Engine/Transmission (1994 - 1998) Headgasket issues 3rd one in 2 Weeks!

[JoshPeters]

OK guys.....

I'm trying to figure this one out.



I'm on my 3rd headgasket in 2 weeks! The head checks for straightness. The block is straight too. The "worst" spot that I can find is . 0015. After talking to a machine shop... they wouldn't recommend decking the block for that small ammount.



The first headgasket went Combustion to coolant. Enough to blow the lower hose off. Replaced the headbolts at this time.



The Second one went oil to coolant. Checked the head bolts with the Cummins spec go-no go guage. All passed with flying colors.



This one went coolant to the outside world.



The only suggestion that the Machine shop had was maybe the deck surfaces were TO smooth. Rough them up with some sand paper and use studs this time not bolts.



I'm getting tired of pulling the head off this thing. (although I am getting good at it. Just over an hour with no air tools) Both the gaskets only went about 275miles before failing.



This time I think I'm gonna use a . 020 over gasket and Fire Rings with studs.



Josh

 

[1dslram]

Josh:



"O" rings are recommended for street engines, they are more forgiving. But Fire Rings are better at 100# + boost. Your problem sounds like it is related either the bolts or the tightening. With new bolts the short bolts DON'T get the extra 90*. With studs follow what the manufacturer recommends. Good luck I hope every thing works out this time, once is enough three is way too many.

Bruce

 

[PUMPERDUDE]

Are you mopping out all the bolt holes with Q-tips as suggested by Joe D. ? If you dont get them sqeaky clean ,oil or coolant could be squeezed out the holes when you're tightening it down preventing a good seal... Good luck with the next one.

 

[Bandit1]

it is easier and cheaper to replace a head with orings than a block if the firerings arent done correctly. plus there is very little success with firerings with 12mm studs. if you do fire rings the only way to get them to work is with the 14mm studs, if not there is not enough crush on the rings from the small studs. word of advise, do it right do it once.

 

[Joseph Donnelly]

Can't get it too clean or too smooth. After you are sure the surfaces are clean, go over them again with a razor blade scraper, then lacquer thinner. Mop out all the holes as noted above. torque in correct sequence 40-70-100-120-120 ft lb.

 

[JoshPeters]

120? I tried that the first time with BRAND NEW bolts from Cummins... . Result... I felt it start to break... so I stopped. Pulled that bolt... sure enough it was seperating at the threads. I reinstalled the old non-streached bolt.



I cleaned and blew all the holes out last time. I will be sure to do so again this time. I may stud and O-ring this time. Firerings sound good, but till you can get the proper torque they may not hold.



If nothing else I am going to reclean everything, get new bolts and a gasket and try again.



Thanx again,

Josh

 

[chrleb1]

sometimes people recommend a little tiny bit of thread lubricant when installing the bolts. With out the lubricant you can get a false torque reading. What happend is that the threads will start to create a lot of friction and it requires more torque to get the downward force. When you get torque specs from a book or whatever, those specs have been converted to get a downward force. So as i was saying, if your torque reading are actually lower than what you reading, then your downward force will be lower too. Dirty threads will create more friction also.

 

[ata]

Get a Thread Chase Tap and clean the holes out right. That way you will get uniform Torque on all the bolts.

 

[Joseph Donnelly]

I clean and oil the head bolts, then let them drain onto a cloth. Be sure to oil the shouldres too. The first failure might have been boost related. The failures of the replacement gaskets weren't, because combustion wasn't involved. A good head bolt will quickly come up to 115 at least. That is enough torque. Fire rings etc. won't help seal oil and water leaks. Only correct assembly and flat, very smooth surfaces will. We are assuming you are using the very high quality genuine Cummins gaskets, 3283335 (std), -37 (. 010 thicker) or -39 (. 020" thcker).

 

[JoshPeters]

I am using Genuine expensive Cummins gaskets. The last time I used compressed air to clean out the bolt holes as well as running a small screwdriver with a cloth into each hole till it came out clean. I used a small ammount of spray lube on each bolt and wiped it off with a clean cloth as well as running a tap through each to me totally sure it is good and clean. This time I will try engine oil, new bolts and 115lbs torque on all bolts.



Thanks again guys... . any other ideas are welcome...



Josh

 

[Jeff H]

Is there a possibility there may be a crack some where inside of the head? Not visible by eye.

If you ran hot. The heads will be much hotter. The heads are the highest point of the engine. When your coolant drops. Your heads could have run dry. Getting extremely hot. Your temp gauge may only read 220. But actuall temp in the head may be way higher.

May be best to have your cylinder head checked out.

Also wander if it is possible for a crack to only be visible only when the head is heated up at normal operating temps?

Rememer if you get coolant in the oil. It will also be in your injection pump. You will need to get it out asap.

 

[TrqMonster]

it is easier and cheaper to replace a head with orings than a block if the firerings arent done correctly. plus there is very little success with firerings with 12mm studs. if you do fire rings the only way to get them to work is with the 14mm studs, if not there is not enough crush on the rings from the small studs. word of advise, do it right do it once.

I just had my truck fire-ringed with 12mm studs at Scheids. I really dont think that they would install that on my truck if they didnt think that it would be suffeicient as they would have to fix if it didnt work. You are the first person that I have seen that has said this combo wont work. I was wondering if you have any examples of failure with this setup as now I am concerned.

 

[Bandit1]

there is some luck with the 12mm studs, more and more people that do fire rings just have better luck with the 14mm studs because of the extra clamping force that is needed to crush those rings. also majority of the fire ring jobs are with the motor pulled and everythign easy to get to. i hope that you have good luck with your setup, if scheids did the job i am sure it is a good one, dont worry until there is something to worry about.

 

[Vaughn MacKenzie]

Josh, I used synthetic gear lube on my head bolts and shoulders, and let them drain like Joe D says to make sure it doesn't fun down and fill the space at the ends when torquing them down. I also torqued the long bolts 5ft/lbs more and the short ones 5lbs less to compensate for shaft twist, but I'm not sure if this would be recommended.



Vaughn

 

[JoshPeters]

There has not been Coolant in the oil. Just oil in the coolant. The first time it blew it got what I would call warm. It got to the top of the "normal" range... but not into the red.



I have checked it over and over and over for cracks. The local machine shop doesn't have a big enough unit to check it for cracks. Chris (the dood at the machine shop) and I looked it over VERY closely. By looking at the headgasket it appears as though it was not clamped tight enough. When I took it appart none of the bolts were abnormally loose or tight. This time I plan on going through an entire box of Q-tips, use a good clean tap, new Cummins bolts and a new Cummins headgasket.



If it blows again I have come to this conclusion: Time to find a beater car. Then pull the engine, deck the head, deck the block. Get the bottom end balanced and blue printed. Send the injection pump to Haisleys or Shieds. Have them CRANK up the fuel and put in one of their 5,000rpm GSK's. Reassemble with Fire rings, 14mm studs, and Twin turbos. Then attempt to blow the headgasket. At that rate I might have my truck back in time for Muncie.



Josh

 

[PUMPERDUDE]

Might be worth checking the oil cooler... . I like that bombing spirit you got man Oo. Let her rip.

 

[JoshPeters]

Might be worth checking the oil cooler... . I like that bombing spirit you got man Oo. Let her rip.

Thanx Man! I just hope my pocket book can handle it!

:{



Here's a pic of the last one that blew... When it blew it blew coolant to the outside world..... atmosphere if you will. SO bad it was hissing at me.



It is from the coolant passage to the combustion chamber sealing ring, then towards the bolt hole where it escaped to out.



Josh