Rotella 15-40 but next time might try 5w40 T5.

Here’s my before video:

Will update if it blows up one morning ;)

Cheers,
joe b
pdx or
 
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terryjm1

Well-known member
Jan 23, 2011
1,486
375
You can find my similar thread here someplace. I replaced the switch to no effect. Confirmed with external gauge at filter housing. Dropped pan and pulled cover (spring a coolant leak so had to go in anyways), checked relief valve, replaced o-rings. Didn’t find anything obvious. Pretty sure the light goes out a little quicker than before but still depends on temp. If not normal it sure seems to be common on these D1s. Mine’s quiet on startup but does have a little valve clatter now and then. Rotella 15-40 but next time might try 5w40 T5.

Here’s my before video:

Will update if it blows up one morning ;)

Cheers,
joe b
pdx or
I have a couple jugs of 5w40 I was going to use in another vehicle. I’m going to give that a try.
 

Flyfish

Well-known member
Oct 29, 2004
1,402
212
52
St. Louis
I have a couple jugs of 5w40 I was going to use in another vehicle. I’m going to give that a try.
In my head, a lighter weight oil like 5w would build less pressure than 15w, a heavier weight. Could be 100% wrong so let us know.
 

Blueboy

Well-known member
Apr 20, 2004
3,205
459
Back in the USA; Rockwood, PA
In my head, a lighter weight oil like 5w would build less pressure than 15w, a heavier weight. Could be 100% wrong so let us know.
Yes felt the same so use Rotella 10w30 in the Winter here in W. PA. My light takes a bit to go out even in the Summer with Rotella 15w40. After doing what most have mentioned just living with it. My mechanic told me the engine is really clean inside so guess the 3k mile oil/filter change is paying off.
 

Flyfish

Well-known member
Oct 29, 2004
1,402
212
52
St. Louis
In my head, a lighter weight oil like 5w would build less pressure than 15w, a heavier weight. Could be 100% wrong so let us know.
Since pressure is a function of flow and restriction, it would be interesting to see a test of the cold start properties between the two oils. 5w provides more flow and 15w provides more restriction.

So it would be interesting to know what’s the sweet spot between the two that gives you the best of both.
 
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StangGT5

Well-known member
Feb 4, 2019
295
130
Atlanta, GA
I swear by 15w40 in these trucks, but it is too thick for truly cold climates. Like others have said, consider switching to 5-30/40 during winter and see what it does. I picked up an AMG a while back that spec'd 0-40. It went against my instinct to run that, but it's required for quick lubrication on start up.
 
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