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1dumrednek

head gasket again

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my head gasket went again. found a big puddle of oil under the truck and its coming out right in front between the head and the block. i did the head gasket 9 months ago and put ARP studs in and was really hoping it wouldnt go. didnt think it would with only 45psi boost. any ideas on why?

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Did you torque it in small increments ? Did you retorque it ? Did you have the head checked to see if it is flat ? If it lasted that many months could be a retorque issue. Hard to say.

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torqued in small increments, didnt re-torque, didnt have head checked. torqued to 125 ftlbs. theres no oil incoolant and no coolant in oil. just oil on the ground. just seems weird to me that it would leak oil out of there

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torqued in small increments, didnt re-torque, didnt have head checked. torqued to 125 ftlbs. theres no oil incoolant and no coolant in oil. just oil on the ground. just seems weird to me that it would leak oil out of there

Only from what I have read online many say the flatness of the deck is as important as anything for preventing failure

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When you crush a new head gasket and stretch the arp's it is important to retorque. I only say this because yours lasted 9 months. There could be many factors as to why it started to leak. Did you use a factory cummins gasket ? 45 lbs is around the range limit for a factory hg, mostly.

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When you crush a new head gasket and stretch the arp's it is important to retorque. I only say this because yours lasted 9 months. There could be many factors as to why it started to leak. Did you use a factory cummins gasket ? 45 lbs is around the range limit for a factory hg, mostly.

45? I did not know that. I agree w everyone concerning straigtness of the head. Is that where is always leaks? Sorry 1Dum, that would suck!:spend:Not to mention your time & the effort it takes!:broke: Sounds like my luck at times around here too! Can you re-use the new head studs on the rebuild? They are not supposed to stretch at all! Is this your DD. Sorry DUDE, Dave

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Ya I used a gasket right from cummins. First time it leaked coolant into 3 cylinders and I think I just stretched the bolts on that one. This one is oil comin from the front and rear oil galleries. The rest of the gasket appears fine. And as far as I know you can re-use the studs?

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torqued in small increments, didnt re-torque, didnt have head checked. torqued to 125 ftlbs. theres no oil incoolant and no coolant in oil. just oil on the ground. just seems weird to me that it would leak oil out of there

Unless ARP studs are different specs, You should torque in sequence 59ft.lbs then torque in sequence to 77 ft.lbs then recheck in sequence 77 ft.lbs then 1/4 turn (90 degrees) in sequence:2cents: one last thought did you get you gasket from Cummins?

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kinda hard to get that done out here. small town an hour and a half from any city

I know exactly what you mean I got 3 hours from a major city (Boise, ID)... :rolleyes: So like myself I would consider pulling the head back off and having the head taking down to a machine shop in Boise, ID and have it surfaced and check for true flat. Then go back through with a fresh gasket...

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sent the head in to get checked. its slightly warped and cavitated. he figured hed have to take about .005 off it. is that gonna require anything else like thicker gasket or injector washers?

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If it was my head i would use the stock gasket. These diesels love compression. I bet it will run better. If you have the injector down in the hole more it will run better as well. My injectors are 20k deeper in because the injector body was shaved.(long story) Off the line is better than before. 5k off the head is nothing. In fact thats within factory spects if i remember correctly. Did you check the block to see if it is somewhat straight ? Use a razor blade to clean the block try not to get crud in the water/oil passages,if you get crud in the piston just suck it out with a shop vac.

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Just got finished up a couple weeks ago with my HG and had the exact amount milled you are looking at. I went back stock cummins HG with new head bolts and I spent from the Saturday I took it off till the Saturday I took it back cleaning everything up. I cleaned the deck off till it was like new looking then cleaned everything up with the shop vac. Also spent a long while on each stud hole in the block with a tap cleaning them out until it spun freely all the way to the bottom in each hole. Knock on wood all mine is back together and running like a champ with my compression leak all taken care of. Wish you the best of luck on this one and hopefully it takes care of it for you.

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If it was my head i would use the stock gasket. These diesels love compression. I bet it will run better.

How does variable thickness affect compression - someone else mentioned that in another thread but I didn't bite - now I gotta ...... I thought it just sits between the head and block and has multiple passages for bolts,coolant etc ? Never done a head or seen under one hahah

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This is what i have found. Stock trucks or mostly stock trucks love compression. Race trucks not so much only because of massive boost 100 psi plus they add meth/water and or nitrous. Bottle pressure of nitrous is around 1200 psi. So racers lower compression. 14 to 15:1 give or take. It will lower the stress on the rods etc. Lets say your home air compressor can only put out 16 psi. If you fill a small tire with that 16 psi it will work fine because that tire requires just 16 psi. If you try to fill a truck tire with 16 psi the lower pressure will be inadequate because that tire was designed for 80. So you lowered the compression. Will it still work ? Yes. Just not as good.When you lift the head off the block with a 20k head gasket you take away around 1. So our 16:1 is now 15:1. You may say wow thats not much at all. It is on a diesel. Or when you remove material from the piston (fly cut) because of a big camshaft.When you lift the head up 20k you also change the spray pattern. Well, you dont really "change it" so to speak, but you do change the efficency of the design originally intended.I put a 20k hg on a unmachined head. I lost low end power. It started hard in the cold weather and sounded strange when it would run until i built heat in the cylinder. It also poured out white/blue smoke. I did compensate the injector by having 20k removed off the body of the injector so it would have the same spray pattern. However when i sprayed nitrous along with the 60 lbs of boost it ran well.Thats my take on it. The facts may vary with my opinion stated above.My job blows in these lagging economic conditions so i dont spray nitrous at this time. I now have a stock gasket on mine. It runs way better compared to the 20 over hg.

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sent the head in to get checked. its slightly warped and cavitated. he figured hed have to take about .005 off it. is that gonna require anything else like thicker gasket or injector washers?

Just for your own benefit, get a metal straight edge & check the block as well. You should be fine after this one. I know if mine ever goes, I will get the head ckecked just so I wouldn't have to do it again. Thanks for the lesson here! Good Luck, Dave:thumb1:

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This is what i have found. Stock trucks or mostly stock trucks love compression. When you lift the head off the block with a 20k head gasket you take away around 1. So our 16:1 is now 15:1. You may say wow thats not much at all. It is on a diesel. Or when you remove material from the piston (fly cut) because of a big camshaft.

gotchya - thanks for the 101 :thumb1:

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