Newbie to 6.5 have questions

Recently bought a 95 3500 with a 6.5 for my 17 year old son and have some questions that I can’t seem to find answers to.

1. While fixing a leaky fuel filter housing I discovered the oil supply line to the turbo came off a splitter where the oil pressure sensor goes. This mass of pipes and fittings rigged together is leaking and I want to return it to stock. Where is the stock oil feed for the turbo? What stock fittings do I need? Anyone have photos?

2. A mechanical injection pump has been fitted by the previous owner for “reliability” should I go back to the electric one ? Upsides/downside? All the original wiring seems to be there still but is a bit of a mess.

3. waste gate is completely disconnected from anything what should I do with this?

4. Stock fuel pump relay has been jumped by a manual switch under the dash I have read this could be my oil pressure sensor but not completely sure

5. Need some photos of stock wire harness routing along the firewall so I can get it back in place

6. Things that I need to check? Engine seems to run really well despite massive fuel leaks and obviously poorly maintained. Started up with one glow cycle in 20 degrees. Anything I need to watch out for?

Hi and Welcome
Othere will /may chime in.
1. That is the stock feed for the turbo
2.No keep the mechanical pump you are way better off,is the tranny an automatic or manual?
3 The Previous owner may have made a mechanical waste gate for the turbo,a couple of reasons for that.One is it's been converted to a mechanical pump,and the vacuum pump may have been deleted.If so you may come across a couple vacuum related issues depending on the tranny.
4. I would contact Kennedy Diesel and get a fuel pump wiring harness from him and install it.
5. Sorry i don't have a truck like that running so i can't provide any pic's,they are all under 4 ft of snow.
6.Clean the cooling stack and make sure your cooling system is clean and working correctly,check thermostat,water pump,fan clutch and clean between the rad and AC condenser.The bottom of the fuel filter has been known to rot out.
You should take some pictures of the mechanical pump,the wastegate from the turbo and the leaky fittings for the turbo and post them.Then some eyes can access the work done.
Enjoy the new truck

1. It looks like a bunch of pipe fittings from Home Depot haha what sealant is best for them? I will get some photos later tonight

2. Yes it’s manual... should I still upgrade the lift pump? If so which one

3. Vacuum pump is gone and waste gate has nothing going to it I assume it’s a pressure regulated waste gate not vacuum as the turbo does currently work

4. I will do that

5. Just don’t see anything on the fire wall to attach the harness too like the google images I’ve seen

6.is the cooling stack the pipe where the thermostat is? Is dual thermostat better or stick with the single? Plan on the upgraded water pump and fan

How do you post photos to this forum?

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Originally Posted by Polarisrmk

How do you post photos to this forum?

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Click the "Insert Image" icon at the top of the text editor you use to reply here. Select the source (URL or your device). Follow the instructions. If you are using a photo hosting site (Photobucket, etc.), copy the URL from there (refer to their instructions for offsite links), and paste it into the image dialog here. Photos you upload from your device should be automatically process (reduced in size if they are too large, etc.), but sometimes it just doesn't work for one reason or another. Please contact me if this happens.

Attachment 5782

This is what I found when I removed the intake

Homemade upgrade. I've seen worse.

The best thing i have learned for sealing threads is hemp.
You have to put a little time into each set of threads,but i have never had a leak when hemp is used.The hemp swells when it gets in contact with fluids.
But a good quality pipe dope will give good results.Teflon tape is often recommend against because if used improperly it can end up plugging small orifices.
Take a picture of the turbo waste gate the PO may have dealt with it by making it manual controlled.
Lift pump is the pump that supplies the injection pump.The OEM one is as good as any on these trucks.
Cooling stack is what the assorted radiators are called.You will have the rad,maybe a AC condenser. Leaves and stuff build up between the two,oil is bad because it attracts stuffs and builds a mat that air cannot flow through.

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Originally Posted by DmaxMaverick

Homemade upgrade. I've seen worse.

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Do you have any photos or parts list of what is should look like? is leaking pretty badly

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Originally Posted by Yukon6.2

The best thing i have learned for sealing threads is hemp.
You have to put a little time into each set of threads,but i have never had a leak when hemp is used.The hemp swells when it gets in contact with fluids.
But a good quality pipe dope will give good results.Teflon tape is often recommend against because if used improperly it can end up plugging small orifices.
Take a picture of the turbo waste gate the PO may have dealt with it by making it manual controlled.
Lift pump is the pump that supplies the injection pump.The OEM one is as good as any on these trucks.
Cooling stack is what the assorted radiators are called.You will have the rad,maybe a AC condenser. Leaves and stuff build up between the two,oil is bad because it attracts stuffs and builds a mat that air cannot flow through.

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The waste gate just looks like a wastegate actuator with nothing attached to it, no hoses or anything... I will try and get a photo but theres not much to see

Quote:

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Originally Posted by Polarisrmk

The waste gate just looks like a wastegate actuator with nothing attached to it, no hoses or anything... I will try and get a photo but theres not much to see

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Does it have a place for a (vacuum) hose? If not, it's probably a '93 version "spring-i- a-can".

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Originally Posted by JohnC

Does it have a place for a (vacuum) hose? If not, it's probably a '93 version "spring-i- a-can".

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yes there is a nipple for a hose but the wastegate actuator is under the turbo not like most of the pictures i have seen. This truck is honestly a mess. I am a Mercedes mechanic and it makes my ocd cringe. I want to get it as close to "stock" as I can then the kid can do whatever upgrades he wants.

If you're not running the stock pump and ECM then there is no reason to add the complexity of a stock wastegate assembly. Does the wastegate just flap in the breeze? If it's the stock turbocharger, I'd contact Kennedy Diesel for a manual wastegate controller.

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Originally Posted by JohnC

If you're not running the stock pump and ECM then there is no reason to add the complexity of a stock wastegate assembly. Does the wastegate just flap in the breeze? If it's the stock turbocharger, I'd contact Kennedy Diesel for a manual wastegate controller.

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I believe its a pressure opened waste gate like a holset turbo has cause the turbo is working. I will hook my vacuum/pressure tester up to it tonight and see what it does. if it is pressure actuated then I will just need to plumb it into the intake and figure out what pressure its set at. Do the 6.5's suffer from high egt with excess boost like om engines, thats really my main concern and over spooling and sending the turbo through the engine.

Best advice i can give you is to replace harmonic balancer and check for any flex plate wobble.

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Originally Posted by 2INSANE

Best advice i can give you is to replace harmonic balancer and check for any flex plate wobble.

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I read about the harmonic balancer I will be sure to do that ... luckily it’s a manual so no flex plate

How does the mechanical injection pump on these compensate fuel for boost ... on Bosch inline pumps I’m used to there is a boost line to a compensation device that increases fuel with boost in simple terms...

Frankly, you have it backwards. Fuel IS boost. More fuel (under load) is more boost. Increasing fuel with more boost is talking to the wrong end of the horse.

The Bosch later model mechanical inline pumps advance timing with increased boost (not fuel volume). The (mechanical) Stanadyne pumps don't do that by an means of feedback, other than throttle position. It has a timing advance cam on the throttle that advances timing with increased input. The end result is similar, but not really significantly different in the real world, and the Stanadyne works effectively for turbo and N/A applications. If you want greater efficiency than either of them, you'll have to move up to an electronic system. Such is where we are today.

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Originally Posted by DmaxMaverick

Frankly, you have it backwards. Fuel IS boost. More fuel (under load) is more boost. Increasing fuel with more boost is talking to the wrong end of the horse.

The Bosch later model mechanical inline pumps advance timing with increased boost (not fuel volume). The (mechanical) Stanadyne pumps don't do that by an means of feedback, other than throttle position. It has a timing advance cam on the throttle that advances timing with increased input. The end result is similar, but not really significantly different in the real world, and the Stanadyne works effectively for turbo and N/A applications. If you want greater efficiency than either of them, you'll have to move up to an electronic system. Such is where we are today.

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yes I understand that was trying to be short. I understand what u are saying
Bosch pumps have the Alda for boost feedback

Just figured out it’s a 6.2 engine with all the 6.5 stuff bolted to it ... did I get screwed?

Using it as just a pickup you will never know the difference.
If you want to work it make sure you install a pyrometer and watch it pulling loads.
Lots of 6.2's got turbo'ed with kits,or replaced broke 6.5's as you have found.

Attachment 5789Here is a photo of my waste gate. Normally open or normally closed? On a second note the compressor wheel doesn’t look good. Are these easy to rebuild turbos? I’ve rebuilt some old air research turbos. Or does anyone have one they want to sell?

Someone added that spring to make it a manual wastegate. Somewhere on this site there is a photo from about 20 years ago of an emergency repair I made when my vacuum pump failed 200 miles from home. It looks amazingly like yours. The spring is pulling it shut. Back pressure forces it open.

[Edit] Found it...
Attachment 5790