# Possibly the last roundup....



## saudade (Apr 10, 2010)

Well, my 1986.5 D21 base may be finally headed for green pastures and white shores.

My son came home the other night complaining about hard starting, loss of power and a loud banging noise coming from the engine. It sounded pretty bad. Oil looks clean, coolant's a bit "muddy" but not oily.

A compression test showed about 175# on #1&2, with about 25# on #3&4. I could hear a "whooshing" sound when testing #3&4. I hoping it's a head gasket. If more than that, it will be time for us to part.

This has been in our family since day 1. Manufacture date is 12/85 so it's a fairly early unit too. Up until now, it has run great.

I'll pull the head this weekend and see what's going on.


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## rogoman (Dec 16, 2004)

Since cylinders 3 & 4 are adjacent to each other and have about the same compression, it points to a possible blown head gasket. You might want to follow that up with a leak-down test which will pin-point the failed component.


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## smj999smj (Jan 1, 2006)

Could very well be just a head gasket; they weren't uncommon on the NAP-Z engines. The knocking noise when two adjacent cylinders are affected is not uncommon, either. It might not be the end just yet!


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## saudade (Apr 10, 2010)

Well, I'm close.

Got almost everything apart. trying to wedge the timing chain so I don't have to rip the whole front off. Having issues getting the wedge in right. Chain almost slipped off. I made one based on posts in other forums but they don't seem to fit right.

I've started a new thread to see if someone has one.


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## saudade (Apr 10, 2010)

Well, the head's off, gasket surfaces clean. Head and cyl surface flat within .004". one bolt holding the heat shield on the manifold broke off. It's drilled out, tapped and ready.

However, when I scrapped the block I only found 1 locator dowel (rear one). The one in front is gone!! With the wedge blocking the tunnel, I can't see how it would have fallen in. Looking down it, I don't see anything. It's not stuck in the gasket, nor on the ground or the head. Now I need to pull the pan.


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## saudade (Apr 10, 2010)

Well, today's job is pull the oil pan. Since it's 2wd I don't think it will be too bad. I think it's leaking a bit so it's got to go anyway. I just hope I find that dang dowel.


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## saudade (Apr 10, 2010)

Well, the oil pan's off. Not too terrible a job but very dirty. Looks like the factory gasket was "rubber" and not cork so it split off rather easily. 

But, no sign of the dowel. So guess I just replace it and hope for the best. Here's a few pics.


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## saudade (Apr 10, 2010)

Well, I found a dowel at a nearby Nissan dealer. Cost $1.13 so I bought 2. Have no time today and no help to get the head back on. Will pick up the pace tomorrow.


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## saudade (Apr 10, 2010)

The head is ON!!! The cam sprocket is ON!!!! Here's a few pics including the wedge I made. Now I just gotta torque everything down and hope I labeled all those dang vacuum lines correctly.


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## saudade (Apr 10, 2010)

The oil pan and the crossmember are back on. I bolted up the exhaust pipe but still need to so some exhaust work further back. Got most of the grounds, lines and connectors attached. Having some trouble reaching the breather tube under the manifold. 

Still have to lash the valves and check the compression before I button it up. Then add oil, coolant and a whole bunch of hose clamps. But I'm done for today. Hope to finish it Friday.


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## saudade (Apr 10, 2010)

*It Lives!!*

Well, It started up. It's running a bit rough but I still have to mount the rest of the exhaust, connect up a few more vac lines, adjust the valves and add oil and coolant.

I just couldn't wait to see it it ran.


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## saudade (Apr 10, 2010)

It still lives! Had a pair a vac lines crossed. reseated all ignition wires. Now runs smooth! Still need to add coolant and a few exhaust clamps!

Will recheck head bolts after a few heat/cool cycles. But I think I'm done.
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.
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For now.


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