Sooooo first of all it’s a diesel .. specifically a 12 valve 5.9 Cummins out of a 98 dodge 2500 .. I know it’s kinda not a big diesel forum but help me out here.
I blew out the head gasket (I assume so because of the large cloud of white smoke it puffed out and the engine oil in the radiator) I bought the pickup from my buddies last summer and they had blown and replaced the head gasket twice before I bought it. The first time he resurfaced the head the second time he just cleaned it up (it hadn’t been that long). I’m guessing the head is most likely warped but I keep hearing about resurfacing the block. Is this necessary? Is it possible for a engine block to warp out of shape enough to blow out a gasket? Sorry if I’m asking a stupid question.
my next question is since I’m doing head gasket I’m seriously thinking about going with orings or fire rings ... please lern me about them also
tia
MrSmokey said:
Sooooo first of all it’s a diesel .. specifically a 12 valve 5.9 Cummins out of a 98 dodge 2500.
...
I’m guessing the head is most likely warped but I keep hearing about resurfacing the block. Is this necessary? Is it possible for a engine block to warp out of shape enough to blow out a gasket? Sorry if I’m asking a stupid question.
my next question is since I’m doing head gasket I’m seriously thinking about going with orings or fire rings ... please lern me about them also
tia
Yes, you can certainly warp the block, and since the heads have already been decked once, it's likely that's the problem (or the shop didn't do a good job with setup...).
O-rings/fire rings are a good solution to serious high horsepower/boost applications where the cylinder pressure is too high to be contained with normal head gaskets. I don't know enough about your particular engine to know at what point they're necessary, but (painting with a broad brush), if you're not targeting a ton of power and the factory didn't include them, they're not neccessary. Being how your symptom is sucking in water and mixing coolant & oil, I'm guessing you don't have a problem with too much power, but simply a warped block or poorly decked head that's causing you to suck in water on the down stroke and/or pressurize everything and send the coolant into the oil through the head gasket. This wouldn't be helped by an o-ring/fire ring.
So what happens when the engine block warps? That probably doesn’t just effect the top of the block .. what else does it do. Change the cylinder bore shape or what?
MrSmokey said:
So what happens when the engine block warps? That probably doesn’t just effect the top of the block .. what else does it do. Change the cylinder bore shape or what?
Yep. You'd be surprised how much a "solid" cast iron block can flex with just body weight if it's not all bolted together :) That's why machinists have to be careful when using mounting plates that are flat against the bell housing when decking blocks. You can see what we designed I was at Centroid:
Look close as they zoom around the block to the black fixture plate holding the block to the rotary table. There's one solid arm and three that have knurled pads. You slid the solid arm against the block and screw it down, then you just lightly screw the pads out until they just touch the bell housing flange then bolt them down. That way you're not putting any twisting action into the block. When we were developing the block machining process, we found that bolting a cast iron small block Chevy to the "industry standard" fixtures like this:
Would cause the deck surface to warp by more than .004" which was driving us nuts.
The next part of it is for honing, where you need to use a torque plate that simulates having a cylinder head bolted to the block to make sure that the bores are round and true when the head gets bolted to it. They look like this:
Otherwise, you machine it perfectly round but then it's ovalled/warped once the heads are bolted to it. It's not necessary for the boring part of the process, because if your block isn't under torsional load and it's decked properly, then it will be bored close enough that the honing will correct any minor deflection caused by bolting down a head/torque plate.
I don't have a ton of 5.9L experience, but yes, any block can warp. You can check it with a known flat plate of steel or aluminum, or a sheet of glass. Lay it across the deck and use feeler gauges to check it. My guess is that the head is the culprit.
Consult a machine shop, but fire rings are a possible way to solve a warped block if it's not too far out of whack. It can be done with the shortblock still assembled but many shops won't do it that way... liability of shavings getting everywhere. Youtube might turn up some DIY fire ring solutions.
I would check the head and block and see which one is the problem. My guess is that the head was either cut too much leaving a thin deck or it is just a tired/wasted head. That can be crutched with a thicker copper head gasket or a soft steel shim head gasket with a good copper gasket spray, but it won't be a long term solution.
Also, do a search for head studs/bolts. IIRC, there was a recall on either the early factory bolts or an aftermarket bolt/stud that was causing problems. For instance, if there was a recall on ARP studs and yours has ARP studs, it might be as simple as replacing the fasteners.
MIght also be a good idea to find yourself a dial-type torque wrench. As you remove the fasteners, take note of how much torque it takes to break them loose. Might be as simple as a previous job that didn't get torqued correctly, or a head gasket that required retorquing and it didn't get that step.
