One Piece at a Time: My 1985 Diesel Suburban

[campfire]

Had the ceremonial unveiling today. 3yo says:

"MOG Truck!"
...
...
<pause>
...
...
"But...the wheel is broken. It came off the bottom of the truck."

She's referring to the bottom right corner of the image.

But I'd call that a successful roll-out. Cheeseyoop family approves.

 

[Scribbles]

Got mine, I really appreciated the personal touches, far more than expected. I love it, plus...it’s black, I probably should’ve ordered two, one for work one for play.

 

[AgDieseler]

Shirt looks great...thanks!

Thank you. The artist is really talented, and we worked well together through the design process.

Got mine too, thanks!

Awesome!

Got mine! Very quality shirt. Fits true to size just as you said.

So glad you like it.

I wish I could take credit for the selection, but it’s the shirt brand that was issued to us for Trail to SEMA. I just like the feel of it and that it was made with US cotton. That first one has stood up to a series of washes (on cold).

Thanks for the shirt David! Can’t wait to show it off.

You bet! Happy to have one in the hands of a 6.5er.

Wore mine to work, folks asked if it was my burb. I told them it's what mine wants to be when it grows up. Lol .

I did share the story behind it. The older guys liked it...

You really hit on it. The stories are what make our trucks interesting.

Had the ceremonial unveiling today. 3yo says:

"MOG Truck!"
...
...
<pause>
...
...
"But...the wheel is broken. It came off the bottom of the truck."

She's referring to the bottom right corner of the image.

But I'd call that a successful roll-out. Cheeseyoop family approves.

For a 3 year old, that’s a solid assessment of something that’s an artists design rather than a photo. Smart girl.

I’m so glad you like it, and have absolute confidence it will get used, well.

Yep, mine showed up today! Looks pretty good.

Thanks man. It looks best when the wearer is shredding tires in a boosted 6.5-powered step side!

Got mine, I really appreciated the personal touches, far more than expected. I love it, plus...it’s black, I probably should’ve ordered two, one for work one for play.

Happy to share, and thank you again. It’s a very personal project.

David

 

[AugustDiesel]

When my boys saw it, they pointed at the burb and said excitedly, “That’s daddy’s truck!” I told them mine would be that cool someday.

They also say that about every truck on the cover of every LMC magazine. I guess that’s an indication of their deep appreciation for square bodies. #startemwhiletheyreyoung

 

[AgDieseler]

It’s that time of year when I prep for the annual granite run in central Texas. We’re hitting up Wolf Caves again, and fortunately, my checklist is short:

• Replace a split 1350
• Fix the Magnum shifter - keeps popping out of high
• Change the oil
• Charge the AC

I like short lists.

David

 

[imiceman44]

It’s that time of year when I prep for the annual granite run in central Texas. We’re hitting up Wolf Caves again, and fortunately, my checklist is short:

• Replace a split 1350
• Fix the Magnum shifter - keeps popping out of high
• Change the oil
• Charge the AC

I like short lists.

David

I have a very short list:
Build the suburban

 

[AgDieseler]

Let’s see how this stuff does.


Rotella and Delo must have a different formula these days. They can’t seem to hold their viscosity running down the highway. I’m not working it hard at all - 65MPH cruise at 500-600EGT - and oil pressure starts at 40 then slacks to 35. As soon as I come off the highway, oil cools a bit, and pressure is right back up to 40. It was even more pronounced on the mountain passes late last year.

I remember when off the shelf 15w-40 would perform, but I’m super disappointed. Let’s see how some fancy stuff performs on the road to Wolf Caves.

David

 

[KirsL]

If you're only loosing 5 psi when under hot load. I wouldn't be too worried about it. 35 under load when hot is very good. GM specs down to 20 under load.

What's your hot idle pressure? Spec is down to basically 1 psi per 100 rpm. Around 20 is preferred.

 

[AgDieseler]

If you're only loosing 5 psi when under hot load. I wouldn't be too worried about it. 35 under load when hot is very good. GM specs down to 20 under load.

What's your hot idle pressure? Spec is down to basically 1 psi per 100 rpm. Around 20 is preferred.

Good feedback. Cold idle is 60, standard hot idle is just a tick over 20, and a really hot idle after making a long grade has been as low as 15. Each time, the oil cools and recovers to the standard 20+.

I guess I’m quibbling, but an unloaded highway cruise on flat terrain doesn’t fall under my definition of “under load.” Maybe it should given the truck’s size. In my mind, oil pressure should remain more stable during that operation. I reserve the right to be wrong.

This will be a decent A-B test. We hit the road tomorrow.

David

 

[mrk5]

Sometimes it's okay to do things just because they make us feel better whether or not it's really needed. Then the drive is more relaxing.

 

[GWeakland620]

Sometimes it's okay to do things just because they make us feel better whether or not it's really needed. Then the drive is more relaxing.

Those are some good words sir. I may pass that on to my wife the next time I have a large purchase to make.

 

[AugustDiesel]

Those are some good words sir. I may pass that on to my wife the next time I have a large purchase to make.

Lol. I’m going to do the same.

Good feedback. Cold idle is 60, standard hot idle is just a tick over 20, and a really hot idle after making a long grade has been as low as 15. Each time, the oil cools and recovers to the standard 20+.

I guess I’m quibbling, but an unloaded highway cruise on flat terrain doesn’t fall under my definition of “under load.” Maybe it should given the truck’s size. In my mind, oil pressure should remain more stable during that operation. I reserve the right to be wrong.

This will be a decent A-B test. We hit the road tomorrow.

David

Those are interesting numbers. But then again, I’m just a novice. My 6.5 NA has the same 60 cold idle, but then hot idle is about 35-38.

 

[campfire]

Those are interesting numbers. But then again, I’m just a novice. My 6.5 NA has the same 60 cold idle, but then hot idle is about 35-38.

I'd get pretty alarmed if mine reached 20psi. I expect 60 cold and pretty close to that when hot. 40 seems too low.

My trucks aren't your truck, nor are my usage patterns the same as yours. But 20PSI...ain't nobody got time for that!


Unless you're David Freiburger...

 

[campfire]

I use basic cheapie Mobil Delvac 1300 Super (15W40), for what it's worth.

 

[noJeepshere]

Good feedback. Cold idle is 60, standard hot idle is just a tick over 20, and a really hot idle after making a long grade has been as low as 15. Each time, the oil cools and recovers to the standard 20+.

I guess I’m quibbling, but an unloaded highway cruise on flat terrain doesn’t fall under my definition of “under load.” Maybe it should given the truck’s size. In my mind, oil pressure should remain more stable during that operation. I reserve the right to be wrong.

This will be a decent A-B test. We hit the road tomorrow.

David

Fwiw, when I'm towing with my Duramax at highway speeds, the egt's are in the 600° range, and cruising empty they're closer to 450°, so it seems your "light" cruising is another's under load, which would explain why your oil seems to be getting thin while driving. But then, the oil pressure in mine has never been less than 60psi when above 1,000 rpm cold or hot.

 

[AgDieseler]

I'd get pretty alarmed if mine reached 20psi. I expect 60 cold and pretty close to that when hot. 40 seems too low.

My trucks aren't your truck, nor are my usage patterns the same as yours. But 20PSI...ain't nobody got time for that!


Unless you're David Freiburger...

I observed my oil pressure readings change when I switched from stock to the Dakota Digital cluster. It used to peg the factory gauge past 80 when cold, and 60 was a hot cruise, so we might not have a good basis for comparison.

Fwiw, when I'm towing with my Duramax at highway speeds, the egt's are in the 600° range, and cruising empty they're closer to 450°, so it seems your "light" cruising is another's under load, which would explain why your oil seems to be getting thin while driving. But then, the oil pressure in mine has never been less than 60psi when above 1,000 rpm cold or hot.

You’re probably right. The truck has stunning aero.

David

 

[mrk5]

I've decided this is true of the crew cab. It needs the 454 just to haul its heavy self around. I'll bet your suburban isn't much lighter.

One of my favorite things about my 2 older Chevy's is they have mechanical oil pressure gauges, that way there's no wondering if the number is true.

 

[KirsL]

I'd get pretty alarmed if mine reached 20psi. I expect 60 cold and pretty close to that when hot. 40 seems too low.

My trucks aren't your truck, nor are my usage patterns the same as yours. But 20PSI...ain't nobody got time for that!


Unless you're David Freiburger...

Your numbers sound normal for still using the stock oil pressure gauge. I wouldn't worry about 20 psi when hot.

 

[6872xtc]

One of my favorite things about my 2 older Chevy's is they have mechanical oil pressure gauges, that way there's no wondering if the number is true.

Mechanical gauges can be incorrect as well. Maybe not as often as electric, but they can be incorrect. The little burdon (?) tube inside can get damaged or the connector to the needle can have issues. I have found gauges with inaccuracies in the lower part of the scale too, most noticable by never going to zero.

I am definitely interested in the outcome of the oil change. It would be interesting to know what the oil temperature was in each situation as well as if there is a difference with the different oils. But keep in mind that it may take a while to notice any difference as often the oil has to spend some time circulating and "plating" the metals in the engine.
I personally wouldn't worry about 20 psi at hot idle if the engine is of a known good condition. I used to watch a big cam 400 Cummins go from 80+ psi cold idle, to 15 hot. It had low pressure, high flow oiling. Oil temperature would sometimes get up to 230* when working it hard, and that's when it was time to back out of it some and drop a gear or 2.
I switched the trucks at work over to a semi-synthetic oil from Schaeffer's 2 years ago and no one has noticed anything on their oil pressure gauge, even though it pumps easier. We had to turn the air pressure down a little on the bulk pump in the shop. Even the guys with ISX Cummins with 6K miles didn't notice when we drained the factory fill Delo.

 

[noJeepshere]

Yeah, 20 is ok if the motor is otherwise healthy. Our big diesels at work (10,000 ci. 16 cylinder monstrosities) when cold, which they rarely are, will hit 100 psi at idle, but when they're warm, they'll run 65-80 psi while running and drop all the way to single digits at idle.