2000 Chevy C3500 6.5L diesel

[Dylanviey]

I'm a ford guy and have been looking for a new work truck for a while. (all 3 of mine have had a major issue that took them off the road in the past few months.)

Found a Chevy c3500 utility body no rust with the 6.5L diesel for under $4k so I figured I would switch to a Chevy for that price tag and a vehicle already set up how I want my work truck to be set up. (I work as a jack of all trades for a small railroad.) Also as a bonus it's hard to tell from the photos but it's custom painted Brunswick green which is the same color the painted the engines for one of my favorite railroads. Haha (Pennsylvania railroad)

I've been researching the downfalls and bullet proofing the engine and had a few questions about what other people do. I'm used to the ford 7.3 but not this engine.

The main thing I was wondering about was the vacuum pump delete.

So far what I have found was remove the vacuum pump and install another way to govern the turbo. But they don't really talk about how to govern the turbo, just talk about removing the pump. I was wondering what products other people have used and how they did it to govern the turbo. Last thing I want to do is blow up the turbo.

Also I was wondering has anyone ever converted/replaced a vacuum pump and turned it into an air compressor. Figured that would be better for me so I don't need to get a new serpentine belt. (the one it came with was shot but the previous owner gave me a new one for free.) if they ever converted a vacuum pump to what did you do. and what if you bought an bolt on compressor what did you buy? I remember someone telling me about converting a vacuum pump into a compressor but never really looked into it.

I would like to transfer my auto snow chains from my old work truck to this one but I need an air source for them to work. My old truck had a 12v compressor but if I can get a higher CFM one and mount it to the engine I would love to set it up air tools as well for my work.


Also I just noticed this today but the oil pressure has started fluctuating. When idling it sits around 20psi cruising around 40psi and accelerating around 60psi Is this normal? if not what is the most likely cause? again I'm not very knowledgeable about this engine or Chevy's in general.

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[u2slow]

Oil pressure tends to be rpm dependent. I would expect more than 20psi at idle on a fresh engine, but I wouldn't be concerned until below 10.

My memory is failing on the turbo. Is it wastegated? Other turbos use boost pressure via an actuator, or against a spring to open the wastgate.

You may need vacuum for the heater box controls and/or the 4wd system. An electric one from a Superduty can probably be substituted.

Be gentle with the 6.5. They are not as rugged as a 6.9/7.3.

 

[snicklas]

Calvin (towcat) loved the 6.5.... Another option for the turbo... a Ford IDI turbo (banks I think) would bolt right in place. I think he talked about it on here... just have to do some searching.

Is this new enough to have the PMD? If so, most relocate it off the IP....

I know one big this with the 6.5/6.5 is DO NOT OVERHEAT them.... that will kill one quickly.....

 

[Dylanviey]

Oil pressure tends to be rpm dependent. I would expect more than 20psi at idle on a fresh engine, but I wouldn't be concerned until below 10.

A had a feeling but I wasn't sure. like I said I am not used to this engine and I'm used to the pressure moving a little like maybe 5 or 10 PSI ether direction but not a 20PSI swing. What would cause such a huge swing? worn out oil pump? I haven't given the engine an oil change yet was wondering if maybe that would fix it. I don't even know the last time it had one yet. Was planning on doing that in a week after I had it fully equipped for my needs. And cant really do that until new door handles with locks show up. It kind of bugs me to see that type of movement on the dash while driving.

The only thing wrong with the truck is it looks like King Kong went on a rampage on the interior and ripped every door handle off screwed them back on then ripped them off again. And the keys for the toolboxes where missing and a couple of handles are sloppy so I ordered new handles with locks for that as well. Until that I'm just painting everything in bed liner to keep it rust free and going to be installing a crane onto the back.

My memory is failing on the turbo. Is it wastegated? Other turbos use boost pressure via an actuator, or against a spring to open the wastgate.

You may need vacuum for the heater box controls and/or the 4wd system. An electric one from a Superduty can probably be substituted.

Be gentle with the 6.5. They are not as rugged as a 6.9/7.3.

And I haven't really looked at my truck other then replacing the serpentine belt and finding a improperly attached ground wire which I will fix later. But from what I have read/watched so far the turbo is waste gated and the only thing the vacuum pump does is control that. but they don't really talk about replacing the vacuum with something else. They just say get rid of it and find another way to control the turbo. They don't mention heater box controls or anything else vacuum which doesn't make sense to me.

I think I'm planning on skipping that part of the bullet proofing unless I can find other people who has done it. Everything else is very straight forward. And I was hoping that if I did then maybe I could replace the pump with a high capacity compressor.

 

[Dylanviey]

Calvin (towcat) loved the 6.5.... Another option for the turbo... a Ford IDI turbo (banks I think) would bolt right in place. I think he talked about it on here... just have to do some searching.

Is this new enough to have the PMD? If so, most relocate it off the IP....

I know one big this with the 6.5/6.5 is DO NOT OVERHEAT them.... that will kill one quickly.....

The PMD was one of the things I saw to relocate. I defiantly plan on doing that. from looking at everything it looks like the previous owner was really on the ball with maintaining this vehicle. He had it since 50k miles and drove it until 300k. I had the dealer salesman start it while I watched the engine. And he didn't even wait for the glow plugs to heat up and instantly started cranking it and it instantly fired right up which I though was impressive for a diesel.

The only thing I noticed odd was because the serpentine belt was bad the vacuum pump wouldn't turn and the belt just slipped for like a good 2 seconds until the belt finally got a grab and it spooled up. Which I though was odd. Didn't think that the belt would slip there if it was bad. Normally I feel it slips on the alternator or AC compressor.

It looks like the guy already replaced the thermostat from one set to 200 to one set to 180 which is one of the things I saw to do. Keep the engine cool. I'm hoping the PMD is also relocated already but I haven't dug through the engine yet to check it.

 

[u2slow]

Engine wear is where your oil pressure has gone. It has mostly affected the idle psi. Thankfully it still presses up nice with revs.

Here is a wastegate spring kit:
http://www.heathdiesel.com/turbo-master-gm96.html

 

[Dylanviey]

Engine wear is where your oil pressure has gone. It has mostly affected the idle psi. Thankfully it still presses up nice with revs.

Here is a wastegate spring kit:
http://www.heathdiesel.com/turbo-master-gm96.html

Thanks!

BTW is there something that can be done to get the idle oil pressure up. I now know it's not a concern yet and that's a relief. Would love to know how to increase the longevity of the engine or what I will need to do in the future when it does drop to low. I expect it's probably multiple things warn out at 300k miles. I'm pretty good with anything external on an engine but my knowledge starts to lack internally on engine.

I like replacing things before they fail especially after the last few months failures. Had my ambulance start to fall apart so I took it out of service for a rebuild (needed trans work and a new rear axle among other things). Drove my bronco for a few months then had the front left tire blow out on the highway causing a over 3k bill just to get it back on the road. (no body damage only mechanical hy-rail gear saved it when I crashed nose first into a dirt V ditch) Bought a Jeep Cherokee to hold me over until I could fix the bronco. then had something break in front axle from getting stuck so many times during the large snow storm about a month back when my town decided to stop plowing almost all the streets except the main road through town leaving over 1ft of snow on the roads. (was snowed in for over a week until the town finally sent their front end loader down my street.)

 

[u2slow]

Change the oil pump. Check the piston squirters are all still in place. If that doesn't help, you're looking at renewing main bearing shells. Next would be cam bearings....

At 300k miles, it's rebuild time anyway.

Edit: could try a thicker oil as a bandaid; like straight grade sae 30 or 40 if your climate allows.

 

[79jasper]

Before getting all bent out of shape, what is factory spec for oil pressure?

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[u2slow]

Oil pressure discussion here

https://www.dieselplace.com/threads/normal-operating-oil-pressure-of-a-6-5-new-user.185590/

 

[79jasper]

Thanks, been awhile since I was around the gm stuff.
So according to that, within the "norm."

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[Dylanviey]

Thanks.

I'll probably try a new oil pump later in the year and see if that helps at all. I'm hoping to get this engine to 350k or 400k before having to do anything major to it. (key work hoping haha) I'm just not used to an oil pressure gauge swinging that much. With the past year of vehicles failures I don't have any money for a rebuild at the moment. Doesn't help my job has been mostly shut down with me working minimum hours. Although it is allowing me to work on this truck all day every day. haha. Spent the first day having it prepping for painting 2nd day finish prepping then started painting and today since it was to cold to paint I start fixing the passenger side door that looked like a gorilla tried ripping it off it's hinges. Ended up taking a jack and jacking the truck by the door to get it to line up right again and stop bouncing off of the rocker. (after new hinge pins and shimming the door up with washers)

In a few weeks my work is going to open back up and I'll get to get paid to tinker on my truck. haha. Good thing I don't need to worry about running out of things to tinker with this truck.

EDIT: This kind of sounds like a noob question but where would a good place to be to post a build thread about this truck? I assume Chevy and GMC are about the same? Again I'm a ford guy and never paid any attention to Chevys. I'm having a hard time finding interior parts for this vehicle.

 

[79jasper]

They are the same. GMC is usually just the fancier version.
Also, if you're used to fords, it will seem like the guage moves a lot. Beings ford didn't use a real gauge, it's just a idiot light ran off a pressure switch.
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[Dylanviey]

They are the same. GMC is usually just the fancier version.
Also, if you're used to fords, it will seem like the guage moves a lot. Beings ford didn't use a real gauge, it's just a idiot light ran off a pressure switch.
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I always though that with all of my gauges on my trucks. They never gave you real information other then the engine temp gauge.

on my ambulance it had some kind of box (forget what its name was) that would display a digital read out of the RPMs and also controlled the RPMS and monitored the battery's. (was real helpful for jump starting stuff at work because it would auto rev as soon as I hooked the battery leads to the other piece of equipment.) But if you pressed a button it would give you a read out of the power to the battery's. and I noticed the amp meter on the panel and the amps on the box never matched up and felt like the panel gauge only had 2 positions. engine running and engine not running.

 

[79jasper]

Yeah. That's the auxiliary idle controller.

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