My son has a 2001 Disco (very clean out of Kentucky) and about a month ago, out of the blue it started making a noise that sounded like an exhaust leak - coinciding with a cylinder and increasing with revs. OBD threw a misfire code. It had never overheated (has a scanguage and alarm set), and there was no oil/coolant intermixing. After poking around, I found the leak was at the head/block junction near cylinder 5. I could feel a puff of hot air every time the noise was made.

So, thinking that a pro could knock this repair out quickly, I rented a trailer and towed it to a "trusted" shop that gave me a reasonable estimate to replace the head gasket, but after looking at it briefly and not disassembling anything, they said we probably needed an engine and the repair would run in the $17,000 USD range. That's a non-starter for us, so I started looking at reman engines, LS swaps, etc, then decided to do my due diligence first.

I removed the head and immediately found the issue - a blow out in the head gasket at cylinder 5. After removing the gasket and doing some cleanup with brake cleaner and a shop rag, the block and head seem fine - at least no visible damage, and no surfage irregularity that I can feel. I have a straightedge on the way to do a more careful assessment.

I'm going to take the heads to a machine shop to be hot tanked (skimmed if needed), new valve seals put In, put a new gasket set on (gasket kit and head bolts on the way from Atlantic British already), and see how it goes from there. Hopefully we'll be back in business for under $1000 instead of $17000.

The moral of the story to me is to trust yourself and don't buy into "trusted" shops if something doesn't seem right.

I'll do a search on the following question, but if anyone has an opinion, I'm interested - what is the best way to clean up the block surface without damaging metal? Dave on the Atlantic British video says that they use a blue cookie on a die grinder. I'm looking for the most home shop friendly solution.






PS, The coolant in the cylinders is from when I took the head off and it drained from the coolant passages into the cylinders. I dried it out immediately after this snapshot.

 

Good news that it’s just a head gasket. From the photos (on my phone) I’m not really able to see it well. You don’t want to get too aggressive on that surface. I’d try a Scotch Brite pad by hand, or possibly some fine sand paper on a block to keep it sort of flat. If using sand paper you’ll want to try to keep the grit from falling into the cylinder. Stuff a rag into the cylinder to keep as much foreign material out as you can.

 

I would stay far-far away from power tools when removing the the old gasket material from the block. You can easily remove too much material (leading to poor HG seal) and it sprays dirt/grit everywhere! Your block surface does not need to be shiny; just flat and clean. My recommendation would be using a carbide scraper (brand name Super Scraper) and brake clean with a lint free rag. Also make sure you blow out all the bolt holes with compressed air and its a good idea to chase all the threads.

 

What makes this an interesting failure, rather than just a regular head gasket break?

 

I've never seen one like this and nothing came up in my forum searches as similar. Maybe it isn't interesting. Sorry. I can delete the thread if it is polluting the forum.

 

The threat comes from what caused the head gasket failure. My Rover V8's gasket failed and was replaced 50,000 miles ago and I haven't had an issue in all that time -- not another failure, no coolant loss, no emulsified oil... So it could just be a gasket failure and nothing else. In that case, you can replace it and be good to go. On the other hand, it could be that the jacket behind the cylinder liner is cracked and blowing coolant up along the outside edge of the liner. In that case, it will require the replacement of the liner with a "top-hat" liner, a rebuilt short-block, or an engine swap. The $!7K estimate is for a rebuilt long-block with top-hat liners (flanged sleeves) and the labor of a shop that doesn't want to do the job.

Since you obviously have the skill to do the gasket swap, that's the sensible place to start. If that doesn't resolve the issue and you continue to see coolant loss, then there are more economical options than the deluxe solution quoted. Swapping in a used Rover V8 could be the cheapest route if you can find one that doesn't have the same problem for a good deal. Otherwise, reman short-blocks are ~$5.6K and long-blocks are ~$8K and if you do the labor yourself or find a shop that's willing to do it for a couple thousand bucks, it won't be nearly $17K, but could still be a lot for a vehicle that can barely be sold for as much as it would cost you even after the work is done.

 

American British has long blocks for ~$6K and a LS is about the same money, all in.

We never had any coolant loss. I don't see the downside of trying a head gasket first. There is no evidence of oil in coolant or coolant in oil, and no visible physical damage.

I'm a Land Cruiser guy. We don't see this kind of random failure. My 80 has 300K miles and my 200 has over 100K miles without a hiccup. But my son loves this disco, so I'm trying to keep it alive.

With the cost of used vehicles and the associated uncertainty, repairing this one seems like a reasonable option. And it is my son's first car, so he's somewhat attached to it.

 

Hopefully it’s just a head gasket. The D2 is a really great choice for your son (it’s the opposite with me and my son, I’m the LR guy and he’s the Forerunner guy). The 2001 engines aren’t highly prone to cracking blocks. The vehicles are awesome once you get the glitches sorted out. And if maintained and not overheated they are pretty reliable.

 

I like to use a wire wheel on a die grinder to clean the block surface. I keep it angled so that the wire is parallel to the circumference of the cylinder. Any grooves or microscratches created serve to anchor the gasket against the pressure of the cylinder. That particular failure is fairly common on the D2. It is partly design related (four head bolts vs 5), partly temperature related (even though you did not "overheat", the thermal expansion of aluminum is much greater than steel and ideally should not be operated over 200 degreesF) and partly compression ratio (rather high at over 9:1).

 

What years were highly prone to cracking?