cylinder wall pit

Mikey89014

Full Access Member
Joined
Oct 23, 2009
Posts
311
Reaction score
35
Location
Henderson NV
Its a 6.9 with a rain damaged cylinder. Yhe glow plug was loose and rain got in that cylindetr
 

yARIC008

Drives really slow
Joined
Jan 12, 2005
Posts
1,679
Reaction score
83
Location
Orlando, FL
Would defintley want to have that engine sleeved. I wouldn't want to run that engine with that in there. Defintley will increase blow by when the rings pass that location. And of course, could be cavitation. Even if it's not cavitation, if that spot caused any sort of imperfection on the other side of the cylinder it will give cavitation a nucleation site and will become a cavitated hole in the cylinder.
 

typ4

Supporting Member
Supporting Member
Joined
Dec 24, 2005
Posts
9,092
Reaction score
1,372
Location
Newberg,OR
If its a 6.9 itl be fine unless its a very rare circumstance, rings wont care. But if it is cavitation , I will say I told you so.:D
 

idiabuse

Full Access Member
Joined
Oct 15, 2005
Posts
1,242
Reaction score
4
Location
Princeton Fl
I would look into the coolant jacket and you can see the area of the pit from the back side.
The deck surface is thick, you have to see where it starts to get thinner, it looks like you are
safe and it is just a rust hole. Wont hurt anything while running.
Cavitation usually happens lower down middle of the cylinder not toward the top of the cylinder.
Also cavitation is never just one pin hole it is multiple holes in the same location and usually in multiple cylinders.
7.3 at .030 are actually fine. Mine is at .020 and a sonic check showed .225 thickest and .175 thinnest


I would not sweat it and run it.


Javier
 

Mikey89014

Full Access Member
Joined
Oct 23, 2009
Posts
311
Reaction score
35
Location
Henderson NV
Actually i was mistaken. It is on the #2 cylinder on the driver side , and the pit is on the outer edge, about 1 inch down from the deck surface . From the looks of it , it is about .005 deep
 

Wyreth

Certifiable Noob
Joined
Aug 6, 2011
Posts
845
Reaction score
4
Location
Las Vegas, Nv
Personally, I would just bite the bullet and have it sleeved. It's not that horrible money wise, and then you simply don't ever have to wonder, or worry.
 

idiabuse

Full Access Member
Joined
Oct 15, 2005
Posts
1,242
Reaction score
4
Location
Princeton Fl
Personally, I would just bite the bullet and have it sleeved. It's not that horrible money wise, and then you simply don't ever have to wonder, or worry.

LOL! backseat driver! 1 INCH under the deck surface? LOL! a 6.9 to boot! love internet advice! ROFLMAO!


Javier
 

idiabuse

Full Access Member
Joined
Oct 15, 2005
Posts
1,242
Reaction score
4
Location
Princeton Fl
Actually i was mistaken. It is on the #2 cylinder on the driver side , and the pit is on the outer edge, about 1 inch down from the deck surface . From the looks of it , it is about .005 deep

Your perfectly fine dont listen to the flat earthers...



Javier
 

PwrSmoke

Full Access Member
Joined
Jan 2, 2007
Posts
807
Reaction score
22
Location
Northwest Ohio
If it's just a deep pit on the surface, you could be fine other than the possibility of increased blowby. The idea of creating a nucleation site for cavitation, mentioned by yARIC008 above, is a possibility... especially since the block has been bored (or boned ( : < ) 0.030". It would be simple to sonic test the block in that area and if there is plenty of meat, the cavitation thing then becomes a very remote possibility. From the description, if I read it right, it's in that area where cavitation most often occurs but good cooling system maintenance can forestall cavitation. A sonic test might help you sleep better at night. The sure, 100% cure is to sleeve that cylinder but that's another $100, or so added to the bill.

FWIW, if this were me, I'd sleeve it. I think long term and what's going to be happening 100K down the road. I ALWAYS regret most what I DIDN'T do when I had the chance.
 

Hydro-idi

Full Access Member
Joined
Nov 8, 2011
Posts
2,273
Reaction score
359
Location
Lodi, California
We are just trying to help you with your engine situation. Many of us would hate for you to put your engine back together and see something go wrong with it because that will just cost you more time and money. If it were me, I would get it sleeved and not worry about it again. It is better to be on the safe side IMO. It, however, could be fine and run a few 100k like that....who knows. I would take the advice from the members that have been here a while, and not someone's "know it all" opinion/theory that likes to slam everyone else for being wrong because they think they know everything. I like to keep my ears open to learn more things. Seems to be more productive.
 

icanfixall

Official GMM hand model
Joined
Apr 10, 2005
Posts
25,858
Reaction score
672
Location
West coast
Well finally getting the questions answered and seeing its a 6.9 just run it. I don't feel any blowby will happen in that small of an area. Think how fast the piston is traveling going past that area. The piston spped in feet per second is amazing. To be honest the only way to be 100% sure is to sleeve it but running it the way it is now will tel you if money should have been spent when you had the engine apart. But I think you will be fine. The 6.9 cylinders are much thicker than the 7.3 which is know for the cavation issues but any diesel can cavitate too.. Even the big Cats use a coolant to protect the liners. Good luck and try it out.. You may be surprised to find its a great running engine with no problems.
 

jaluhn83

Full Access Member
Joined
May 19, 2012
Posts
1,597
Reaction score
48
Location
Upper Marlboro, MD
Having had water in the bore I think it's just a deep rust pit. Suboptimal, but shouldn't cause any issues.

If it's cavitation you'd have significant coolant leakage into that cylinder and be able to push a pick or something through the spot into the water jacket.

Cavitation is going to show up on the water side - pitting on the cylinder side means it eaten all the way through already so it should be very easy to diagnose.

Not going to be a cavitation nucleation site on the cylinder side of the wall..... might be a bit more likely to cavitate at the corrosponding spot on the water side due to the slightly weaker cylinder wall and more flexing but I doubt it's going to make a difference.

Assuming it's just a pit all you'll get slightly more blowby and oil burning but I doubt it's enough to matter.

Cavitation is a scary monster, but it's also important to really understand what you're dealing with.... that kind of a pit on the water side would very likely be cavitation and cause for serious worry. On the cylinder side on a cylinder that had water and rust issues? Much more likely to just be a rust pit IMHO. Certainly could cause a weak spot and bite you down the road, but no the end of the world either.

BTW, 'hone,' not 'whone' LOL
 

Forum statistics

Threads
91,217
Posts
1,128,487
Members
24,045
Latest member
Ramtough01

Members online

Top