Hey guys. I have an 86 420ci (6.9) w/ banks sidewinder and 87k miles (so i'm told). Had it for about a year. I am tearing it down and have come up with a few problems and questions for when I put it back together. I am trying to tear down the top end (for many reasons.)

The first thing I meant to do was replace the glow plugs. Most of them are dead (don't ask me how) so I ordered 8 new motorcraft/beru plugs. I had enough time to replace 1 of them between jobs the other day. The next day as I went to replace the rest of them, I first pulled that one out to see how it looked, because the one I pulled was coated in oil (which brought me one step further in figuring out why I have so much blow-by and some idle/accel/cruise smoke) and found that the d@mn tip had broken off the new beru plug already! I never heard it rattle, so I'm hoping it's either stuck in a bed of oil in the prechamber or it had gotten blown out quickly. Thus I am removing the intake manifold/heads to find it and to see how the cylinders/pistons/rings etc look. Why would the tip have broken already?! I got the correct tips for my truck, the zd1a. did I somehow turn it in too far? could it have overheated being the only good tip in the block? (I never had it on for more than 8-10 seconds at a time)

I can't get the turbo out! I have disconnected all the pipes except the y-pipe, decided to leave that one on and wrestle it out because I can't seem to reach to all the bolts that connect it to the turbo, and I snapped the one I did try to turn. The y-pipe does not have quite enough clearance to make it off the studs from the passenger side exhaust manifold, it hits the down pipe and the tranny dipstick tube. I can't get the down pipe separated from the rest of the exhaust, stuck good even after hours of penetrating oil & wood block/hammer pounding, cold chisel, & pipe bending. I can't get the dip tube out cause it hits the y-pipe and doesn't have enough clearance . My next idea is to unbolt the exhaust manifold so I can move it out of the y-pipe and then wrestle the turbo out, but there is not much clearance to get to the bolts on the passenger side. Or cut the downpipe as a last resort.

I want the turbo out because I want to get it inspected. I don't think it's spinning freely enough, only for about a second and it stops. The blades also look a little worn, maybe looks like some heat spots on some of the edges. Anybody ever had a turbo rebuilt? How cost intensive is that?

I've also found that the pipe on the exit of the turbo is only 2.5" all the way back to the muffler. After which it is 4". Go figure. How hard would it be to upgrade to a 3" or 3.5" turbo-back? would I need a new turbo with a bigger exit flange? Should the exhaust headers be replaced too? If I end up cutting the downpipe I will be converting to a stack for sure.

Also when I am removing the intake etc. is it necessary to remove the injector pump? I may have to anyway but I am trying not to, I am having a hard time unbolting the bottom two fuel lines.

Any other thought/tips/suggestions?? Thanks a lot in advance. I always get great advice on here whether I ask a question or am searching the forums. This site has been a truck saver for me many times in the past.

 

You can not get the turbo up pipe and Y out of the truck with the engine installed, even if you had a 2" body lift installed.
The only way to get it out is seperate the up pipe, but then most people have a hard time getting it sealed again.

I know you are not going to believe this, but it is faster and easier to pull the engine.

Not counting machine shop time, if we both started that job at the same time I will drive away about 10 hours before you will.

My first steps will be remove the hood, batteries, radiator, grill and radiator support.
Drain the oil, remove the oil filter.
Remove the cross over pipe.
Unhook the wiring harness, throttle cable and battery cables.
Unhook the fuel supply line and the fuel return line.
Remove the AC compressor, power steering pump, alternator and vacuum pump.
Pull the starter, unbolt the bell housing.
Unbolt the motor mounts.
Block up the transmission.
Now the engine is ready to lift out and I am about 6 hours into the job.

 

sweet. I was almost to that point anyway. So, here it goes pulling my first diesel! Haven't torn down an engine for a while (might as well overhaul since it's out) and haven't ever done so to a diesel. And so begins the big adventure Any tips? Also, I would like to increase performance, mainly in the mpg area. I'm currently getting just over 10mpg by my calc. ideas? Thanks again

 

First tip, the engine is heavy.
So figure 1200 pounds as the weight you have to lift back in once assembled.

A cheap light weight engine hoist is not going to cut it.
Also consider that weight when you look at engine stands.

Overhauling a diesel is about like doing a gasser except tollerances are closer, parts are heavier and bolt torques are higher.

All out power mods will drop MPG.
If you are looking for better MPG, I would leave the base compression alone.
Head studs are a good idea, the 6.9 bolts are a bit weak for a turbo motor.
And the head studs will let you increase the boost some while retaining a safety margin.

 

ha so my old 350 stand won't cut it! didn't think about the head studs but I will pick some up along with a few new ones for the intake, which I found 3 missing from and a couple of replacements that were a bit shorter than the stock bolts. So I increase boost by adjusting the linkage on the wastegate is what I've read. I will probably want a boost gauge as well then. I think I have a tapping on my airbox between the turbo and manifold that should hold one.

How much would cold air intake help? I saw pics of yours in your gallery but it seems like there would be some restriction routing the air to the front of the engine compartment and back.

 

No restriction.
If I try hard I can touch the back of the elbow from the front of the scoop with my arm inside it.

 

This is probably a dumb question but I have swapped a few of these and never pulled the grill or core support are you doing this so you don't have to lift the engine so high or something else.

 

Removing the radiator and crank pulley will give you enough room. That way you won't lose your a/c charge from removing the condensor.

 

My concrete pad is less that perfect for a flat smooth surface here at the house.
My hoist is a tow behind, rather heavy duty, but still not anchored to the ground so it could upset since the engine center of gravity when it clears the radiator support is about the same as the total width of the hoist base.

Add the turbo, twisting the engine sideways I feel the extra safety is well worth the extra time.

I don't move as fast as I used to.

When I use a chain fall hoist, attached to something very solid, I don't mind wrestling the engine in an out.