Engine/Transmission (1994 - 1998) i need some advise

[speeddemon84]

hi i have a 94 12 valve with 210,000 miles and i just blew a head gasket. i figured if i was going to tear the engine i might as well do some upgrades and maintenance while im at it. my truck had some work done by the previous owner but i am not sure of what was done. i am not an expert on diesels so i was wondering if you guys has some tips and tricks or just good advise on what i should do, any help would be appreciated.

 

[snappy]

Good opportunity to change the supply and return (fuel) lines, set injection pump timing. You could have a valve job done and have the head planned, if required. If budget allows, some port work on head and a camshaft change.

 

[fest3er]

• If any of the hard fuel lines by the firewall, filter and pre-screener show significant rust, replace them. All of them.
• If rubber fuel lines 'on' the engine show signs of age, replace them.
• Fix the killer dowel pin.
• Front and rear main seals.
• If the crank dampener shows signs of looseness, replace it.
• If the exhaust manifold shows signs that it has shrunk enough to threaten breaking or has already broken, replace it.
• If there's any sign of leakage around the valve cover gaskets, replace all six.
• If the fan clutch seems worn (or you never hear the fan, even when the engine is very hot), replace the fan clutch.
• If there's leakage around the P/S pump and vacuum pump, rebuild or reseal them.
• If there's any sign of oil pan leakage, fix/replace/reseal it.
• While the head is off, if any piston or cylinder wall looks worse for the wear, plan to repair such.
• If the belt tensioner seems worn, replace it.

Of course, when in doubt, takes pics and post them on TDR with your questions. Someone will steer you right.

 

[LVJUNIOR]

I would think long and hard about your future plans for horsepower increase. whatever number you come up with add 20% because you will always want more. If you determine there may be a turbo and some fueling in the future, now would be a good time to o-ring the heads and put studs in

 

[speeddemon84]

i didn't think about the fuel lines. i was wondering if i needed or should expect to have the bottom end rebuilt. it ran fine but i noticed smoke from the heads so figured i blew a head gasket. i was planning on putting head studs in and getting a valve job with stiffer springs. i wanted to buy a bd exhaust manifold, and thought about a fluidamper balancer. i dont know what would be the best bang for the buck. i do know a lil work had been done to it. i bought it from a kid that wanted to do truck pulls but got kicked out of his parents before he could. so i think the injector nozzles and a lil turbo work, i make 32 psi now. all the parts look sweet but i only have about 3500 to play with.

 

[snappy]

Unless that truck has been really abused, it should not need the bottom end rebuilt. An oil sample might not be a bad idea. What is wrong with the head? Where is the smoke (exhaust?) coming from? Any oil in the antifreeze? Is this a manual or automatic?

 

[speeddemon84]

the smoke was from the back of the head burning off of the exhaust. and no antifreeze leaking into anything, the oil is not milky. and it is an automatic. i have not been to bad on her but i do get a lead foot everyonce in a while. so like fest3er suggested, ill look at the pistons when i have the head off and if they appear fine i will just leave it and worry about the top end and save money for goodies.

 

[snappy]

Is the exhaust leaking from a rear exhaust manifold gasket? What you are describing is not a typical blown headgasket.

 

[Vaughn MacKenzie]

At 200K a valve job would definitely be a good idea, and plan on planing the head since 12-valve heads always warp. . . usually need to take about . 005" or a little more off to make it perfectly flat again. Be sure to get a Cummins head gasket, never Fel-Pro.

 

[speeddemon84]

well the coolant is leaking onto the manifold and buring up, thats why i saw the smoke coming off of it.

 

[hsmith]

From the heater hose maybe"????

 

[kcv67]

Tappet cover gasket, you have to take the fuel pump off so you are half way there when you take the head off because you have all the injector lines off already.



Casey

 

[snappy]

well the coolant is leaking onto the manifold and buring up, thats why i saw the smoke coming off of it.

That makes sense. I experienced a similar leak on my '95 at the thermostat. My head was cracked and not useable. Before doing any refreshing on the head, have it pressure tested or magnifluxed. Are you doing you own work?

 

[FParisi]

My '95 started leaking a little coolant by the thermostat at 220,000mi. I had the head gasket replaced but my mechanic said no need for doing the valves or planing the head even. It was dyno'd at 293hp at about 130,000mi.

As said, make sure it is really the head gasket.

 

[dansdodge]

I thought Head gasket problems were uncommon on these engines. Am I wrong?

 

[FParisi]

My understanding is that there is a narrow, weak spot by the thermostat. I hadn't heard about a place at the back.