You’ve come to the dreaded realization that your Land Rover needs new head gaskets. Now what? Take it to a shop? Do the job yourself? Sell the vehicle? Your decision may depend on your time, budget, and confidence in your mechanical aptitude. This article details my experience as an amateur mechanic taking on my first head gasket replacement project. Hopefully it is valuable as a resource for others finding themselves in a similar situation. My patient was a 1998 Land Rover Discovery 1, but this article is equally applicable to other models with the Rover V8 engine: Discovery 2, Range Rover Classic, P38 Range Rover, and NAS Defender.

Disclaimer: the content in this article reflects my own amateur experience and that of others in performing this repair. It is not professional mechanical advice. Individuals undertaking the project described here do so at their own risk. Auto repair can be dangerous. You might hurt yourself or damage your vehicle. If in doubt, seek professional assistance. Follow the suggestions in this guide at your own peril.

It’s also worth mentioning that replacing head gaskets won’t necessarily be a comprehensive solution by itself to overheating issues on the Rover V8 engine. If your head gaskets failed because your 24-year old radiator is clogged or your fan clutch doesn’t engage, then those problems will still be present and may cause overheating again. In addition to replacing your head gaskets it’s worth evaluating and updating your entire cooling system as necessary, otherwise you might need to do the job again soon.

1. Decision: leave it to the pros or do it yourself?

We’ll take it as a given that you are 100% sure that the problem is a failed head gasket and not another issue, like a slipped cylinder sleeve or a cracked engine block. It’s worth determining this with certainty, because the course of action is different for each of these problems. The choice between taking your Rover to a shop versus tackling the repair yourself often boils down to time, money, and your mechanical aptitude.

The quote my local independent Rover shop gave me for the job was $2,500 and that was reasonable. If you choose this route, I strongly encourage you to entrust your vehicle to a Rover specialist and to know exactly what that quote includes. Doing the job right involves resurfacing the cylinder heads, so make sure your quote covers this step.

I chose to take on the project myself as a learning opportunity. It took me longer than most people need – 32 hours of shop time over the course of a week – but it was less expensive, I knew exactly the quality of the work, and I gained a wealth of experience. If you plan to own your Land Rover for a long time and want to gain proficiency maintaining it, this project is a good one to pursue.

2. Budget

Here’s what I spent on my head gasket replacement project. Your individual costs may be more or less depending on what additional work you choose to pursue. This presents the classic situation of “while I have everything apart, I might as well replace _______,” so set your expectations accordingly.

Head gasket kit & new radiator hoses: $280
Hand tools: $90
Plugs/fluids/filters: $70
Head resurfacing: $130
New valve/valve job: $280
Pizza & beer: $50

Total cash outlay: $900

This is near the high end of the range of what you can anticipate spending.  Your costs will be lower if you don’t need a valve job, if you already have the tools you need, and if you don’t need to entice your friends to come help by providing refreshments.  At minimum you’ll need a the head gasket parts kit, new fluids & filters, and head resurfacing.

3. Preparation

The technical difficulty of replacing head gaskets is not high, however it is a detail-oriented and time consuming project.  In order to make it go smoothly as possible I put a lot of effort into preparations.  I wanted to avoid disruptive trips to buy parts and hardware.  This investment up front paid off, and if you are going to take on this repair then I encourage you to plan ahead thoroughly.

First, I spent hours doing homework.  I read all the head gasket threads I could find in the technical section of online Rover discussion fora, like DiscoWeb.  There are a lot, and it was confusing to make sense of them all before getting into the project.  A helpful step I took was to copy and paste certain comments from the various threads into a Word document, then I organized them by the order of operations.  This way I could anticipate where other folks had run into problems and avoid their misfortunes.  This list of tips is included later in this article.

An essential resource for the job is RAVE. This is the factory service manual for Land Rovers. You can download a PDF of it for free here. The manual includes detailed diagrams, directions for removal and replacement of components, and torque values for hardware. Plan to keep a laptop or tablet computer in your workspace to consult RAVE during the project. If you don’t want to get your computer grubby, print off copies of the sections you’ll need.

Recruit assistants. Having competent help was a key to success. Nearly every day of the project I had a friend come over to lend a hand. Some steps are hard to do alone, plus having the company made the process more enjoyable. Choose wisely, however: a careless helper is worse than no help at all.

Watch videos about the project. This will help you understand the big picture, the general progression of steps, and the specific steps that are critical, such as the torqueing sequence for the head bolts.

Find a local machine shop that can resurface your heads (preferably one familiar with Rover heads) and get a quote. If you want to save time, you can buy resurfaced and rebuilt heads from Will Tillery in advance. This may add to the cost, but it is a sound investment.

Specific tools and materials you will need include:

5/16" 12-point deep socket for the valve cover bolts
12mm 12-point socket for the exhaust manifold bolts
Impact swivel and sockets including 5/8” (I broke a universal swivel on a head bolt, impact-grade tools are helpful – especially on the head bolts)
Socket extensions and different sized drivers
Torque wrench – make sure you it operates within the range of torque values you’ll need to apply (consult RAVE to verify)
Masking tape and felt-tip marker for labeling connections and labeling contents of...
Zipper bags for storing bolts, clips, all the small pieces you remove during disassembly
Fan clutch wrench
Breaker bar with handle extension (the bottle jack handle works)

Additional tools and materials:

· Large sheet of cardboard

· Thick leather gloves

· Headlamp

· Compressed air (either canned or from electric compressor)

· Toothbrush

· Parts cleaner

· Siphon hose

· Antiseize compound

· Thread sealant (i.e. Loctite)

· RTV/Right Stuff

· Rags

· Spark plug socket and gapping tool

· Paint pen

4. Disassembly

Having never taken my engine apart before, this was one area that gave me challenges. For other first-timers, I suggest approaching the disassembly in small chunks, thinking about your engine as a big collection of smaller systems. You approach each system and break it into its component parts and then it's much easier to conceptualize. If you think "I have to take all this apart!" it can be overwhelming, but if you break it all down into smaller tasks then it's manageable. Here are some things I did to make everything easier to put back together:

Take photos, especially close-ups of the engine so you know how it is supposed to look at different stages of assembly.
Label connections. Every time I unplugged something I made tags for each end of the connection using masking tape, and with the felt-tip pen I labeled them. "A" matched with "A", "B" matched with "B" and so on. It added some time but when it came time to put everything back together I knew exactly what went where and in what sequence.
Label parts. Each time I removed something I put it in a plastic bag and wrote on the bag what it was, like "Valve cover bolts left side" or "PS pump, long bolts for housing, short bolts for pulley". For bigger parts, like the rocker arms, I set them down on cardboard under the truck and wrote on the cardboard "left, front" to maintain proper orientation. I also labeled the orientation of the push rods "Top, front to back". Everything that came out of the engine was recorded and cataloged so I could put it back in the right place, in the right sequence, correctly oriented.
Take notes. It may not be obvious how to reverse the steps when it's time to put everything back together. If you take notes that you did X before Y, then you'll know to do Y before X during reassembly. This could be as simple as recording voice notes on your cell phone.
Throw stuff away that you don't need. Parts you know you are replacing, like head bolts and spark plugs, make no sense to keep once they are removed.

In general, try to be methodical, orderly, and organized. It will make a huge difference in how efficiently (and correctly) you can put your engine back together.

5. Reassembly

Use help. There are lots of steps in the process that are easier with assistance. Go slow. Think about each step before you tighten everything to torque. I got ahead of myself on a couple of occasions and had to take some things back off in order to get a sequence right. This is where the notes are a good reminder. Also, from the point at which I set the heads onto the block I covered the intake holes with masking tape. Then when I put on the intake manifold I covered those openings with masking tape. Then when I put on the lower plenum I covered the pipes with masking tape. I wanted to avoid dropping anything into an intake. Just remember to remove the tape when it's time to install the next layer of components.

6. Encountering problems

I don't know if there is a "routine" head job. I put a lot of effort into avoiding certain problems that other people had run into, which I managed successfully, but I had my own share of surprises that slowed me down.

Bent valve: the machine shop found a bent valve. It seemed foolish to go through all this trouble to replace my head gaskets without fixing a valve that would cause me trouble later, so I agreed to a new valve and full valve job. It added to the cost of the job but in the long run I think it will be worth it since I plan to keep my Disco for many years.
Exhaust manifolds: one of the threads on a bolt hole in the cylinder head was damaged and I was unable to seat the manifold bolt. I bought a tap & die kit to re-tap/restore the thread and it worked after extensive persuasion.
Valve cover bolt: a buddy of mine sheared off a valve cover bolt during assembly (see note above about competent help). He brought over a bolt extractor kit, and while I was nervous drilling into the bolt stud mere millimeters from the cylinder head the tool worked and I was able to remove the buried stud.
Leaking fuel injector: plugging all the injectors back in was awkward, and during the process one of the O-rings came unseated. When I finally turned the key all I got was a stream of gas flowing over my engine from the fuel rail. I had to take a few things apart to reach the leaking injector but re-seating the O-ring solved that issue.

7. Assorted tips and suggestions

I culled these from head gasket repair threads in the archives of DiscoWeb. Follow at your own peril.

When you take your heads in to be resurfaced, they run them through some sort of chem dip to remove all of the gunk and carbon and they will come back looking brand new. Take your valve covers and rocker assemblies with when you drop them off and have them clean them too. The shop I used did it for free with the heads and It saved me two hours with a tooth brush and cleaner.

Head bolt removal:  you can also use a 6pt 3/8 socket on a 3/8 to 1/2 adapter for use with a 1/2" breaker bar. has worked for me every time and no banging the firewall needed.

It's a good practice to get everything done to the heads including valves, stems, pressure test, degrease, and resurface. That leaves fewer things to give you issues in the future.

Just a note when you put it back together so you don't make the same mistake I did:  make sure you get the wiring harnesses in the right places.  I forget which sensor it is for but its wires sneak in between the engine block and the water pump (might be PS pump, I forget).  Make sure you have it in the right place otherwise you'll have to take the pump back off which is a pain.

Getting the alternator out was a hassle.  Some of the multiplugs were on pretty good. Getting the coil pack bolts off of the intake was the biggest pain so far- crawling into the engine trying to find the outer bolts in the limited space, limited vision, and mess of wires... and it turns out you only have to do the top bolts to get the intake off.

When removing head bolts (and installing new ones), get your helper to press the socket firmly onto the bolt head while you gradually apply force to the extended breaker bar. This will maintain good contact between the tool and the bolt, reducing the chances of rounding the bolt head.

Wear thick leather gloves when removing the head bolts.  When the bolts break free, they send a sharp vibration through the tool that is not pleasant.  Gloves help to insulate from that.

When you put it back together, spray the ends of the new HG around the water passages with high-tack spray.  Make sure you blow out the tapped holes for the head bolts before threading them in.  Lightly oil the threads and put a dab of white grease under the heads of the new headbolts before torquing.  Get new intake bolts and make sure to put extra sealant on the bolts that go into the water passages.  Put a little glob of Right Stuff in the corners where the heads meet the block at the front and rear valley (where the rubber valley end seals fit). Be VERY careful lining up the lower intake plenum gasket. Do not final torque the retaining clamp bolts until the intake is lined up and you have all the bolts started.

I high-tack spray the valley gasket around the intake ports as well- I have seen a lot of vacuum leaks from here.  Be VERY careful re-installing the heater pipe into the intake manifold. Replace the O-ring on it and grease it up really well before sliding that pipe in there. Coat boat sides of the valve cover gaskets lightly with Right Stuff.  Loctite the valve cover bolts and torque them evenly. Replace the throttle heater plate while you’re at it. Make sure the ends of the throttle heater hoses aren't damaged. High-tack the new throttle heater gasket. Put lots of high-temp copper anti-seize on any bolt or stud in the exhaust system.

For future reference, there was no need to remove the alternator, you only have to remove the bracket assy and move it to the side. There is a lot you can leave intact.

I always mark my heads and such when taking to a machine shop to make sure I get my own back.

Gaskets: as they say in Jamaica, red stripe up mon! Don’t forget to clean the block! and don’t forget to blast air into A) the water jackets (I do this to ensure things are nice and dry on install) and B) blast air (using a computer keyboard cleaner air thing if necessary) into the head bolt cavities on the block. Get that cleaning material and coolant and oil out of there!

Use the paint pen to mark the head bolts before doing the 90 degree sequences. The tech in the AB video just estimated 90 degrees. I found it hard to get clearance for a full 90 degrees.

8. Conclusion

The notion of taking your engine apart and putting it back together correctly can be intimidating if you’ve never attempted a project of this scale before. I remember looking at my bare engine in pieces thinking “My God, what have I done?” Yet it all worked out in the end and my Discovery ran wonderfully. Not only did I gain a deeper understanding of my Rover’s mechanical workings, I developed confidence that has helped me on subsequent projects: if I did my head gaskets, I can do __________. There is also a closer bond you gain with your vehicle from working on it yourself. The head gasket repair is a rite of passage in the Land Rover community and completing the project successfully is a source of great satisfaction. It can also be frustrating, so hopefully this article helps to make the project a smoother one for you. Please leave comments below if you have other suggestions for tips or techniques on this repair.