Head gasket Oh boy!

[phillips5]

Head gasket. Oh boy here we go again. I put 4 in my 89. that I bought brand new. they all blew between two cylenders. I put 1 in my 90 thet I bought used. It was squerting coolent out the side. Now my 93 auto is seeping coolent out the front by the thermostat housing. Going to try some bar's leak and see if I can get by till spring. Under hood looks more conjested than the other two trucks.

 

[Greenleaf]

I know the early 1st gen engines, industrial as well, made during this time frame have the weaker head gasket/head. I replaced one here at school one year ago (1989 model) Its leaking once again Not certain if it's the head or thermo gasket. Real tough to tell at this location. I pressurized it to 15lbs and will not leak but, drive it into the shop cold and shut her down... ..... I have coolant on the floor.



Try the pressure test. On a hot and cold engine.

Hey, look on the up side, you don't have to tear into a 7. 3 No room at the inn



Scott

 

[JLEONARD]

I also participate in a site that deals with marine diesels. It is fairly common for a Cummins 6bta to leak coolant externally from the head gasket area. They call them "nusiance" leaks, and normally just monitor the coolant level for quite some time... sometimes years, rather than replace the head gasket.

If yours fall into this category then you may be able to get by till spring.

Jay

 

[paccool]

I think that if I ever start having this problem I'll get one of those new heads that piers has. Would be a good excuse to upgrade!



Will the O-rings help with this leak problem? Seems they would.



Stan

 

[Greenleaf]

Ask someone who knows more..... I believe the "O" ring is designed to seal compression.



Scott

 

[BushWakr - RIP]

The O-Ringing is related to holding higher boost pressures. It is not designed to address water leakage issues.

If you are having repeated head gasket failure then I'd really look close at the head and block surfaces.

You may need to have the block and head decked to tolerance. There is no way you should continue to get "bad gaskets" as a reason for coolant leaks.



I have been lucky with my 93... . it has taken and held on to 53 psi boost and as high as 1800*F on a wild dyno run... ok, a couple 'O three times actually... no water leaks, no boost leaks.

You may also need to have both head and block surfaced, new head bolts put in and the latest gasket installed. Once the truck has been run and warmed up, do the re-torque as per manual.



Ooppsss... . that's a 5 RWHP penalty for me... I was thinking of the exhaust manifold... . no retorque on head bolts... sorry guys...



Bob.

 

[paccool]

Thanks for the clarification Pastor. Guess I thought the O-rings would help prevent the head gasket from blowing between cylinders.



Well, I still think that if I have any problems that I will opt for one of the heads that Piers has. Got 180,000 miles on mine and so far no problems. Now, I can assume saying that is like the kiss of death and I'll probably start having problems!



Oh yea, got the new 60 psi boost gauge in over the weekend. Empty, getting on the freeway, saw 33psi boost. Will be pulling the trailer this week so I'll see if that makes a difference.



Stan

 

[Greenleaf]

Pastor, how would one go about decking the block? Do ya have to pull the engine and dismantle it? I'll be pulling a John Deere block this week for the very same reason. Only this guy went one step further..... ran engine with the blown gasket and resulted in coolant seeping into crankcase, resulting in spun bearing, resulting in engine halting unexpectedly



The good news is... . makes me $$$$$$$ for that HX35,,,,,more power, Oooohh Yaahhh



Oh, by the way,never,under any circumstances,brag how well your truck is doing..... sudden failure is eminent



Scott

 

[Paychk]

Not sure what brand of gasket you guys have use but this is a comparison of the Cummins to a Felpro, the Cummins is the top one. Notice the sealing rings on the passages are doubled in certain areas.

 

[Paychk]

Heres another showing the size of the fire rings.

 

[paccool]

Paychk,

They say a picture is worth a thousand words and this is one of those times. Great pictures, good info!



Stan

 

[hdm48]

Paychk hit it right on. Don't even think of useing a felpro gasket. I've seen them blow within 5 minutes of run time.

Use a Cummins gasket only.



And the pastor is right also. You must have a riser or a dip somewhere on the block or head or both. Use a precision stone to work both and look for problem areas. You can work out small ones but it will need to be surfaced if they are too big.

Once a gasket blows and it is ran, compressed high heat gasses will work harden the area and it will no longer hold a gasket. Gotta machine it out.



Dave

 

[bmoeller]

May need to replace the head bolts with the new gasket.

Something I have run into, is that when replacing head gaskets and reuseing the old head bolts, they will leak shortly after. The bolts stretch enough to bottom out in the holes and the head isn't torqued down properly and causing problems. Replaceing the bolts and a new gasket fixed the problem.

 

[Paychk]

I need to give credit to TTammeslehto, these pics are from his web site, he posts in the conversion forum.



You can see the originals on his site, and it is amazing what that guy is doing to his 5. 9B



http://samba.student.oulu.fi/~jpontys/cummins.html

 

[paccool]

Alan, I just went to the site you gave - WOW! He is really doing it right. Wish I had the skills and patience to do porting like that. I'm going to match port the head to the new ATS manifold but it won't look anything like that! I am afraid I'll take off too much so it will just be a gentle port job.



Stan

 

[dpuckett]

bmoeller,

When i did the head gasket in mine this summer (why cant anything big go out in the fall? It was 100 deg when I did it), I got a bolt guage in the kit, and all my HG bolts were at least a 1/2" short of the limit. Point being, use the bolt guage, and you should be ok. Ijust had the CHilton manual, and it said nothing of the torque plus angle- just straight torque. So I went with instructions from here, but, no one mentioned a retorque. it has been 8K since I did it; do I need to do a retorque? Or if it aint broke, dotn fix it? I need to get a new head, anyway (eventually)- has cracks inthe head between the intake valves and injector bore. guy said he'd seen them run on Case tractors with much bigger cracks, and have no problems, so I just ran with it, and have been good thus far, knock on wood (knocking side of own head )



Daniel

 

[OTRPU]

I won't let one leak water again. DOC said it may hold that way for quite awhile. 3 thousand miles later, under load in WV it blowed. Coolant in the cylinders, that's all she wrote. Maybe. . . if I'd shut her down immediately it would have been cheaper to save the old one. Head is cracked at 5 of 6 holes, prolly all 6, just can't see it without an x-ray. I can put in a new engine cheaper than rebuilding the old one. If I ever see evidence of water past the head gasket on outside again I'll replace the head gasket. Lots cheaper than engines. One thing, this way I'll have a lot of spares.



Cheers,

Steve J.

 

[Greenleaf]

I'm cornfused... ... . I do not recall any mention of a re-torque in the Cummins engine manual. Besides,,,,how in the world could you do it?????I do it on the John Deere heads without any gain I might add. But, with the Cummins "torque-turn" method you would be hard pressed to do a re-torque. I mean think about it. You torque to 65lbs ft then turn 90* or what ever the specs are. Now you run the engine a while. Get it good and warn. What;s to do next? You cant turn it another 90*. There is not a final lbs foot spec I am aware of here. What would you "re-torque" to?????? The John Deere is easy,re torque to the final torque of 275lbs ft.



Does anyone get my point, or is it me who is missing something here? Please enlighten... ... ... ... .



Scott

 

[bmoeller]

I haven't ever had to retorque a head yet. If they give range on the torque, I usually use the max, or close to it. Even on Deere engines. No problems from it.



On the engine we did have a problem with (on a Allis-Chalmers 8070), I wasn't the one that installed the head. Don't have a bolt gauge.



When I replaced the head gaskets on my 6. 9L, I replaced the head bolts.

 

[phillips5]

As for retorking the head on the big engines we loosen re lube the washer and retorqe to spec one bolt at a time. Big engines like the 855 cummins or mack .