Add me to the list of block cracked behind #6 with no history of overheating. Factory replacement 4.6 installed under warranty in 2007. 160k on in. Sounds like this may be a new trend.

 

Given how thin the cylinders are on the blocks that were machined poorly, it doesn't surprise me that they are cracking at random.

Engine blocks twist under load, especially cheap factory aluminum blocks. Honestly I'm surprised that you guys that tow with your discos haven't encountered block cracking more frequently than the average driver.

 

I have a Turner short block with the upgraded cam. It is much better than stock. If I could do it again I would do a long block with the gas flowed headers. I had just had my heads redecked, so I did not.

I have gone to an electric fan, K&N filter, and built a different tube for intake and those have helped with power. Doing headers would be great, too, but don't feel like the other upgrades are a waste of time if you do not.

 

Thanks for all the replies. I had thought about getting just the short block, but I'm going all in with the full engine. I'll probably skip the headers for now. I'm replacing the entire cooling system, as I don't know what the high pressure has done to the hoses or radiator. What really sucks is that my Disco was meticulously maintained, never overheated, head gaskets done 30,000 miles ago. I had no sign of this failure. I had never seen an ultraguage move so fast! I didn't have an alarm set, but it wouldn't have mattered. The block failure is what caused the overheat in this case. At least after dropping $9000, I won't have to constantly worry about when the engine will go anymore! I'm really trying to find a silver lining here...

 

That's a decent silver lining, just sorry you have to look for it. I'm sure you'll do a replacement thread for all of us to drool over.

 

I hate stories like this! Sorry to hear the news and I am sure captures all of our attention. Especially the numbers that you posted with the 180F. My 03' has 62k with the same numbers that you posted including idle at 85F+ 199- 204F for now on my Ultra Gauge.

When you say 30k on the cooling system can you shed some more light on it? Was this 30k after replacing just the cooling system like radiator & hoses? What was the actual mileage on your 04' when it cracked?

I find myself having done similiar mods just as preventative maintenance. I recently bypassed the t-body heater plate. My D2 has what feels like a slight miss in the idle but no codes. Drives me crazy after upgrading to Kingsbourne wires, new Bosch coils, Champion plugs, new downpipe gaskets, new expansion tank and coolant. You know about the block problems in the back of your head and hope that the block and liners will be ok when the head gaskets eventually have to be replaced.

Typical 03- 04' D2 owner paranoia. Then it is a drive and watch saga not that you can do anything much different.

 

My Disco has about 122,000 on it. Everything in my signature, and more was done since 90,000. The radiator, hoses, reservoir, and cap have about 25000-30000 on them. Coolant and 180 oem thermostat less than one year and 5000 miles on them. Aux fan and heavy duty fan clutch with new fan blade both installed this past year. Never overheated before this. Head gaskets done at 90,000 as preventative maintenance. I really couldn't have done anything differently. I'm just looking forward to enjoying a reliable engine that I don't have to worry about. I plan to change the hoses, thermostat, and reservoir with cap every 60,000 miles on the new setup. Coolant every 30,000 miles. Truck should last a long time I hope. It has some rear frame rust. I plan on having a rear quarter or half from Rovers North welded in within the next 3-5 years. Should be solid then!

 

Wow! That is a firm commitment! Can't say I blame you on your game plan. Head Gaskets done as preventative maintenance? That says it all! Going to check out your Signature.

 

In my case I caught it before overheating. Started misfiring on 6. I thought it was bad gas so I put a bottle of Seafoam in half a tank of gas and it seemed to clear up for a short while. Then it fouled the plug and started really misfiring. That's when I noticed the coolant in the cylinder.

Same when the head gaskets went it was a slow leak out the rear of the passenger side head. caught that before any overheating. As well when the front cover gasket went out last October... one day there was a puddle on the floor of the parking garage... never overheated. In fact I filled it up with water and drove it home from work without overheating!! (4.5 miles city streets.)

Have had the Ultragauge since before the head gaskets 4 years/60k ago. Would not go without one.

I have been checking out all of my options and I will also replace the engine and keep my "known quality" truck rather than start over from scratch.

 

Have you considered an LS Swap? There is a shop in Ohio doing them. I like the 4.6, but an LS would be sweet.

https://landroverforums.com/forum/discovery-ii-18/trailhead-chevy-ls-engine-swap-82431/