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Rebuilding A 6.5 Diesel First Time Need Help

Don't sweat the 506 block, just don't let your temps go over 210 and you shouldn't have a problem. If you're pulling hard and they are climbing above 210, do the fan clutch mod until it engages before 210. Before these forums and the pro's knowhow, GM stamped the danger zoen at 260 on the gauge. Well, at 260 blocks alraedy toasted... no time to worry. Start worrying at 210 and you'll be fine.

Nice work.

Sure makes things look easy with the fenders and grille and radiators removed.
 
Matt Bachand said:
Don't sweat the 506 block, just don't let your temps go over 210 and you shouldn't have a problem. If you're pulling hard and they are climbing above 210, do the fan clutch mod until it engages before 210. Before these forums and the pro's knowhow, GM stamped the danger zoen at 260 on the gauge. Well, at 260 blocks alraedy toasted... no time to worry. Start worrying at 210 and you'll be fine.

Nice work.

Sure makes things look easy with the fenders and grille and radiators removed.
Click to expand...

Well we got the engine in and running but it kept dieing. I forgot to tighten one hose clamp on the fule line. So got that fixed and it still dies, The lift pump wasent workin so i plugged it directly into the battery and it turned on. Some where in the harness is pinched or ripped. By no means do i mean to offend you Chris but there is wires coming out from everything tangled in a big mess and some just going to no where with open ends! There was one hangin out the the fuse box with nothing on the end, a couple in the cab just chopped off hangin there. Some of ones u saudered for the glow plug mod were fully exposed with no tape! Thats Scary man, Gonna be a good couple days re routing,fixing and hiding harnesses but other then that im suprised how good of condition the interior is in for the amount of kms on it. My other question is I plan on putting electric fans in the truck. I have 2 of them on my duramax and havent had any problems. Do the 6.5s run hotter then the duramaxes?
 
No worries. I am not offended. Some of the issues you are describing were there when I first got the truck and I didn't really put in any time to fix them.

I will try to help you out here - the wire hanging in the fuse box is a power wire (I believe for the GP override, but can't remember off the top of my head). It is bare and was connected to an 'add a fuse' (which I removed and used on another vehicle - you can get them at Canadian Tire). I am not sure about the chopped wires. I never chopped any wires. Previous owner perhaps? Maybe even when the command start was installed?

I always cover my soldered wires either with heatshrink or tape. Perhaps the tape didn't stick properly? Can't tell without seeing it. What wires would have been soldered on that relay anyways? As far as I remember, they were all full lengths and the crimp on ends?

As for the tangled wires - I ran all of my wires to the engine compartment through the hole for the throttle cable - I admit, it was a bit of a disaster, I was going to grab some grommets and drill holes through the firewall and do it right, but running them that way worked for the time being...

I have a hard time believing that the lift pump was bad. I tested it before I had headed out on that day I blew the truck up and it tested just fine. It was a Heath HO pump that was less than a year old.

There are always hidden things with old vehicles....I had to spend quite a few hours and dollars fixing things on that sled you traded me too :D
 
Here is how the GP override worked... http://www.thetruckstop.us/forum/showthread.php?t=5440

As you can see in the pics, the bare wires were tapped into the fused side of those two fuses in the block. Those were later replaced with add-a-fuses for a cleaner finish. I took the add-a-fuses back out for a project on my wife's truck when I blew up the old 6.5....

Not sure what soldered wires you are referring to?
 
I re-read Chad's post. The LP is good.

Chad - the OPS in my engine was a brand new AC Delco unit bought from my local dealership. There are no chinese sensors on that rig....just Delco. You will want to check the wiring harness....like you said, you must have pinched something cause it was working fine before...
 
chrisk1500 said:
No worries. I am not offended. Some of the issues you are describing were there when I first got the truck and I didn't really put in any time to fix them.

I will try to help you out here - the wire hanging in the fuse box is a power wire (I believe for the GP override, but can't remember off the top of my head). It is bare and was connected to an 'add a fuse' (which I removed and used on another vehicle - you can get them at Canadian Tire). I am not sure about the chopped wires. I never chopped any wires. Previous owner perhaps? Maybe even when the command start was installed?

I always cover my soldered wires either with heatshrink or tape. Perhaps the tape didn't stick properly? Can't tell without seeing it. What wires would have been soldered on that relay anyways? As far as I remember, they were all full lengths and the crimp on ends?

As for the tangled wires - I ran all of my wires to the engine compartment through the hole for the throttle cable - I admit, it was a bit of a disaster, I was going to grab some grommets and drill holes through the firewall and do it right, but running them that way worked for the time being...

I have a hard time believing that the lift pump was bad. I tested it before I had headed out on that day I blew the truck up and it tested just fine. It was a Heath HO pump that was less than a year old.

There are always hidden things with old vehicles....I had to spend quite a few hours and dollars fixing things on that sled you traded me too :D
Click to expand...

Haha yep there is always always hidden problems with used trucks,selds,qauds ect. Im not mad at all for these little things, i knew what i was getting myself into when the engine was gone. I was just hoping you wouldent do that to your shiny new duramax! As for the pump it works great:thumbsup:. we plugged it directly into the battery that night and it came to life so like i said must be a pinch or rip down the harness in the frame. But that wire that was hangin from the fuse box? Where does it go to? When i went to start it i flicked up your switch and the glow plug light came on. So is that wire still needed? Oh yeah i will try mail you that choke switch for the sled when i get home from work. Thanks for the help Chris
 
chrisk1500 said:
I re-read Chad's post. The LP is good.

Chad - the OPS in my engine was a brand new AC Delco unit bought from my local dealership. There are no chinese sensors on that rig....just Delco. You will want to check the wiring harness....like you said, you must have pinched something cause it was working fine before...
Click to expand...

What's the OPS? And the saudered wires were from the AC by the fire wall and some on the glow plug harness were fully exposed and some were partly....... so yeah they were just starting to fall off nothin some heat shrink wont fix.
 
No worries on the choke cable - I already bought and installed one from Rec Supply - like $20 compared to $80 from the Polaris dealership.

You are right - I left the two soldered wires on the A/C accumulator pressure switch bare because when I re-charge the A/C system (about twice a year) all I have to do is touch the wires together to jump the clutch. No safety concerns there- the wires are far enough apart that they will never touch on their own - just when I needed them to touch.

The wires on the GP harness that are soldered were taped up. I had a hell of a time keeping the tape to stick to those wires for some reason. I had bought some of that liquid electrical tape that I was going to paint the wires with - you can grab some yourself at Canadian Tire or Princess Auto.

The OPS is the oil pressure switch. Did you plug it in? It is the cylindrical sensor at the rear of the engine valley (may be in the center of the valley on your 506 block). The OPS turns the LP on.

I can't remember off the top of my head what that wire was for. If it was not for the GP override, it was probably for when I was running a water to air intercooler on the truck. It would have provided power to the water pump. It probably is just a dead end wire now that I didn't pull out (lazy huh?)...
 
All i can say is WOW!!!! This truck can sure move i love it! But i have a few issues first is the engine light is on and some pretty bad electrical problems, Im thinking ground's so remember how the lift pump wasent working? We checked the harness along the frame and it was fine. So i just rigged up a power source to get it going. Now the heater doesent work or the wipers and the lights are really ****ed. They work fine when the truck isent running. But when it is the break lights are on all the time and when pressure is applyed to the break the lights turn OFF? and the abs light on my cluster is blinking kinda dim same with the air bag light. Other then that it runs great, was loosing come coolant out of the back of the engine but i think it stopped. Will know for sure tomorrow. As for the engine light i pugged in the scanner that came with the truck and nothing happend? Im not sure how to use them, How do you know if the OB2 port has power running to it? If somone can give me a list of grounds to check for that would be great. I olny found 2 engine ground's they are at the top passenger side. I just know there has to be more then that. Thanks!
 
It sounds like you must have missed a ground wire, or screwed something up during the engine removal. There were absolutely zero electrical problems with the truck.

You have to download the software I mentioned to you on to a laptop. Hook the scanner up to the laptop and run the Scantech program.

There should have been grounds from the frame to the engine (braided one by the starter), from the battery to the engine, from the ECM to the engine (rear passenger side of intake - by the trans dipstick), from the battery to the frame (passenger side battery).
 
chrisk1500 said:
It sounds like you must have missed a ground wire, or screwed something up during the engine removal. There were absolutely zero electrical problems with the truck.

You have to download the software I mentioned to you on to a laptop. Hook the scanner up to the laptop and run the Scantech program.

There should have been grounds from the frame to the engine (braided one by the starter), from the battery to the engine, from the ECM to the engine (rear passenger side of intake - by the trans dipstick), from the battery to the frame (passenger side battery).
Click to expand...

Thank's chris, Can you tell me the site where i download the software?
 
Look up 'engh motors scantech' in google. Download the 'free' program and away you go!
 
Well got the program installed but it wouldent connect to the truck, Said it was intrrupted. I don't think there is power going to it. Gonna change the harness over this week and see if that fixes it. It sure won't pass inspection in this condition. haha
 
For the program just go to tools and setting, and make sure you are on Baud Rate 8192, Interface: Echoing, and try different COM ports (in the settings) until it works. If none of that works switch to a different USB port and try the COM ports again.

This is an OBD1 truck.

Check to make sure you have two grounds near the back of the engine on the passenger side. One originally went to one of the intake bolts and the other on one of the coolant block off plate bolts (which might be your leak).

Problem with the brake lights seem to be common issue, because of grounds somewhere. And I had an issue where they wouldnt come on and the dash lights would also have issues, and I just needed a new headlamp switch, a quality one.
 
Well i changed over the engine harness and it did nothing but make it run a bit rougher and it now idles at 1000rpm. I don't know what to do anymore it's ****ed and on top of that the valve cover gaskets are leaking. Yay i get to take it apart again! But yeah still got no heater, no wipers or cruse control and the break lights are still on. i have checked all fuses inside and out all ground's. Did a visual inspection on the harnesses as well. Tryed plugging the scanner in and got nothing once again. I just don't know anymore i have the inspection for next week and there is no way it will pass like this. If anyone has any idea's that would be great i just can't figure this out it really sucks.............


Executing interface test procedures.

Opening COM-port, COM3... ERROR!

Error opening serial port!
Check your port settings and try again.
 
For the scanner, you have to make sure that your laptop's settings are set for COM 4 IIRC...

You must have cut/pinched a wire somewhere...gonna be frustrating, but you have to trace them one by one...

EDIT - for my laptop, I have my settings in scantech as follows: COM 3, echoing, 8192, english,

I remember some people having issues with the COM port - try changing it around.

If that doesn't work, you can pull the codes from the computer by jumping the A and B pin on the OBD port with a small piece of wire and counting the flashes that the SES light makes. The procedure is outlined well on troublecodes.net
 
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