Oh no ! For 1987 D2 / SD25 trucks cannot be used with compression gauges. Nope. For your kind of truck you may only use crankshaft rhythm while the injection pump is set to OFF. If you hear even crankshaft rhythm ... then your compression is acceptable (your starter and/or battery should be ruined by the time you can tell there is at least ONE cylinder that is either excessive high or too low).
?????
i unplugged all the electrical connections to the IP before testing. i could certainly hear compression, coming out the glowplug holes.
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
Oh no ! For 1987 D2 / SD25 trucks cannot be used with compression gauges. Nope. For your kind of truck you may only use crankshaft rhythm while the injection pump is set to OFF. If you hear even crankshaft rhythm ... then your compression is acceptable (your starter and/or battery should be ruined by the time you can tell there is at least ONE cylinder that is either excessive high or too low).
?????
i unplugged all the electrical connections to the IP before testing. i could certainly hear compression, coming out the glowplug holes.
Oh NO. With the unique "1987 D2/SD25 truck" does not have to have nozzles or glows removed! Didn't you know?
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
well, im carrying on with this before replacing the transmission. im gonna take off the oil pan tomorrow, and the head and maybe see what happens from there.
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
i got the head off.. piece of cake now that ive done it twice i uploaded pics but untill they come ill describe some things i saw.
1. cyls 1 and 3 had considerable caking of black and brown deposits, centred where the small valve is
2. i can see some of the rings when i look down the cyls, i dont remember seeing that before
just a reminder that the head was resurfaced and valves all reground and resealed only a few months ago
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
i found a nissan diesel mechanic!! he works on the 33's on boats. so he's mobile. he'll come by in a couple of days hpefully and take a look. he hopes he can figure out which cyl is screwed and we can replace just that one. because at $175 a pop i would be very screwed to have to replace all 4.
i talked to a machine shop yesterday too. the guy said at 340000km i would be lucky if it were just rings. that if i replaced the rings w/o reboreing i'd be in the same boat again in 6 months, burning oil.
heres some pikkies for y'all, note cyl number etc at bottom left of photo
1
2
2
3
3
4
block
head b4 wiping
head after wiping
3
the last photo shows the head at cyl 3. the brown caking is also on the head at cyl 1. that wasnt there last time i took the head off. for comparisons, if you wish check this post for the head and here for the cylinders
aiight 'nuff said
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
After Oil,
On your pic of cylinder #1 (the one that looks decidedly different than the other 3 and has a glob of antifreeze on it in the pic) It looks as though there are pieces of piston broke loose at the top of the pic. Could be when you cleaned the carbon from the pistons you wedged some carbon in the top ring (always a danger when breaking carbon loose without fully dismantling). Thats what the picture looks like anyway.
Also, note the completely different appearence of that piston top compared to the others. NO injector spray pattern is evident, the flame travel appears to be coming from the piston edges inward (does the truck want to keep running after you shut it off? The oil consumption you talk about would support the rings and piston on that cylinder being toast..... Was that the cylinder with 500 psi compression? A lot of oil could seal that well at cranking speeds.
It will be interesting to hear the verdict from your marine guy, keep us posted.
Looking at the two pics of No. 1, I think that's only carbon. In the other shot, that area is dark, not aluminum-colored.
There is a LOT of carbon for as little time as you've run it, since the head was off last time. To my eyes, it doesn't seem any worse on any one cylinder.
Was there oil pooled in the intake manifold? You said that your vapour separator was new. Did you do the blow-by test that Philip advised (pull oil fill cap off, hold hand over oil fill hole with engine running)?
I'd like a good picture that shows the valve guide seals in place, if you can manage the lighting. That's a tricky camera shot with a run-of-the-mill digital camera. At least look hard at them. Does the SD have both intake and exhaust valve stem seals? I forget.
asavage wrote:SNIP - I'd like a good picture that shows the valve guide seals in place, if you can manage the lighting. That's a tricky camera shot with a run-of-the-mill digital camera. At least look hard at them. Does the SD have both intake and exhaust valve stem seals? I forget.
All 8 valve seals present. You do need to be very careful snapping over the valve guides.
Galen provided this
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
exsimguy1 wrote:It looks as though there are pieces of piston broke loose at the top of the pic. Could be when you cleaned the carbon from the pistons you wedged some carbon in the top ring
those are pieces of carbon that i shop-vacked away.
does the truck want to keep running after you shut it off?
Was that the cylinder with 500 psi compression?
no and no, that cyl was 410 PSI, the lowest of the 4
Was there oil pooled in the intake manifold? You said that your vapour separator was new. Did you do the blow-by test that Philip advised (pull oil fill cap off, hold hand over oil fill hole with engine running)?
i didnt remove the manifold yet, i guess i was hoping i didnt have too. i did do that test and nothing conclusive.
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
the mechanic finally came today. he determined that the rings on piston 1 are shot, the piston moves around a little, and the clean spot that philip pointed out is another clue. the liner is fine, he says, you can still see the cross hatching. he says another clue is this:
so now i start to search for a piston and rings
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
! For 1987 D2 / SD25 trucks cannot be used with compression gauges. Nope. For your kind of truck you may only use crankshaft rhythm while the injection pump is set to OFF. If you hear even crankshaft rhythm ... then your compression is acceptable (your starter and/or battery should be ruined by the time you can tell there is at least ONE cylinder that is either excessive high or too low).
i uploaded pics but untill they come ill describe some things i saw.
