So I found a crack in the block of my newly rebuilt 3VZE. Sucks to find it after getting everything installed and 300 miles on it. It was definitely not there when we were assembling the block.



A friend said that it may be possible to grind it down a bit and use JB Weld to repair it. Any thoughts?

 

on my old 6.9l deisel I used a crazy block sealer that ran threw the cooling system for 20 min then let it sit overnight. crazy enough it worked but after a year I had to do it again and it worked again! LOL the stuff was in a skinny can with a pop top and was 20 sumthing a can sorry cant be of much help with the name this was 13 years ago

 

Well this is an oil section. Water is 12 psi and oil can be upwards to 60 psi. I broke the rod in the cylinder this is under when I hydro'd the engine. The machinist didn't see anything when he checked the block. Not sure what he did to check it but he charged $20 to do it.

 

if a mechanic had gone over the block and said it was fine, i would take it back to him and show him that it clearly is not fine and see if they can do anything for you

 

I would also take it back and see what they will do for you, if they wont do anything then there is a block sealer you can buy like the one mentioned above also there is a "Stiching " that can also be done to your block but its expensive.

 

is it a 22r or re those things are cake to build and cheap to replace I only used that crap in a can on a gamble cause it was $3000 for a new motor.

 

i may have a long or short block forsale if the price is right.

 

If you don't want to pull it back out & go that route then I would try the JB weld. I used it on an in line 6 engine in a boat & it held for ever. I also used it on an old Datsun p/u on the timing cover where it was cracked. Make sure to grind it down & clean the area with brake clean or something & then put a few coats of JB weld on. After it dries you can sand it & re-paint it. Don't use the JB quick, Use the original stuff.

It really sucks that this happened, Sorry it happened.

 

We use JB weld all the time to fix broken boat blocks and it often works.

Boat blocks break due to frozen water.

I doubt if it will work to contain oil pressure though if the crack is very big.

 

It might be able to be welded but the welding is the easy part. Whoever does the welding would be able to make the call .

The work is going to be pulling it all out and apart so it can be welded Then put back in the vehicle . So no matter how you do it you have almost the same work.

 

I think the part I'm crying over is pulling it back out again and buying all new gaskets again. I spent a lot of time being anl retentive about the oil pump, oil pan gasket, rear main, etc... There is no loss in it at this point to try to mend it with JB Weld. The plan riht now is to use a die grinder to dig it out a bit and then spray it with brake clean and then heat it up a bit with the propane torch and hit it with brake clean again. Then apply the JB Weld to the cracks. Worst case scenario is still the same if I do it or not. Looking at picks of the block out of the truck and stripped down I can see the crack is well below the water jacket.

I am sure if the rebuilder magnafluxed the engine he would have seen that damage, so he must have only visually inspected it.

 

Are you sure it is a crack and not just a casting flaw on the block??

That could be the reason no one said anything . if it is a crack it would be weeping oil if it was not spraying out.

 

You know, I forgot the name of the stuff but I'm sure you could search for it on a boat site. They often use a product to fix cracks on boat blocks & they say it's better than JB weld. I remember reading about it on several of the boat forums a while ago. It might be worth a shot. good luck.

 

if you are going to weld it you need a torch with a rosebud tip and i stick welder with probally 1/8" cast iron welding rod and a ball peen hammer. preheat the block with the torch weld it up good and slow the cooling with the torch. While it cools tap the weld repeatedly unitl it gets cool enough to touch with you hands. you only need the torch for the very first part of the cooling process then just keep tapping with the hammer. if you get the welding rod that is machineable the you can grind your weld down and paint it so its like it never happened. Thats what i would do. or just get another block.

 

So here it is all cleaned up. Next step a little grinding.

Good Lord that's a huge picture.

 

Make sure to drill out the ends of the cracks so it doesn't spread.

 

Pretty sure that doesn't apply here since the forces that caused the crack have been repaired. Too late though, I glued it last night. I will start it up today when I get home. Letting it cure completely.

-PCP

 

Ive used that jb stick weld to mend a few different things. Cracks in tranny housings, engine blocks and a few others. Works great when the service truck doesnt have a welder. And ive had it last up to a few months before I could fix it properly, and it looked like it would last way longer if i let it.

 

Sure the rod that punched the hole in the block is no longer there, but thermal expansion and contraction, vibrations etc will slowly spread the crack. Lets hope its slow enough that the crack outlasts the engine.

 

OK that makes sense. At this point I don't have much to lose as it will requires a lot of time to take it back out and strip it down for the repair.