Diesel Place banner

1 - 17 of 17 Posts

·
Registered
1996 GMC 3500 crew dually 6.5 5 speed 4x4
Joined
·
9 Posts
Discussion Starter #1
Hey guys just picked up a 96 3500 crew cab 6.5!
got a bit of a issue I noticed once the truck was warm my oil pressure was dropping away checked the oil and I was 2 liters up and could smell diesel, while checking all my glow plugs noticed 2 were wet I tested them they tested good had listen to the 2 injectors decided to replace them truck started to run smoother I put new 15w40rotella in with Lucus oil stab took the truck to town and back (bout hr run time) and I was up 2 and half litres again, I’m sure
I have a couple more injectors that are bad bit of a miss and white smoke on start up then she has a raw fuel smell at the tail pipe, but I can’t see a couple injectors washing down that much fuel after a 30 to 40 minute drive, what are the chances of a internal leak? Ip drive seal leaking into the timing cover? I know the pumps have a wheeping hole but where else could all this fuel come from?
Thoughts?
ideas?
Should I pull the timing cover and take the gear off?
or should I just pull the pump out have a good look at it?
 

·
Administrator
Joined
·
16,296 Posts
Welcome to DieselPlace
If your oil level rises then you have bigger problems ( as in cracked pistons).
I would pull the heads and inspect those pistons, pull the oil pan and inspect the bottom end and go from there
 
  • Like
Reactions: dieselolds

·
Registered
1996 GMC 3500 crew dually 6.5 5 speed 4x4
Joined
·
9 Posts
Discussion Starter #3
Welcome to DieselPlace
If your oil level rises then you have bigger problems ( as in cracked pistons).
I would pull the heads and inspect those pistons, pull the oil pan and inspect the bottom end and go from there
truck dose not have any blow by, also dose not leak a drop of oil, truck had sat for 4 years before I bought it, really think that it would have a cracked or blow torched piston? Has no symptoms of that, it’s not a dog has some pull and I really rather not be pulling the heads off it and yanking it out if it could be the ip leaking, but I’ll pull glow plugs and scoop and compression test it
 

·
Administrator
Joined
·
16,296 Posts
truck dose not have any blow by, also dose not leak a drop of oil, truck had sat for 4 years before I bought it, really think that it would have a cracked or blow torched piston? Has no symptoms of that, it’s not a dog has some pull and I really rather not be pulling the heads off it and yanking it out if it could be the ip leaking, but I’ll pull glow plugs and scoop and compression test it
The IP does not ( pass thru) into the motor. The IP sits on top of the motor independently, so a leaking IP feeding the crankcase is out.
A combination of worn piston rings and leaking Injectors can wash fuel down into the crankcase.
2 liters of additional oil with a diesel smell is not good and tells me you have internal issues.
I would at a minimum, pull injectors and throw an inspection cam down in there to inspect
 

·
Registered
1996 GMC 3500 crew dually 6.5 5 speed 4x4
Joined
·
9 Posts
Discussion Starter #5
The IP does not ( pass thru) into the motor. The IP sits on top of the motor independently, so a leaking IP feeding the crankcase is out.
A combination of worn piston rings and leaking Injectors can wash fuel down into the crankcase.
2 liters of additional oil with a diesel smell is not good and tells me you have internal issues.
I would at a minimum, pull injectors and throw an inspection cam down in there to inspect
I know it’s right in the intake valley and no fuel lines or fuelsystem is internal, but the up dose mate to a timing gear in the timing cover witch has a seal on the pump drive, I know there’s a weeping hole there too, I only came across a couple mentions of 6.5’s and 6.2’s haveing a pump failure resulting omg fuel leaking into timeing cover seems really unbelievable but with the gains in seeing with no other signs other then a a couple injectors that are loud truck isn’t smokeing when it’s warm not missin,i will be scoping the cylinders for sure and ruing a compression test on it, I appreciate the advice and input too, I’ve had tons these trucks plus Cummins and Dmaxs so I am quite puzzled of the massive internal fuel leak on a 6.5 like iv seen common rails leak pretty bad but not that bad, I’m feeling it’s that dam ip seal but never know right haha time to get greasy and pull this pig apart
 

·
Administrator
Joined
·
16,296 Posts
I know it’s right in the intake valley and no fuel lines or fuelsystem is internal, but the up dose mate to a timing gear in the timing cover witch has a seal on the pump drive, I know there’s a weeping hole there too, I only came across a couple mentions of 6.5’s and 6.2’s haveing a pump failure resulting omg fuel leaking into timeing cover seems really unbelievable but with the gains in seeing with no other signs other then a a couple injectors that are loud truck isn’t smokeing when it’s warm not missin,i will be scoping the cylinders for sure and ruing a compression test on it, I appreciate the advice and input too, I’ve had tons these trucks plus Cummins and Dmaxs so I am quite puzzled of the massive internal fuel leak on a 6.5 like iv seen common rails leak pretty bad but not that bad, I’m feeling it’s that dam ip seal but never know right haha time to get greasy and pull this pig apart
Be sure to keep us up to date on what you find

(y)
 

·
Administrator
Joined
·
16,296 Posts

·
Registered
1996 GMC 3500 crew dually 6.5 5 speed 4x4
Joined
·
9 Posts
Discussion Starter #9
Well that’s the culprit shoulda seen the fuel shot out of the front seal when I pressured the pump! Now to rebuild or get new!
635584
635585
 

·
Administrator
Joined
·
16,296 Posts
Well that’s the culprit shoulda seen the fuel shot out of the front seal when I pressured the pump! Now to rebuild or get new!
Nice find.. Rebuilding it yourself would be outta the question unless you have the specialty tools and shims.
I would recommend taking it to an Authorized Stanadyne shop or find a quality replacement.
 

·
Registered
1996 GMC 3500 crew dually 6.5 5 speed 4x4
Joined
·
9 Posts
Discussion Starter #12
And what kinda turbos interchange on these things now I just used stock with a manual waste gate last 6.5 I had I hate that stupid vac pump lol
 

·
Administrator
Joined
·
16,296 Posts
Any aftermarket pumps you would recommend?
With you being in Canada it's not going to come in cheap..
Closest recommendation I could offer would be Kennedy Diesel In Wisconsin, Leroy Diesel in Texas, or Badger Diesel in Wisconsin
Or you can get one through RockAuto.
 

·
Administrator
Joined
·
16,296 Posts
And what kinda turbos interchange on these things now I just used stock with a manual waste gate last 6.5 I had I hate that stupid vac pump lol
The HX40II is a popular upgrade
 

·
Registered
Joined
·
2,659 Posts
I know a source for new db2's direct from stanadyn, pm for details if you go that route, i can save ya some money.
 

·
Registered
Joined
·
24 Posts
Well that’s the culprit shoulda seen the fuel shot out of the front seal when I pressured the pump! Now to rebuild or get new!
View attachment 635584 View attachment 635585
I have rebuilt many of those pumps as I used to work at a pump shop. It's easy to replace the frt seal without having to tear down the pump. Remove the center bolt of the drive then remove the drive hub. The seal is right there. Pop it out and install new one. Use lube one seal and drive hub when reinstalling hub.
 

·
Ronald Reagan fan
Joined
·
4,190 Posts
Those seals aren’t hard to change as I’ve changed many myself.First though tie back the throttle to full position before you pull the shaft out.Theres a brittle alloy washer inside the pump that can break if it drops out of center when the shaft is reinserted but it’s not a hard job.

Its common sometimes for the two forward seals toward the pump to roll over when you slide the shaft in but go easy on it and you’ll be good.

Sorry just realized this is a 96 truck with DS4?.....the information I provided above is for a DB2 pump.
 
1 - 17 of 17 Posts
Top