My new to me xj has a hairline crack on the block. Not overheating "yet" But is a crack! Replace with reman? Or take to machine shop?

 

You can see the crack on the outside?

 

I would find a running JY block with over 250000 on it strip it and run it. If a block makes it that long you know it is sound and with all new parts rings, barrings, ext. you will get at least that much more out of it.

 

Sure can. Behind the water pump and below the head. About a inch long

 

Could be a casting flaw from the factory and may never leak if it doesn't leak now.
Just keep an eye on it, and if it does start to leak, plan on getting a good used engine and do not tell the salvage yard its crack so they won't try and charge you a care for a busted block.

 

It is leaking. Very very small amount. I have drove it for more than 2 hours non stop.

 

The sorry part is that I just bought it 1 week ago. And now it needs a motor.

 

If you have noly owned it for a week then I would see what kind of legal action you can take to at least cover some of the price of repair ... I would go talk to the PO first ... maybe the guy will do the right think and at least refund a little bit of cash or help with the repairs .... all depends on if he knew about it and hid it and if you bought it as is.

 

Try JB Weld on it. Can't hurt.

 

What a bummer.

 

Since the engine IS cracked,
Get a jar of water glass.

http://www.ehow.com/how_2300964_use-...eal-blown.html

http://www.wikihow.com/Fix-a-Main-Ga...h-Liquid-Glass

Sodium Silicate.
Your going to have to replace the engine later anyway.
This stuff will seal that crack forever.
I used it one time on a Chevette we got hot and cracked the head, I used a jar of it and drove the car for over a year after that.

Just don't tell them you did that when you decide to replace it and use it for a core.

 

As long as the paper work doesn't say AS IS, if it does than it's all his. Try a good machine shop and see if they can weld it if possiable.

 

See if someone can be weld it ,and yes it can be if they know anything about welding, it's just how hard it is to get to etc, if not than I would get a short block ,a new one not a pile of sheet from a junk yard that you will have to do work to anyhow.good luck

 

Get a new/used engine, do a swap.

 

On the drivers side. Right behind the water pump and below the headers