Overheat coolant - SD25 D21 1987 Nissan

#76

OKAY....
so i pulled the waterpump.... it seems totally fine. it turns a little more freely than the new one i picked up. but it dont spin per se.

the pumps

#77

so......while you were busy, I checked the pump number and it is correct. I put the numbers in at nissan today myself. the current number is 21010-10gy6, and in toronto so 2 days...........but none of that matters and given your situation with the ferry ride, I understand. can't wait to see the pics, I have my own idea of what it might be but am going to keep it to myself and wait........like a school kid. I was loading my creeper into my truck friday and blew out the tail light......on the hunt cannot find ANYTHING so far.........here's hopeing you know where to find one....the Pathfinder will not work of the same year.....and i cannot locate a truck.

#78

so i pulled the head.. with some help from a mechanic. it was easier than i thought it would be. i'm gonna send it in to be inspected. i think ill get everything else checked out. valves etc.

this is my first head job. anything i should now? ask for? ask about?

the head

head gasket

#79

looks like their is alot of carbon tracking beetween two and three, is the gasket failed there?.........are the liners ok? in that location?........cannot tell the pic's are not close enough for me too see..........

#80

redneck.. point and click the photo for closeup

i dropped off the head today. they'll look at it friday. i ordered the head set too.
nissan number 11042 09W27
CAD$225

#81

Lightening up and zooming in, I think that I see two cracks between the valve seats on cyl. No. 3.

#82

The gasket will give you a heads up so to speak of what to expect........is the gasket blown out at that location? is there errosion on the liner from comb.gas going by? are the liners pitted any where? along the stroke that you can see? while the heads are off, really inspect you liners eg, are they polished what kind of cross hatch is left ect...... because i have never had the head off mine i cannot tell you how the gasket seals(i'll bet that is in the book eh, p

), just be carfull cleaning. if they have a fire ring on the top of the liners.....do not use a cookie!!!! you will kill the liners!!clean all by hand!, also look for oil rifleing to the mains and plug them right away too keep stuff from entering the oil system............you are preforming open heart....... cleanlyness IS godlyness!!

#1 KILLER OF MOTORS........ARE PEOPLE BEING DIRTY

got some pics of the block? And thanks for the pt#,i'm sure i'll need it some day

I also located a set of new tail lights for 120 bucks, so they should be here tomorow.

bugger pic keeps givin' be the boot!, i'll keep trying

#83

ummmm... what are liners?

#84

after oil wrote: ummmm... what are liners?

The cylinders in the SD engines ... are dry / pressed into the block. Redneck wants you to inspect the cylinder surface for gouges caused by injested sand, carbon, etc. Expect a few such shallow damage but not THIS MUCH . The "cross-hatch" pattern is usually visible in all but the most worn out of cylinders.

About the cylinder sleeve

"Rifling" refers to the oil delivery gallery located next to #4 cylinder and the two push rod ports. This gallery delivers pulsed/restricted oil through the rear cam journal to the rocker arms.

Cleanliness is paramount.

#85

FWIW, the head on my SD is cracked between each valve seat, but it passed a pressure check so I used it as is. No problems so far. Not to say that yours couldn't be worse, but all three SD heads I have in my possession are cracked there. It may be a problem or may not be. For example every 6.9 diesel I have had apart has had cracks around the induction hardened inlet valve seats with no apparent ill effects.

#86

For old MB diesels, the FSM specs a maximum crack depth permissible

Yes, on a diesel, cracks are sometimes OK . . . and sometimes an indicator of problems. A competent head rebuilder will perform a pressure check before rebuilding.

Subaru EA81 heads (a gasser engine) often have cracks between the valve seats and for some reason that's considered normal by some rebuilders. They also have a habit of cracking far enough to let the coolant out the exhaust port

My Aero 3.0l had one crack near an intake valve seat and the rebuilder drilled it and drove in and peened in a rod -- 85k miles ago.

Galen's liner pics from the link that Philip provided:

#87

I see a crank on the head on the far right cyl- right under the valve seat. Could be my eyes, but it looks like something real. Try wiping some of those carbon deposits off and look closer.

#88

i looked inside the cylinders this morning. there was a bunch of carbon bits or something. i shop vaked it out. wiped it clean and looked closely. i took some photos and uploaded to the server.

i saw on the inside of the liners lots of scratches back and forth. and some up and down....

and a line, i presume the top of the stroke

i covered the whole thing with a clean rag and shut the hood.

#89

heres some photos of the block. like i said, i cleaned them out after the photos.
if the the cyls are numbered 1 to 4 from the front then the photos are 2, 3, and 4 respectively, and 2&3 and 2&3 again but closer.

#90

Could you get a really sharply focused retake of "block_002-c.jpg", 45 degree angle and straight down on the piston top? Curious about the divots. Have you removed and inspected the glow plugs? Tips do break off and exit the exhaust pipe.

Very little cross-hatch is left on the cyls ... normal.

Some verticle gouging from injested debris. Not unusual for an engine with EGR. The crankcase blow-by these gouges allow would not be noticed in an SD25 due to the closed crankcase vent system. In an SD22, it would be due to the open/road draft tube vent system. All engines develop blow-by with age.

Prep and cleanliness pay dividends here. The block surface MUST be SUPER CLEAN and true. 425+ psi cranking compression (to say nothing of cylinder pressure at max combustion) will find a way out at the weakest point. Cooling system is only 15 psi.

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Overheat coolant - SD25 D21 1987 Nissan

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