Nissan Titan Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
221 Posts
Discussion Starter #1
Bought my vk for a really good price. Paid 775 shipped from AL to PA. Now the motor was said to need a head gasket. I opened up the motor and tore it down. The head gasket looked fine. There were no cracks or breaks in the gasket. (all the head studs came out fine, except the 2 around cylinder 6 the supposed leak cylinder). Any way a vk head gasket can blow with out actually breaking?:confused::confused:

Looked at the underside of the valves, and none were shiny or clean. They should be shiny from burning coolant. All the valve train is seated in place and has no visual damege.

Looked at cylinder walls for cracks. No cracks in the walls either,

Removed the upper and lower oil pans and the oil looked like chocolate milk in color. The oil drained and flowed green for a second then went to brown.

Is there other things I should be looing at the figure out how coolant is getting into the oil?:confused:

As of now Im thinking possible warped right side head. If any one has input this would be greatly appreaciated. Id like to know what to look for so I only have to take limited parts to the machine shop.
 

·
Premium Member
Joined
·
17,244 Posts
The engine oil cooler runs coolant/oil through a heat exchanger that has been known to leak once in awhile. But if they did compression and leak down tests and said #6 leaked, I would tend to rely on that.

The radiators have a plastic tank that frequently cracks and leaks coolant and can result in overheating. It seems entirely possible to me that overheated aluminum engine/heads could warp.

Preventing Cylinder Head Gasket and Cooling System Failures
 

·
Registered
Joined
·
563 Posts
Just follow the FSM for a headgasket replacement. Check the cylinder deck with a straight edge and the surface where it mounts to the block. I've only seen a handful of blow headgaskets on vks. So if it was overheated then that would make sense.
 

·
Registered
Joined
·
221 Posts
Discussion Starter #5 (Edited)
The engine oil cooler runs coolant/oil through a heat exchanger that has been known to leak once in awhile. But if they did compression and leak down tests and said #6 leaked, I would tend to rely on that.

The radiators have a plastic tank that frequently cracks and leaks coolant and can result in overheating. It seems entirely possible to me that overheated aluminum engine/heads could warp.

Preventing Cylinder Head Gasket and Cooling System Failures

Yeah I will look into the oil cooler setup. I have a large scrape on my upper oil pan where the oil cooler plate sits. Would the oil cooler leak internally or externally at the seals? I would of thought that this would just create an oil leak?..The little rubber (orange) gasket for the plate seems to do nothing. It should be used to seal the plate but I think its shot. Picture below. Also is a cylinder view, this is what all the cylinders looked like.



Just follow the FSM for a headgasket replacement. Check the cylinder deck with a straight edge and the surface where it mounts to the block. I've only seen a handful of blow headgaskets on vks. So if it was overheated then that would make sense.
It was said it overheated. Radiator was also said to be the fix before the "blown head gasket" became the isssue.
 

·
Premium Member
Joined
·
141,094 Posts
Are you going to pull the pistons out?
Overheating will show on the skirts.

Those look like "wet" liners to me.
That means there is a seal at the bottom between the oil and the coolant jackets. If one of those seals went, coolant could get into the oil. It's pretty rare to lose one of those seals, especially on a VK56 because it is highly unlikely that somebody changed a piston liner and bombed the install to a point where the gasket could fail.
Are any of the liners standing "proud" of the block?
 

·
Premium Member
Joined
·
17,244 Posts
Yeah I will look into the oil cooler setup. I have a large scrape on my upper oil pan where the oil cooler plate sits. Would the oil cooler leak internally or externally at the seals? I would of thought that this would just create an oil leak?..The little rubber (orange) gasket for the plate seems to do nothing. It should be used to seal the plate but I think its shot. overheated.


The oil cooler fairly often seems to develop an oil leak, which can frequently be resolved by replacing the $5 O-ring.

However, less frequently, the internal copper heat exchanger within the oil cooler leaks, putting oil into direct communication with coolant.

With the background being failed radiator + overheating, warped head is sounding more likely.
 

·
Registered
Joined
·
221 Posts
Discussion Starter #8
Are you going to pull the pistons out?
Overheating will show on the skirts.

Those look like "wet" liners to me.
That means there is a seal at the bottom between the oil and the coolant jackets. If one of those seals went, coolant could get into the oil. It's pretty rare to lose one of those seals, especially on a VK56 because it is highly unlikely that somebody changed a piston liner and bombed the install to a point where the gasket could fail.
Are any of the liners standing "proud" of the block?
Yes pistons are out. THe cylinder walls look shiny and smooth.
By liners do you mean cylinder wall? And if your asking if there is one sticking up, no they are all the same. The top of the block looks fine. Never wold have known this was the issue If I was never told.



The oil cooler fairly often seems to develop an oil leak, which can frequently be resolved by replacing the $5 O-ring.

However, less frequently, the internal copper heat exchanger within the oil cooler leaks, putting oil into direct communication with coolant.

With the background being failed radiator + overheating, warped head is sounding more likely.
I will be sending the heads and block to the machine shop and have everything pressure checked and decked. But before I do this Id like to find out if there is nothing else that could be wrong. Is it likely I have an internal crack inside the block between a coolant and oil valley?
 

·
Registered
Joined
·
221 Posts
Discussion Starter #9
When I got the motor it had what looks like tap or rain water in 3 cylinders. (all the way to the top on the intake ports of the heads) THere reall wasnt alot of coolant in the cylinders. There was mostly alot of coolant in the oil pans.
 

·
Registered
Joined
·
221 Posts
Discussion Starter #10

[B][I][U]With the background being failed radiator + overheating, warped head is sounding more likely.[/[/U][/I][/B]QUOTE]

I just check this out. THe deck is right on. No warping. THere is no warping that is visible at least to the eye..

Where do I check next?
 

·
Premium Member
Joined
·
141,094 Posts
By liners do you mean cylinder wall
Yes.
What do the piston skirts look like?
 

·
Premium Member
Joined
·
141,094 Posts
Is it likely I have an internal crack inside the block between a coolant and oil valley?
It is possible. I have never had a VK56 apart so I wouldn't know where to look.

Haul the parts down to the machine shop and get their opinion.
 

·
Registered
Joined
·
221 Posts
Discussion Starter #13
It is possible. I have never had a VK56 apart so I wouldn't know where to look.

Haul the parts down to the machine shop and get their opinion.
Yeah Im going to do that. I was able to shine a light into the coolant sleeves around the cylinders and look at them. they dont seem to be broken anywhere. Everything appears to be fine. the block has no cracks in it anywhere so Im going to guess that the head heated up enough to put the slightest warp in it not visibe to the eye and to pass over top the gasket.
 

·
Registered
Joined
·
221 Posts
Discussion Starter #14
I will post a few pics today of my head gasket and the are in question. It is not broken but it the one point seems to be out of place. Unfortnately i have to go back to my friends shop and go dumpster diving to find the gaskets.. gotta love it..
 

·
Registered
Joined
·
221 Posts
Discussion Starter #15 (Edited)
pictures of head gaskets after removed. pictues of gaskets held up right no pressure during holding was applied. pictres as seen are the way it looked after it was removed.



 

·
Premium Member
Joined
·
141,094 Posts
I have never seen a broken sleeve on a motor.
Only severely damaged ones from piston failure or negelct after blowing a head gasket. (got a set on the ground right now out of a 4 banger)
It's pretty rare to have to change them unless something bit the big one.
I highly doubt that happened to a VK56 (young motor family with great service life).

Do you have any history on the lump? Has somebody been in there for some reason before? I have a suspicion that maybe they have and whatever went wrong could be as simple as an incorrectly torqued head install.

What do the piston skirts look like? Not that it matters much, but in this case, most VK56's that failed were changed out with factory new units. If yours got hot and blew a gasket, the skirts might tell us something.

It's not the kill, it's the thrill of the chase.
 

·
Registered
Joined
·
221 Posts
Discussion Starter #17
I have never seen a broken sleeve on a motor.
Only severely damaged ones from piston failure or negelct after blowing a head gasket. (got a set on the ground right now out of a 4 banger)
It's pretty rare to have to change them unless something bit the big one.
I highly doubt that happened to a VK56 (young motor family with great service life).

Do you have any history on the lump? Has somebody been in there for some reason before? I have a suspicion that maybe they have and whatever went wrong could be as simple as an incorrectly torqued head install.

What do the piston skirts look like? Not that it matters much, but in this case, most VK56's that failed were changed out with factory new units. If yours got hot and blew a gasket, the skirts might tell us something.

It's not the kill, it's the thrill of the chase.
I do not know alot of the history. motor has 60k and was never rebuilt. the motor overheated and when i pulle the gaskets off the center of the gasket was raised. the actual cylinder head had no lump. i will have to take it to a machin shop to find out if it has a warp. im thinking it heated up and the gasket became destorted and failed, but didnt break.
 
1 - 17 of 17 Posts
Top