6.5 bad head. Passenger side.

[DieselAddict]

Hello ppl I'm somewhat a newbie to the 6.5. And I know I have a bad head on my 96 3500 TD. I removed my coolant crossover pipe. Removed my belt. And ran the thing. Bubbles immediately started flowing out of the passenger head. I ain't burning any coolant in the combustion chambers. The thing becomes air locked and there's no heat in the cab. Then I'm guessing the air lock pushes through and the heat comes back on. And the temp drops again. And this is all while leaving the resivour cap lose. So the system doesn't get over pressured. The question is. If I put a barbed brass fitting in where the bleed screw is right now. And run a hose to the over flow outlet on the resivour. And leave the cap lose (not sealed) would last me awhile doing this. Until I can get a new head for this truck. If I can get some feed back on this. That would be great. Thanks guys.


D.A.

[DieselAddict]

Sorry. "Would this last me a while?"

[arveetek]

It could be just a head gasket. If that's the case, you don't want to drive it any longer than necessary. If exhaust gases are being pushed past the head gasket into the coolant chamber, then it can erode the block and/or head, causing even further damage.

No, I would not drive it until you get it repaired.

Casey

[DieselAddict]

Thanks for responding Casey.

Ive been dreading the problem. I done the head gaskets at the end of last summer. The temp stayed steady for awhile but started jumping n dropping after a week or two. And I'm sure it's a head. I know there's surface irregularity on the same side but on the block. It's shaped like a water jacket. And it has a bit of an indent. Which is not normal. I've got a buddy with a 98 suburban 6.5 and he wants 1700 for the motor. It runs clean. No blow by. But I would hate to buy another damaged block. As he doesn't know what it's been thru. As he bought it a few years back. And put a new transfer case in it. He wants 2500 for the whole burb. But I ain't into buying the whole vehicle. But this is my dilemma. I like the 6.5 and don't want any other truck. It's easy to work on. And is a lot better then paying out the rear end for a brand new truck. My wife of course thinks a lot different then I do. But I'm a grease monkey and enjoy the challenges. So I'm in the market for a motor that I can clean up n rebuild for the swap. There's a few around for sale it's just trying for the best one I guess. Spring is around the corner and that's when things start happening for my business and I need my truck. If there's any tips on wut I should be looking for. That would be great. Thanks.


D.A.

[Robyn]

A common thing on these when they get a bunch of miles on them.

Any low spots in the block where the stainless fire ring sits is a deal breaker.

There is only one fix, and that is to tear it out, apart and get the blocks decks cut.

You can safely cut.012" off, and if they don't clean up I have seen them cut to .015"

Felpro makes a .010" thicker gasket.

***** NOTE*****
The newest Felpro gaskets have a stainless steel plate that's part of the fire ring on the front cylinder and this keeps the coolant off the area and helps prevent the etching and ultimate failure.

Always use new bolt kit "ALWAYS" as these are torque to yield and once used and removed are no longer usable.

Running with a leak just eats away the area that's leaking and will make it worse.

Usually the front cyl between the fire ring and the water passage is the place these go away.

The front passage is blocked off and the coolant lays there against the deck of the block and depending on the junk that may be in the water that's been mixed with the antifreeze there can be serious electrolysis action, and therein lies the culprit.

A dark stain around the fire ring is fine, but any groove etched into the block is a no go, and will leak again soon after any new gasket is fitted.

Sorry to toss cold water on the campfire, but these are the hard facts.

DO NOT be led to try COMETIC gaskets, they do not work on a Six and a half diesel. (Been there, done that)

Sadly there are no easy trick fixes.

If the engine is out, the bottom end needs to be checked for cracks in the main webs, and if present, don't waste your $$$$ if the top deck is badly eroded too.

If you find small web cracks, and the deck can clean at .010" then the webs can be repaired with the use of a "LOCK N STITCH" insert in the hole that's cracked.

If the crack is in the register area where the main cap sits into the block, then it's game over.

Good luck.
Keep us in the loop

[DieselAddict]

Ok. This is all really good information. Thanks Robyn.

The pitting on the deck is just forward of #2 cylinder. I've phones the guy at the local machine shop about this and he knew all about it before I had to elaborate any further. As he's a Chevy guy himself. And dealt with a lot of 65's in his days of been in business. The whole deck is clean n shiny. But this one surface irregularity. Which is common.

He told me to take the head off again. Bring it in. He'll resurface it. And told me about a 2 part epoxi mix. That has some sort of metal in it. He believes it's aluminum and said I should pick some of this stuff up. Put it on with a putty stick and remove any bulges with a sanding block after drying. He's done this to his 6.5 when he had one. N never had a problem with it after this. But since then. He has a nice duramax sittin out front of his shop. So I'm guess he's days with the 65 are done. If anyone has done this as well. I'd love to hear about it as well.

Thanks again.

D.A.

[Dvldog8793]

Howdy
Just a flash in my brain housing area, when you said using an epoxy. IMHO...I would not. The reasons that would hold me back are that epoxy has different heat expansion properties than cast and if this was something that worked it would be common practice. Maybe it is common practice and we just don't know about it....:confused:
Did you use new bolts last time?
I would try to get the engine out of the burb asap and then do any work to that one and run it.
Good luck!

[Robyn]

Might work long enough to sell a rig if you're into that type of patch up.

I have been around the 6.2 since they were introduced in 82 and then on to the 6.5

When a head gasket fails due to an eroded block, there is one fix, and only one that works.

As mentioned previously.

If the rig is nice and clean and a keeper, fix it right.


Replacing gaskets, bolts and other supplies plus the knuckle busting is not worth the $$$$$ and effort wasted on anything but a proven fix.

The six and a half has some issues, but if fixed right it will run a long time.

[DieselAddict]

Alright folks. I figured it would be wise to get the other 6.5 rebuild it. And swap out my 6.5 that's in my pickup. Because it is a very clean and has very minimal rust along the lower part of the front doors. It's a crew cab. It only has 180k kms on it. I can get myself outta some pretty deep snow. Just slap we in low. So there's even power to all tires. N the thing just pulls itself right out. I don't see some of these new trucks do that these days. If there stuck. There stuck. I think I have my decision. Thanks for all the info. This is an awesome site. I'm glad I joined. I'll keep you all updated on how it all pans out.



Cheers.



D.A.

[Robyn]

Good luck

;)