6.5 diesel over full on oil, or other problems

[huntertownsen]

I just got a killer deal on a 6.5 , 95 180 k, im planning on putting another engine i have in it, but here are the sympoms, it was blowing smoke, the owner said, it was losing power, and then died. it would not restart. I checked the oil, and its about 4 " above full, no water in the oil, it seemed kinda gummy. MY thoughts were a leaky injector, but as i said it seemed kinda gummy and thick. I pulled the glow plugs on 6 and 8 and they had oil on them. what are your guys thoughts, it has sat for about 3 years. the truck is mint with brand new 4" stainless exhaust which hasnt even been mounted yet , and new heads about 10k miles ago, i paid about the same amt for the truck as the exhaust would cost. Im not worried about swapping engines, but was wodering if its worth my time to try to get the old one going first
any thoughts are appreciated.

[Robyn]

Hi
Welcome to TDP :D:D:D

The 4 inch of goopy over fill in the pan is likely a coolant leak had allowed antifreeze in.

Water and oil will layer out and separate, but antifreeze mixture and oil mix into a nasty goopy blend.

Where is the coolant level now ????

Injector leaks can allow fuel into the crank case, but the oil would be highly diluted and it would smell of diesel

Very likely the oil is a grey color ????


A lot of unanswered ?????? but it sounds like a screaming deal.

If indeed the oil has coolant in it and has sat for a long time the nasty mix really messes things up.

Glycol and bearings are not a good mix and the bearings on the crank can and will etch badly.


My recommendation is to yank the engine out and do a complete autopsy on it and find out what is wrong.


A blown head gasket can cause the smoking you spoke of.

Also a crack in the mainline can cause a serious coolant surge into the pan, and the resultant huge overfill can cause a situation where there is so much liquid in the pan that the crank starts turning it into a frothy fog that gets blown over the crankcase vent system and into Turbo inlet and into the intake.

A mixture of oil and coolant that is heavily saturated with antifreeze will not burn well and could explain the huge smoke show and the thing dying.


Get it out and apart and see what you have.

Sounds like a lot of cleaning is gonna be in order.


The 6.5 has been known to crack the main webs, which can progress up into a cylinder bore until it hits the lower end of the water jacket.


Keep us in the loop and good luck.


Robyn

[huntertownsen]

I have never seen the oil seperate, my thoughts is the diesel fuel gelled in the oil from sitting so long. I have been w/o a 6.5 for multiple years now, i rebuilt my other one, then i got hit, the motor has 500 miles on it. so its no biggy. I have been looking for another truck for years, that was a deal. This was a screaming deal, I will update as i know more. not sure of the block # but i am aware of the cracked webs . the block i have is the best of the castings, i just dont remember which one lol ,too long ago.I am leary of a headgasket failure, but it is possible. the reason is the heads were replaced not too long ago with new ones, a well known local diesel specialist did them, but it is possible
I will keep you guys informed

Glad to be back in a 6.5 and glad to be back on the page thx

[Robyn]

Diesel in the oil will not usually gel and it will smell like diesel.

Also the entire content would be thin.

STICKY goopy oil is an indicator of antifreeze contamination.

Oil and water when mixed will layer out in short order and removing the pan plug would show water first as its drained.

When glycol is in the mix the oil and coolant mix stay together.

My bet is that you have a cracked lower end that allowed a big coolant leak.

Fun fun

[huntertownsen]

Interesting about the glycol, good to know. Like i said no biggy, i have another motor, but i will keep you guys informed on what i find. thx for the reply. Any suggestions on injecotors, going to buy new ones, i see them on ebay from dcp for a decent price, anyone use these before , thx again rob

[DmaxMaverick]

I agree with Robyn.

Diesel fuel is oil. Mix Diesel with engine oil, and they will emulsify into a fluid with a combined viscosity of both in proportion. The mixture will NOT become "gooey", and may not separate for decades or centuries or ever (that's what refineries do in less time).

If your engine oil is thick and gooey, there are only a few possible causes. First, is sabotage/vandalism. There are a number of things that can be added to the oil that may cause it to thicken. This would not be accidental or incidental to operation and/or a failure. Next is simple overuse. Exhausted engine oil, if continued to be used, will thicken as more and more soot and other contaminates become suspended (the oil additive package doing its job). The resultant stuff will usually be very dark (coal black) and thick, but very consistent. No goo, slime or separation. Lastly, glycol contamination, which will appear nearly exactly as you describe. Look at the oil filler cap and plumbing for the vapor condensate. Normally, it will appear as a white/gray foamy slime film or globs. It's no more complicated than that.

[huntertownsen]

Yeah , im believing its glycol, whenever i have seen water in the oil, in the past , it was always a milky looking residue. so, sounds like it needs work. Im hoping the heads are ok, since they have very low mileage and they were new. thx for all the advice. no mater what i got a screaming deal on this truck. paid less for the truck than the brand new ss exhaust would cost. really nice shape interior is near mint, only flaw is where the seat has worn from the person getting in and out, but not bad. the exterior has some scratches but not bad. full matching canopy , nerf bars, brush guard, remote pmd, and heath boost controller. hoping it may have an ecm chip, but thats wishfull thinking lol.

[Robyn]

THIS THREAD IS WORTHLESS WITHOUT PICCY'S :D:D:D

Post some pix of the new prize. ;);)

I just noticed...you are not all that far away from me ...

[JohnC]

whenever i have seen water in the oil, in the past , it was always a milky looking residue.

DexCool, it's not your father's antifreeze...

[huntertownsen]

Thx for the info guys, and i will post pics as soon as i get it home, my trailer is tied up on a job for a few more days, thx again
Glad to be back in a 6.5 and back on this page

[trbankii]

I’m looking at a similar opportunity - current owner says that the head gasket went and he shut it off and got it towed home - 240,000 miles.

What are the chances that it is JUST a head gasket and not more serious issues such as the crack in the mainline that Robyn speaks of? Any things to check out short of tearing it all down?

I’m trying to assess what to offer him and there is a difference between replacing a head gasket and replacing an engine…

[Robyn]

Sadly, once the crankcase is full of glycol and its all mixed up everything is polluted.

The lifters (internal parts) worry me as they are hard to flush the stuff out of.

The glycol and oil mix turns to a gray goooooooooooooooop :eek:

Glycol also attacks the babbitt in the bearings, and left in the engine for any amount of time will do serious damage to all bearings.


Best plan is to get the engine out on a stand and rip it apart.

If there is a good likelihood that a head gasket blew DO NOT CRANK THE ENGINE WITH THE STARTER WITHOUT REMOVING GLOW PLUGS.

A cylinder full of water will lock up and the starter will break off and fall to the ground.

ASK ME HOW I KNOW THIS :rolleyes:

Back some years I lost a gasket in a Burb while it was running...

Got it to the house and then decided I did not like where it was parked.

Tried to restart (Bad plan) the engine came up hard and the starter bolts broke off ... clunk

Luckily the block was unhurt and bolts came right out.

Water does not compress ya know :confused::confused:

The mainline crack/break I had was on an early 506 squirt block with large outer main bolts and large squirt nozzles.

The crack started in the "Clip" (machined nick in the lower cylinder from the squirt passage drilling) and continued into the main web, through the squirt passage and also about 2 inches up into the adjacent cylinder wall until it hit coolant.

The web was cracked completely through side to side.

This type of crack is completely different than the "normal" outer bolt hole issue that has been seen a lot.

These failures were peculiar to the early squirt blocks that had the large diameter squirters and also the stress riser (tooling nick) in the cylinders lower edge.


The only way to assess these sorts of failures is to completely tear the engine down and steam out (pressure wash) the bottom end.

Can't see squat with the rotating assembly in the engine.

Fun fun fun

[trbankii]

Thank you for the input. This is a pre-squirt block, so hopefully just a head gasket. I agree on tearing everything down, just trying to do some due diligence before making an offer.

[Robyn]

Possibly a 599 block

There are some folks who have made the statement that the 599 block was the best blocks made by GM ?????????????

The most common head gasket failure points are at the two front cylinders near the coolant passage in the head where the coolant sits stagnant against the block.

The revised Felpro head gaskets have a stainless steel block off plate at that area to prevent erosion of the cylinder deck which is the cause of the failures.

The gaskets soft core fabric also softens over time in this area and eventually degrades to the point that the stainless steel fire ring can no longer hold compression.

Also if coolant PH has not been maintained properly over time electrolysis can set up in the area and the cast iron deck will etch under the fire ring leaving an actual physical ring etched into the deck.

The loss of iron loosens the area as well until the gasket finally blows out.


Care must be taken to be sure that the deck area is perfectly flat without any perceptible grooves around where the fire ring sits.

If there is a damaged area the only salvation is to get the deck machined.

Factory specs say a maximum of .010" can be cut off to clean the area.

I personally have taken decks on the 6.5 to .012"-.015"

Use the Felpro thicker gasket and things are sweet again.

Be sure to use a steel stamp on the rail above the deck and mark "cut .010" or whatever was cut.

Its tough later for someone to tell if a block has been cut if it was not marked.

If you cut one side its best to do both equally to preserve overall dims in the engine.


Buying a used 6.5 is a crap shoot at best no matter what, simply because of all the hidden gremlins that can lurk within.

At 240k I would consider the heads to be junk, so if you get a good short block you have scored well.

Was the engine used as a tow motor (Hard use) ?????

Good luck

[trbankii]

I don’t think it was run hard. It was supposedly in one family and then passed to a family friend, so the history is known and it was supposedly taken care of.