Burning..or leaking oil?

#2

If you only see a few drops of oil from the truck over night, that is probably coming from the breather (draft) tube. that is the crank case breather. pretty normal. sometime you will notice smoke (blow by) coming up from under the truck.

the tube is held on with 2 of the pan bolts, and one long one that goes through the breather body into the block. there is a seal behind it, that may be leaking some, or the bolt has loosened up.

How many miles on the engine? I this a new purchase, or had it a while?

You could be loosing oil past the valve guides, or the rings and burning it.

Adjust the valves and do a compression check. I would do one cold, and one hot. then squirt in some oil and do a wet check to see how much the compression comes up.
Harbor freight has a Diesel compression set up, gauge and fittings. either through the GP holes or injector holes.

the black smoke is unburned fuel $$$ out the tail pipe. dirty air filter fuel filter or injecting too much fuel for the amount of air. there is the adjustment on the rear of the Injection pump. smokescrew.

How old /miles are on your fuel injectors? this can also be a source of black smoke when an injector doesn`t have an even spray pattern or doesn`t completely shut off and drips fuel.

they should be rebuilt every 100,000 miles. or have them pressure tested by a diesel injection repair shop. or if you have a pop testor you can do it your self. NEVER place a finger in the injector spray patern. Fuel will be injected into your finger,

and amputation is the only cure.

Make sure the rubber intake hose isn`t cracked in the bellows, that can be a source of dirty air being sucked in.

Charlie

#3

I've had it about 2 months...153,000 miles. The black smoke doesn't concern me, just that puff of grey.

Ill have to clean the breather tube up and see if anything changes and look for that seal. There isnt much blow by when i open the oil cap either. There is a slight pool of oil right above the exhaust manisold, probably the valve cover gasket.

We do have a harbor freight here, next time i'm out ill certainly buy one, that should give me an idea if im going to be rebuilding the engine or not.

As far as the injectors go, I'm just going to guess and say that they are original.

#4

With 153K on the engine, it is not ready for a rebuild yet unless the previous owner/s really abused it.

The valves do need to be adjusted every 12K miles. your VC gasket could be leaking. they are long lived from my experience. the 2 bolts on the top of the VC is all that holds the cover down, just make them snug, dont` crank down on them or you could crack the cover.

I have access to a steam cleaner where I use to work and have kept mine pretty clean over the years. yours could really use some TLC. If you have access to one or maybe the local DIY car wash pressure washer. I run it up on ramps and do the under side first, then do the top side and it washes the crap down.

The injection Pump doesn`t like extreme temp changes, so don`t apply the water cold/hot directly on it. I do a few quick swipes across it.

My HF compression Tester is the 19 piece one item 93644. I noticed they have a couple other`s that have less pieces. I actuall bought this last spring for my Mercedes Diesel, and it is still sitting here looking at me

.

Look on e-bay for a FSM, I see them there quite often. type in, Datsun Diesel, Datsun SD-22, Datsun pick-up, Nissan Diesel etc... some of these guys seem to think they are gold plated by their prices. I have seen them as low as $10. I have the 82 that I bought at the dealer back in 82, and over the yrs picked up to 83, & 86 manual. the 83 FSM shows the SD-25 engine.

The Injectors are probably ready for an over haul.

What is that plastic container with the red cap, under the air intake?

Charlie

#5

#6

Here is one I found on E-Bay
http://cgi.ebay.com/ebaymotors/1981-Dat ... Literature

This one seems to be just for the engine. the one I have covers the Diesel as well as the gas engine and every other part and system of the truck.

The Haynes and Chilton manuals are ok, I guess. I prefere the FSM.
FSM= Factory Shop/Service Manual

I like your stacks. are they both hooked up,or Just one? they 3 inch?

For the valve adjustments, "adjustments should be made while engine is hot".

Intake----0.35mm---0.014in
Exhaust--0.35mm---0.014in

Set No. 1 piston to Top Dead Center on compression stroke. Adjust clearances of 1, 2, 3. and 5 valves.

Bring No. 4 piston to Top Dead Center on compression stroke.
Adjust clearances of 4, 6, 7.and 8 valves

If you ever adjusted VW Bug valves, these are similar with the adjusters.

I just came across the FSM down loaded here: http://asavage.dyndns.org/Nissan/displa ... Page=front

Charlie

#7

charmalu wrote:I just came across the FSM down loaded here: http://asavage.dyndns.org/Nissan/displa ... Page=front

Charlie

That's just selected bits I've scanned, not the whole FSM. The FSMs are cheap on eBay; I always recommend that owners get one.

#8

4 inch. They are both hooked up..they guy did a great job on the exhaust work. I use to have stacks on my dodge diesel, but i took them off too because it was loud. Im thinking of taking them off this truck as well and putting a regular exhaust back on with a chrome tip. They are pretty loud, and with me driving thru residential neighborhoods for work, they frown upon a loud vehicle.

#9

Do you have muffler, or running straight? then that would be loud, especially going from 1 1/2in to 4in. really amplify it.

really don`t want to upset the yuppies, might rattle the windows in their Preiuses. i ALWAYS FIGURED THE STACKS ARE pRIUS ELIMINATORS.

That is what ear plugs are for

I was at Harbor freight yesterday, and noticed the Diesel engine compression kit is on sale. think it is $21. they if you can locate a 20% off coupon really helps. see them in the AAA mag, some Hot Rod magazines.

Charlie

#10

I have plenty of HF coupons!

I think this is a muffler...you tell me? Its the only thing i got under there. Ive also thought about keeping the stacks, but replacing that hunk o metal under there. Does a muffler have to be "diesel only"?

#11

Well it does look like a muffler, reminds me of an old Trush muffler i had years ago.

I don`t know what the insides of the original muffler looked like when the trucks were new. My original one, the tail pipe broke off at the rear of the muffler. right at the muffler.
I had a muffler shop replace it with a Glass pack, probably about 1996. Iam due again for another one as the pipe rusted off again just past the muffler. the Glass pack hasn`t really been all that loud, even though it is probably packed with soot. I can get it to rap out some.

I don`t know if there is specific muffler for the Nissan Diesel, IE straight through or one like for a gas engine where the exhaust goes through a mouse maze of passages to create back flow pressure.

Iam on a mercedes fourm also, and have seen the 2 mufflers that are on a 300D turbo engine cut open. both are a straight through flow design. I have read through several threads and discussion about the mufflers.
some are taking off the mufflers and running a straight pipe. some 2 1/2 to 3 in. the turbo does muffle some of the noise, but do get a drone at certain RPM`s.

Now with your Datsun, looks like you have maybe a 1 3/4 to 2 in pipe? then going into a 4 inch stack. that will amplify the sound quite a bit. maybe a longer muffler will help some. you are limited by the space available.

Charlie

#12

XDAC wrote:I've had it about 2 months...153,000 miles. The black smoke doesn't concern me, just that puff of grey.

I would be concerned about the black smoke. My first sd22 was ruined by the previous owner driving it with the control lever set partly into the enriched position. He used a manual cable that wasn't properly set up. A little black smoke now and again won't hurt, but black smoke most of the time will coke the rings and ruin them leading to increased oil consumption.

#13

MERRY CHRISTMAS GREETINGS, Guys!
There's another strong probability on that oil/vapor separator. I just repaired mine - symptoms were similar. I'll test it tomorrow (Christmas day). The factory applied sealant to all seams on separator, including draft-tube connection. Less than 140K miles & it cracked. That crack was perfectly aimed to hit the middle of the manifold with what had to be a tiny stream of oil that appeared as though leaking out the bottom of the intake or a split in the head gasket.
The external mess was almost exactly as in those photos - oil all over it.

Frequent trips to the car wash helped some. When it quit, I borrowed a pressure washer & laid into getting it clean again (new glow in the dark paint on engine).
There was physically no way to see where the oil was leaking until disassembled & clean.
As the rings seized, the resultant highly pressurized crankcase spewed oil out every exit, & fuel flooded the crankcase, cutting fuel mileage in half. Power initially dropped by 1/4, then progressively diminished until a no-start forced committing exploratory surgery.
The good news is it's repaired, so Cmdr. Ron can get to church & Royal Rangers.

The story spreads way out of this thread, so I'll stop here.

#14

charmalu wrote:If you only see a few drops of oil from the truck over night, that is probably coming from the breather (draft) tube. that is the crank case breather. pretty normal. sometime you will notice smoke (blow by) coming up from under the truck.

the tube is held on with 2 of the pan bolts, and one long one that goes through the breather body into the block. there is a seal behind it, that may be leaking some, or the bolt has loosened up.

How many miles on the engine? I this a new purchase, or had it a while?

You could be loosing oil past the valve guides, or the rings and burning it.

Adjust the valves and do a compression check. I would do one cold, and one hot. then squirt in some oil and do a wet check to see how much the compression comes up.
Harbor freight has a Diesel compression set up, gauge and fittings. either through the GP holes or injector holes.

the black smoke is unburned fuel $$$ out the tail pipe. dirty air filter fuel filter or injecting too much fuel for the amount of air. there is the adjustment on the rear of the Injection pump. smokescrew.

How old /miles are on your fuel injectors? this can also be a source of black smoke when an injector doesn`t have an even spray pattern or doesn`t completely shut off and drips fuel.

they should be rebuilt every 100,000 miles. or have them pressure tested by a diesel injection repair shop. or if you have a pop testor you can do it your self. NEVER place a finger in the injector spray patern. Fuel will be injected into your finger, and amputation is the only cure.

Make sure the rubber intake hose isn`t cracked in the bellows, that can be a source of dirty air being sucked in.

Charlie

well, a diesel engine runs on oil, and any oil squirted into the combustion chamber could ignite and destroy your compression gauge.. you never use oil to up the compression on a diesel..

do all compression tests DRY on a diesel engine, unless you actually WANT to see your gauge fly to the moon..

#15

Glegor wrote: well, a diesel engine runs on oil, and any oil squirted into the combustion chamber could ignite and destroy your compression gauge.. you never use oil to up the compression on a diesel..

do all compression tests DRY on a diesel engine, unless you actually WANT to see your gauge fly to the moon..

Using oil to check wet/dry compression is a perfectly safe and valid test on a diesel when done properly. That would be with a COLD engine, just enough oil to wet the rings. and the engine turned over a few times to disperse the oil. The compression tester we have in the shop has a restriction orifice in the adaptor fitting which goes in the injector opening in the head. Never had a cylinder fire yet in over thirty years.

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Burning..or leaking oil?

Burning..or leaking oil?

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