Is this an engine crack or paint?

[govt]

I am installing a new exhaust stack on my M109. When I removed everything I noticed what looks like a crack on the bottom part of the engine. This truck runs great with no issues & no leaks around the crack. The mileage states 1700 miles. The pics show the engine as gray in color but its actually green as with most. The first pic is the crack that I am concerned about...the second is the drivers side which is clearly a paint crack. Should I be concerned?

Looking for your expert opinions.
Thanks!

 

[emmado22]

looks like cracking paint to me.

 

[jwaller]

paint crack. if it were a eng crank it would leak like no other when running.

 

[uscgmatt]

I would take a putty knife and rub the crack. If it is just a paint crack the paint will flake off. I would assume it would leak it there were that many cracks.

 

[APM215]

Looks like it to me.
I would be concerned.
clean off the paint and double check

 

[eddiec]

no leaks would lead me to believe it is only the paint.

 

[gusto1]

Take a torch and heat the area up to see if it expands, where you can see a orange line inside the metal. If you can see inside the outside surface of the block, I think you have a crack.

 

[kc5mzd]

I can't tell by the pics - though it looks kind of bad. With no oil leaks I would tend to go with paint. The best way to tell for sure is to hit it with a metal hammer. You should be able to give it a fairly solid hit and the hammer should just bounce off a good block.
If the block is bad...
Well lets just say the hammer will reveal any weakness in the block...

 

[Keith_J]

Is that an overhauled engine? Looks like it, although the engine has a bit of dust. CARC, as applied at the depot level, tends to be thick.

 

[govt]

Is that an overhauled engine? Looks like it, although the engine has a bit of dust. CARC, as applied at the depot level, tends to be thick.

The only info I have on the truck is it's a 71' & was rust proofed in 2004. It doesn't look like it has been used much so overhauled? No clue. No indicators on the truck that it has been.

 

[12345]

Looks like the paint starting to flake to me too. If it was a crack there would most likely be oil residue on the area. You could always go down to your local weld shop and buy a dye penetrant kit of "Spotcheck". It's in 3 spray cans... 1 cleaner, 1 red dye, and 1 developer. Cheap and easy for a non-destructive crack test.

 

[bcombs1952]

With the spider web cracks running vertical also in such a ramdom pattern and no oil residue in the cracks it appears to be cracks in the paint only. That in a non stress area and it is very unlikely to be in the cast iron.

 

[Screamin' Metal]

Yup....can't tell....I'd say if it were cracked.....you'd see oily residue around it....unless its a fresh one. Clean it off with a wire brush mounted in a drill or die grinder....then go to Fastenal and get their mil-spec dye type crack check kits.....

Some freezing of blocks look like that on occassions....froze just enough to mess up good....but I'd check it before assumming the worse.

 

[m16ty]

Take a torch and heat the area up to see if it expands, where you can see a orange line inside the metal. If you can see inside the outside surface of the block, I think you have a crack.

Don't believe I'd do that. If it's not craked it could be after heating it. Anytime you heat cast iron the whole casting needs to be heated the same and allowed to cool slowly. If not there is a chance it can crack when it cools.

I tend to think it's just paint cracking. Get you a putty knife and or a wire brush and do some cleaning. If for some reason the block is cracked I'd run it because it doesn't seem to be causing any problems at this time.

 

[hndrsonj]

Ditto-very bad idea to use torch.

 

[Skip]

Crack or not

Looks like the paint starting to flake to me too. If it was a crack there would most likely be oil residue on the area. You could always go down to your local weld shop and buy a dye penetrant kit of "Spotcheck". It's in 3 spray cans... 1 cleaner, 1 red dye, and 1 developer. Cheap and easy for a non-destructive crack test.

This is the best idea, this will not hurt the engine and will tell you just what you have.

 

[cessnatwin]

looks like bad paint like everyone has said, no oil built up! sand it down and you will know!

 

[Rene M]

I have seen this a thousand times on other Diesel engines. Its called a"ductile paint fracture" Yes, it even has a name. It has caused more panic than any thing you have ever seen.
It happens when the block has an oily area or was not cleaned well before paint was applied. The paint will move away from the block and crack like that. I have to pull engines apart to prove it was not cracked..

The rule is .. no oil or coolant leak? leave it alone. lol

 

[tm america]

take some sand paper sand the area if it is cracked you will see it without paint on there .dont hit it with a hammer if it is a thin part of the casting you will crack it then you will have a crack.my guess is no leak no crack unless they used block sealer if so its holding and i wouldnt worry about it

 

[doghead]

Touch it?