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Head gasket

In a nutshell, yes, these motors are so badly balanced from the factory it's hard to believe. I have a pristine 93 dually, I don't want a new truck, so I have put a bit into it to update things, and built the motor I wanted, and it took me 4 yrs now and it's not quite done. If you plan to keep your truck build a motor right the first time even if it cost and takes a while to save the money, or cheap out now and plan to do it again down the road. These motors can be made to have lots of power and survive doing it for years.
 
Yes improve a BRAND NEW optimizer.

Obviously if you pull yours apart and look at repairing it- there is a ton to do. Sometimes better to start with fresh metal.

GM pinched pennies on this engine left and right. The basic design is good- correct the issues and you can do much better.
 
Goose57 said:
that is why I recommend tearing down the new mass produced engine. Do mean getting a new Optmizer
and and getting inside to do the improvement?🤔
Click to expand...

If someone won the lottery yes start with a crate motor, if a person has a crack free low mile late model 506 block it can be built and upgraded with P400 heads, forged crank, balanced, new pistons etc and have a new updated motor for slightly more than a crate motor that has no upgrades and will be much more than a crate motor. It all boils down to budget, use, and mostly your expectations of said motor.
 
Twisted Steel Performance said:
If someone won the lottery yes start with a crate motor, if a person has a crack free low mile late model 506 block it can be built and upgraded with P400 heads, forged crank, balanced, new pistons etc and have a new updated motor for slightly more than a crate motor that has no upgrades and will be much more than a crate motor. It all boils down to budget, use, and mostly your expectations of said motor.
Click to expand...
Will L. said:
Yes improve a BRAND NEW optimizer.

Obviously if you pull yours apart and look at repairing it- there is a ton to do. Sometimes better to start with fresh metal.

GM pinched pennies on this engine left and right. The basic design is good- correct the issues and you can do much better.
Click to expand...
 
Gentlemen thank you for all your input. My god there are a lot guys on here that know their 💩. Ever since coming to this group I’ve learned a lot about these motors. Love this forum😎.I’m an old ASE retired wrench monkey. Will, first things first. Your hummer isn’t that ugly. Back to my issue. I don’t even know why Im going to pull the heads off. I drove it several times with the temp gauge going up to the danger level then coming down. Thinking it was air in the lines after flush for a suspected plugged heater core. Then the white smoke came then I knew😩. Chris, my block is probably a 95. 166000 miles on it. It’s probably not the best block to rebuild 💁, one guy here said the p400 blocks aren’t available does that also go for the heads.Sounds like (after digesting everything I read on this forum) the best thing to do is get an Optimizer short block if available if not a long block and have the internals improved ( like Will and Chris suggested) and a new set up IP. and a fluid damper and cooling system upgrades. Or just get a long block from Leroy,s and take a chance. Or after a compression check and yanking the heads off w/ no signs of damage just slap some gaskets on and take a chance. Depends how much I struggle. I am on Medicare you know😀.I know it depends on how much do I spend? My old boss gave me the truck for free after it sat for 2 yrs because he couldn’t fix it. Did spend some getting it painted, still needs rockers. Thanks again gentlemen your a great bunch of guys.
 
Ok,
1. Always diagnose, dont buy parts until you know if there is more time than money.

You started talking new engine, so we jumped in head first on spending all your money to get the greatest thing on earth. - my wife says I’m good at that, I am the only guy to win that argument and here is how I won. I said “your right, and thats how I got you.”
Side lesson for free boys- tell her she is right and she is the best- bad bing bada boom she finds your dream truck (my hummer) and leads you to buy it. Haha

Ok, the white smoke and issues sound like head gasket, cracked head, cracked block, combo of the above. If it’s running- verify. Does the smoke smell like coolant? If so, yup engine comes apart.

166,000 miles means if you did not crack the block cylinder wall of #8 (75% chance) or #6 (20% chance) and the block is ok- you might just need head gaskets and above.

So if ya wanna try saving some cash- smell exhaust and if coolant- shut it off. Remove belt. DO NOT DRAIN COOLANT. Pinch off the upper radiator hose close to the thermostat housing and take the hose off. Remove the thermostat cross over. That will spill about 1 quart of coolant. Start the engine and watch which side starts bubbling.
That is the damaged side, that head needs to come off.

I would say yes a compression test is a good thing to do before tearing down.
If the compression is wild or is low- could be damaged rings from the overheating.
Might be the difference of pull the engine as a whole and tear it apart on the stand. Sure is easier to do it that way than in the truck.

There is the problem with cracking main webs on these engines (often from bad balancers imo) so if the rings are gone you have to disturb the cracked mains and at that point, engine is a gonner. Removing the oil pan is the only way to know that.
But if the mains are cracked and you put on a new balancer- they can sometimes live a long life still- just luck of the draw & how bad it is and how hard you beat it. So most of us believe when it’s cracked to just run it till she explodes in that case.
 
Mine has 293k miles on it and I'm sure the webs are probably cracked. it still runs fine with the mediocre compression and some blow by. mine also has the outer ear on the block where the starter mounts broken, welded, and heli-coiled (by previous owner) my plan is to run it till it dies. then maybe just maybe fix up this 6.2 engine that fell into my lap to go in for however long it will last.

the 6.2 engine I have also has mains cracked. so I don't plan to even try disturbing the crank unless I have to. (pending compression check) I was told it was a running engine when it was pulled and converted the truck over to gas.

BTW is your truck an automatic or manual trans? if manual, you can easily convert it to have a DB2 injector pump and rip out 99% of all the electronics including the PCM! if it's an automatic... well that will set you back some $$ having to get an aftermarket stand alone trans computer.
 
Do like Will says, first do the compression test and report back. a new engine will have 400 PSI. and worn engine like mine will vary between each cylinder, mine is anywhere between 325 and 390 iirc between each cylinders with #8 and #7 being the lowest if I remember correctly.

after that smell the exhaust. if you have antifreeze in the system the exhaust will have a sweet smell, if only water, you won't be able to smell the sweetness. only see smoke unless it's oil or fuel. in the case if oil or fuel you should be able to tell from the rich raw diesel odor and the burning oil smell.

Then do the test Will talks about if determining it's coolant.

pulling the heads will only set you back the cost of new gaskets and head bolts to get it back together. you will more than likely see tiny cracks in-between each valve in the heads. Don't get scared right away if you see that, those are known to crack and a machine shop won't touch them if they are. but those cracks don't mean it's leaking coolant from there but it can. they are known to crack there because that is one of the weak points in the engines. post pics of the heads and the gaskets when and if you get that far. we all can help you determine where coolant was getting in at and if it's worthy of just new gaskets.

If you decide to let the truck sit for a while before tearing into it after finding out coolant is the issue, the one thing you don't want to do is let it sit like that without at least draining all the coolant from the system and running it a tad to burn off all the moisture in the cylinders. deciding to let it sit with that moisture in there, RUST is your worst enemy.
 
Wow guys👍 I’m not alone thanks so much. I feel better attacking this with all your guys help. OK enough of the sissy stuff😪. Boy a lot of good info coming from u guys. My biggest fear is after doing a compression test (cold) and finding the readings pretty even and not finding any signs of damage to the block, cylinder and top of pistons and putting it back together ( maybe a fluid balancer to help with the balance oh wait I’m throwing money before time😀). And then finding out rings where weakened from all the heat. Do you think it makes any difference that I’m not doing the test hot ? Along w/ the white smoke from tailpipe there was a little coolant dripping from the clamp on the crossover pipe. Pretty sure the coolant is in the exhaust ports🤔. No signs of coolant in the oil or oil in the coolant. ( I’m hoping that’s a good sign). I will be doing the compression test wet and dry. Maybe even a leak down test all though it might not be needed. Maybe it is just worth it to slap gaskets and studs on it and take a chance but in the back of my mind I’ll always be wondering 🤔. i don’t mind spending the jack for an Optimizer but all the talk on the web about China knock-offs😆 , and the Optimizer still having flaws. Maybe I just answered my own question. Maybe Ill just call Chris and see about improving on the Optimizer? Maybe if I can find a short block. Whoa I’m getting way head of my self. It’s been sitting outside for about two weeks,I definitely will drain coolant. Pull heater freeze plug. Maybe turn it over and get the coolant out of the cylinders. Because like dbrannon79 said, it will be sitting awhile while working on a backup car to get it to pass inspection. I definitely will report back with pic,s and findings, it’s just going to be awhile. I’m sure you guys still be here Thanks again for letting me ramble guys.
 
Running a compression test cold or hot I don't think makes any difference. especially when looking for a problem. now keep in mind that you do want to do some things before trying to crank it with the compression tester on it. you don't want any chance of it trying to start. unplug the PMD, fuel shut-off solenoid, Do a test crank first making sure it won't fire. then carry on with the compression test.

be cautious pulling the glow plugs out in case they are swollen. mark them with each cylinder you pull them from and take note of the carbon build up on each looking for one that is clean (indication of the problem cylinder)

you can also use a bore scope to take a peak into the cylinders through the glow plug holes and see any other damage if you want to.

Oh BTW. remove the inner fender from the passenger side of the wheel well, that will make easy work getting to the glow plugs on that side along with other things.
 
Hopefully these messages & PMs get to you before something goes wrong.

The oil you would squirt in for the “wet” test becomes the fuel and ignites sending thousands of psi up the hose and gauge exploding in your hand faster than you know whats happening. Here is a quickly found article showing 30,000 psi. Some tests I’ve watched videos of are above that figure by a huge chunk. https://blog.diamondracing.net/how-does-a-diesel-engine-work


There is an advanced way to do a wet test with water, but a hair too much and you will bend a connecting rod. So just not worth it in 99.999% of cases. It is safer being the dummy for new bullet proof vests.

Yes leak down tests are good (and normal) but sometimes not revealing because it might take the heat to expand the metal to allow the leak. Also it may take the incredible pressure mentioned above to shove exhaust gasses through a fine crack into the wrong cylinder or coolant passage. Many people see headgasket that puts exhaust into coolant system and swells the hoses and parts a bit. When it goes catastrophic and shoves the actual explosion into the coolant system- Ive seen interesting and scsry results.

Do the “which side” test before draining the coolant, then yes drain the coolant.
 
And not only disable the injection pump but disable the lift pump too.
Do not take any chances on any of this stuff.
There is also a stitch and lock kit that will repair the cracks between the valves in the head. IIRC that was what it was for.
Please reply back if You got that severe explosion warning from Will L.
@Goose57
 
OMG thanks so much you guy’s probably saved my life!!! I do enjoy this forum I usually check back unless I really busy. i will no do a compression test wet. I repeat No Wet! I planned on the lift pump but I will disable LP and test crank. Probably saved me from a lot of damage. The glow plugs are recently new. I did think of the bore scope idea and I have one👍. I do plan on removing the fender wells. Thanks for the read Will very interesting. I assuming that u do the comp. test through the glow plugs? I’ll have to get an adaptor form tester. Thanks again guys I shutter to think what may have happened. I’m an old gasoline mechanic. New to the diesel.
 
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