Tampilkan postingan dengan label land rover engine failure. Tampilkan semua postingan
Tampilkan postingan dengan label land rover engine failure. Tampilkan semua postingan

Selasa, 29 Oktober 2013

Should You Rebuild or Replace Your Land Rover V8?



That is the question facing more and more Discovery II owners as their engines age.  Land Rover’s Buick-designed aluminum V8 engines were never paragons of reliability; engines in the last P38 Range Rover and Discovery II models are arguably their worst.

There are three common failure modes.  Most common is the overheating failure, where the engine consumes coolant for a while and then overheats whenever it’s driven. Sometimes people fail to catch this in time, and the engine is driven till seizure.

Land Rover V8 with block failure behind the liner.  Coolant scours the piston clean
I've got several articles on liner failure online.  Here is the latest one.  This story explains the process in detail.

The next failure starts with oil pressure loss. The post-1998 oil pump is integrated into the front cover, and it’s prone to wear out over 100,000 miles.  If the pump merely wears you get low oil pressure, and a light at idle.  That can actually be fixed with a new front cover.  However, it’s often accompanied by worn main and rod bearings.  We’ve also seen the thrust faces break off the center mains, and either of those failures will necessitate engine overhaul.  If the pump actually fractures internally you can get total loss of pressure, and engine failure if the warning light is ignored.

The gear in this oil pump broke into pieces

The final failure is unacceptable motor knocking.  Sometimes this comes from lifters or rocker shafts but more often the noise is deeper inside - in the pistons.  We’ve also heard heavy noises from the lower end. The piston skirts wear and the motor starts knocking, first when cold and then all the time.  There’s no cure for this short of complete overhaul.



The only cure for excess piston skirt clearance is new pistons

It’s said that the production tooling had worn out but Rover continued to use it.  However it happened, the result was a series of engines whose internal clearances were at the wear limits before they even left the factory.  Internal balancing was abandoned to save costs, and finish quality dropped. Internal stress increased as the rated power was raised; first in 1999 and again in 2003.  The final straw was extra heat from leaner running; these motors were beyond their limits to achieve post-1997 emission compliance. 

Where the engines in older Rover models often went 200,000 miles or more, these final series motors seldom hit that mark. Most fail by 120,000 miles and a few don’t even reach 60,000. They seem to have gotten worse with age.

So what do you do about it?

Over the last decade, used Land Rover values have fallen and repair costs have risen.   Short block engines cost just $1,000 in 2004; by 2013 they were $6,000+ if you could find them. Long blocks - with the oil pump and heads - are closer to $8,000 Even so, the repair decision remains easy on a Defender, where vehicle values are usually above $50,000 and holding.  No sensible person would scrap a Defender for mere engine failure.  The situation is different for Range Rovers and Discoveries because those vehicles may be worth less than $10,000, and total repair costs can easily exceed that number.

If you’ve got a Rover whose engine is on its way out you basically have three choices:
  • Scrap the truck;    
  • Install a used motor;
  • Rebuild your motor, or buy a rebuilt motor.
Some people will read this and ask, what about a different motor, a Chevy or Toyota conversion?  If you've got an old Rover, and you live in a place that does not have emission testing, that is an option. Unfortunately most 2000-newer Rovers in America are subject to emission test, many through the OBD port, and an engine conversion will not work for them.  Your conversion options are mostly applicable to 1995-older trucks without OBD II.  It's also worth noting that a high quality engine conversion is often 100+ hours of work, so there is no cost savings to this route if you pay to have the work done.

If the Discovery is “just a car” to you, the scrapyard option may look attractive; people in that position tend to move on to other brands of car.  Major repairs are what separate the serious enthusiasts from the weekend dilettantes.  The weasels get a can of gas and a match, and get ten grand from the insurance company.  A few good men take their own ten grand, and do a proper repair.  Then they go out and burn the gas, chasing action through backwoods and beaches. 

If you are dedicated to Land Rover, and like the separate frame/live axle design of these trucks, you know there is no present-day equivalent.  As an off-road platform the built-up Discovery II outperforms the Defender in many situations, with vasty improved civility and much greater family acceptability.  If you agree with all this, and your truck is in good shape otherwise, the most sensible option may well be repair.

That leaves you with a choice of engines.  I’m often asked about used motors for these trucks, and I am never in favor of that idea.  The reason:  any used motor you find is going to be 10 years old at least.  If its not worn out, it’s going to be well on the way.  Worst of all, any used motor is going to retain all the design flaws the motor you have now has, and it may blow up a month or two after installation.  When I look at the cost of used motors and the effort it takes to put them in I think you’d be nuts to choose that route.

If you’re still thinking about that notion, just remember that your late-series Land Rover V8 was a fatally flawed design.  What sense does it make to put another flawed motor in your rig?

To me, the only option that makes sense is the fitment of a flange-liner motor with a new front cover; one where the late series design deficiencies have been addressed.  That is the solution that leads to long term reliability.



I’ve written several articles about the use of flanged liners to fix overheating in these engines.  When that technique is combined with new pistons and an updated front cover, and the motor is blueprinted and balanced you end up with a rugged and smooth running engine that will last a long time. 

A rebuilt Rover engine, ready to install
Robison Service has been rebuilding engines like that for several years; it’s the only way we do Land Rover V8 motors now.  Other companies in the UK and the USA are offering engines with various combinations of parts and technology.  In my opinion that is the way to go.

There are still a few “old style” short blocks in the market with the original Land Rover tube liners.  I suggest avoiding those motors as they have all the flaws of the original engines.

Now for the final question:  What will it cost:

*** SPRING 2016 UPDATE: The total cost, parts and labor, to rebuild one of these Land Rover V8 motors, including removal, teardown, overhaul and refit; fit flanged liners, and do all the other work that's typically needed runs $12-15,000.  It's a significant commitment and there are no good shortcuts.  ***

A set of pistons, flanged liners, bearings, and other parts to rebuild a short block will run a bit more than $3,000.  The machine work to rebuild a short block is substantial.  Here is what we do in our shop:
  • ·      Tank clean and bead blast the block
  • ·      Remove the old liners and check for cracks
  • ·      Repair the cracks
  • ·      Check the block for straightness, corrosion, and other damage
  • ·      Machine the block to accept flanged liners, and install the liners
  • ·      Bore liners to match the new pistons
  • ·      Rebuild crank and rods
  • ·      Line bore block if needed; deck cylinder head surfaces;
  • ·      Balance rotating mass
  • ·      Assemble short block
We can change displacement from 4.0 to 4.6, or something a bit larger.  Upgrade costs can be anything from $1,200 up.  Other shops may follow different steps, or a subset of these steps.  Not all blocks are rebuildable; a few are too damaged from overheating.  Expect the total cost for a rebuilt short block to be in the $5,000-6,500 range; more for custom work.  You can rebuild the block you have (that's what we do most of the time) or you can buy an exchange block, already built.  

Then you get into the rest of the job . . . 

Add a couple thousand more to rebuild the heads, replace the front cover and take care of the other rebuilding work.  That gives you what rebuilders call a "long block" - a complete motor less the covers, accessories, brackets, hoses and wiring.  Those too can be purchased or made.

A wise owner looks at the ancillary items – things that should be attended to when the motor is out. New water pump, hoses, motor mounts are just a few possibilities.  You may need a radiator, or AC work, or a steering box and lines.  Those costs should be added in for a first-rate job.  You should also consider cosmetics - do you care how the engine bay looks?  If you do, this is the time to refinish or re-plate under hood pieces while they are all out and apart.  The change may be striking:

A restored D90 engine bay
Finally there is the labor to do the job; expect this work to consume 30-40 hours at whatever labor rate prevails in your area; more if you get into detailing or custom work.  Jobs like this typically cost $11-14,000 in my part of the country, as of fall 2014.


It’s expensive, for sure, but it’s the only repair that’s going to last.  If you have a Rover V8 and you want to preserve it I suggest giving this plan serious consideration.

1995 Range Rover Classic atop Killington Mountain
Note:  The advice in this article applies to any 1987-newer Land Rover with V8 engine.  If you have a pre-1999 engine you may not need the flanged liners but the rest of the job is essentially the same.  Owners of older cars should also consider a diesel conversion, something that is not possible for those of us with newer vehicles in states where emission testing is a requirement.

Here are three articles about internal problems in the V8s:

V8 engine failures - slipped liners and more - from 2009

Should you rebuild a failed Land Rover motor? I have an article about that situation here that covers the decision process

What's the latest on top hat or flanged liners? This article tells all you want to know about the flanged liner overhaul

Discovery II models also have a problem with frame rust.  We first began to see this in the spring of 2014, when we saw several trucks whose rear frames rusted right through over the winter.  These vehicles seemed more vulnerable to rust than the earlier models.  Read this article to find out why, and what you can do about it.

Are you thinking of restoring a Land Rover?  This article shows some of what's involved.  This article explains the difference between repair and restoration, two very different processes.

If you drive a Range Rover Sport or LR3, read this story on differential failures

And if your supercharged Rover is losing power - read this

Programming keys for your Land Rover is here

(c) J E Robison Service


John Elder Robison is the founder of J E Robison Service, independent Land Rover specialists in Springfield Massachusetts.  John has been part of the Land Rover community for 28 years; since the marque’s 1987 return to North America.

Rabu, 05 September 2012

Flanged or Top Hat Liners in Land Rover Engines

The more I see of the 2003-4 Land Rover Discoveries, the more it seems their engines were fatally flawed.  Ten years ago, 90% of the engine problems from overheating were due to heads warping or head gaskets failing.  10% were due to what people called "slipped liners."

The same was true for noise complaints.  When someone came in with a rap or tick issue the problem was almost always a noisy catalyst or worn rocker shafts - comparatively simple fixes.  Only a tiny fraction of noises were from internal motor problems.

Today, with the late Disco motors, those odds have flipped.  When a 2003-4 Rover comes in with overheating trouble, the most likely cause is liner or block failure.  A noise complaint is more likely to be from excess clearance in the piston-liners (in other words, prematurely worn out.)   I've written several essays about how this happens so I won't repeat all that here.  The question is . . . what do we do about it?

The solution that has emerged - both here at Robison Service and in the UK - is to rebuild the blocks using flanged liners so the cylinder head seals against the liner, not the block.  Then we fit new pistons with proper clearances.



The photo above shows a typical failure.  The block cracks at the base of a head bolt bore, between the back of the liner and the water jacket.  With the stock liners there is no barrier to prevent combustion gases going round the liner and into the coolant.

The fitment of flanged liners solves that problem by making the liner top the sealing surface.  There is no high pressure gas behind the liner, and the cracks are rendered irrelevant.



The photo above shows a flanged liner and a new piston.  The o-ring seals the bottom of the liner to prevent coolant dripping into the oil sump in the event of a crack.



This is what a flanged liner looks like installed.  As you can see the wide flange covers the entire sealing area of the head gasket.

We can do flanged liners in 4.0, 4.6, and overbore configurations.  At this moment (Sept 2012), costs to do a block with flanged liners, new pistons, and all basic machine work in in the $4800 price range.  Our American costs are similar to costs from RPI or Turner over in the UK.

We believe this is the only long-term solution to the problems in these late motors, and it provides a substantial upgrade for any older Land Rover V8.  However, the liner repair is just the beginning when it comes to engine overhaul . . .

What else do we do when building a motor?

I recommend balancing any engine.  Motors like these rely on sophisticated engine electronics to achieve smoothness.  That will be considerably improved if the engine is mechanically balanced before assembly.

Front covers and oil pumps have been problematic on these trucks.  The pump gears fracture, and eventually the oil pump fails.  The result - engine failure from oil starvation.  I recommend fitting a new front cover as long as these parts remain available.

Heads are another problem area.  We recommend rebuilding the heads.  This involved walnut shell blasting to get everything spotless, followed by crack test and a check for warping.  Then we fit new guides, redo valves and seats and cut the sealing surfaces perfectly flat.  If you're a perfectionist we can also cc the combustion chambers to ensure each cylinder is exactly equal.


This is a rebuilt head.  As you can see the sealing surface is cut to a mirror finish.  We true these heads to half a thousandth of an inch to minimize the change of gasket failure.

We also rebuild rocker shafts, and swap cams and lifters.  Needles to say, every other part is cleaned and inspected before being overhauled, repaired, or replaced.   That thinking should also extend to the external accessories like the water pump, injectors, and alternator.


We believe the engines we are building now are substantially smoother and better than what land Rover delivered new.

Till next time
John Elder Robison
J E Robison Service
Springfield, MA USA

Here are three articles about internal problems in the V8s:

V8 engine failures - slipped liners and more - from 2009

Should you rebuild a failed Land Rover motor? I have an article about that situation here that covers the decision process

What's the latest on top hat or flanged liners? This article tells all you want to know about the flanged liner overhaul

Discovery II models also have a problem with frame rust.  We first began to see this in the spring of 2014, when we saw several trucks whose rear frames rusted right through over the winter.  These vehicles seemed more vulnerable to rust than the earlier models.  Read this article to find out why, and what you can do about it.

Are you thinking of restoring a Land Rover?  This article shows some of what's involved.  This article explains the difference between repair and restoration, two very different processes.

If you drive a Range Rover Sport or LR3, read this story on differential failures

And if your supercharged Rover is losing power - read this

Programming keys for your Land Rover is here

(c) J E Robison Service

John Elder Robison is the founder of J E Robison Service, independent Land Rover specialists in Springfield, MA.  John's shop has supported Land Rover owners since 1987. They are experienced at all aspects of service, repair, overhaul and restoration.  Find Robison Service online at www.robisonservice.com or on the phone at 413-785-1665.


About the author:

John Elder Robison is the general manager of J E Robison Service Company, independent restoration and Bosch Authorized Car Service specialists in Springfield, Massachusetts.  John is a longtime technical consultant to the Land Rover, Porsche, and Rolls Royce Owner's Clubs, and he’s owned and restored many of these fine vehicles.  Find him online at www.robisonservice.com or in the real world at 413-785-1665







Kamis, 15 September 2011

When engines run too fast, or too lean . . . valves break

Last week, we received a 1990s Range Rover Classic that ran rough and made some noise.  A local garage had changed the plugs and wires, to no avail.  They did a compression test, and found one dead cylinder, with 25 PSI compression.  A normal reading on a truck like this is 175.  That's when the owner decided to ship the rig to us.

We did a leak down test, where we put air into the cylinder through the spark plug hole, to see where it comes out.  Air came out the exhaust as fast as we put it in.  There was only one thing to do - we pulled the head.















We found just what I expected - a burnt exhaust valve.  You can see the two valves in the cylinder head photo above.  The intake is on the left; exhaust on the right.  See the ragged edge on the right side of the exhaust valve?  That's the failure.  Here's the valve, removed from the head:















In this photo the failure is unmistakable.  That was where the story got complicated.  The owner said, "The engine only started skipping after I got the truck back from having a new transmission installed."  I asked why he had the transmission changed.  "It stopped shifting gears," was his reply.  "It stuck in low."

I decided to look at little closer.  Look real close at this photo of the piston.  Note the little line just below center right:




















It looks to me like the valve touched the top of the piston, ever so slightly.  BTW, the liquid in the cylinder is residue from disassembly.  It has nothing to do with the repair.

I thought about what the owner had said, and I concluded one of two things must have happened.
A - He ran the engine too fast because the transmission was stuck. As a consequence, the valve "floated" and hit the piston, causing it to fail
B - The engine was racing way too fast with a light load because the transmission was stuck.  As a result, it ran too lean, and the lean running caused that cylinder to overheat because its injector was a little marginal.

I don't know which explanation is correct, and of course one of you readers may suggest something totally different.  For now, I am going to use my best judgement and recommend we change that injector, and fix the valve.  Changing the injector covers both the bases for us.  The trans repair took care of the over-revving, and the injector will take care of possible leanness in that cylinder.

As you can see, there is no sign of damage on the cleaned up piston:



















The valve looks just as fried as ever.  We'll fit a new one, and new springs just to be safe.  We will also touch up the valve job on all the other cylinders and clean up the seats.




















If you go back to the top photo, you'll see there was black carbon all over the valve.  What does that tell us?  It says someone tried to drive this truck a ways with the failed cylinder.  That suggests it may have failed earlier than the owner thought.  However, it does not change the diagnosis.  

Is there a moral to this story?  I think so. When your car starts to fail, or act at all unusual, park it.  Don't drive it home and then say, "it sounds funny."  By the time you get there, it may be too late.  This fellow started with a transmission repair, but when he kept driving, it became an engine repair too.

In his defense, I must say that we see this all the time. Modern cars have loud stereos and lots of sound deadening around the motor.  Most of the lights and gauges we had 20 years ago are gone.  It's easy to drive today's vehicles until they go up in smoke, and then ask ourselves, "How did that happen?"

As owners (I am an owner too, not just a repair guy) we have to be extra observant because the sounds and smells that used to warn of danger are no longer there for us to see, unless we look real close.  Check your fluids every now and then, and if you ever feel something may be amiss, slow down, open a window, and listen and smell.  It it ticking?  Does it smell hot?  Is that gauge pinned in the red?

In the end, if our cars fail, we pay the price.  So it pays to be vigilant.

Senin, 27 Juni 2011

A new Land Rover engine failure

Have you had an oil pump fail on a 2000-2004 Land Rover V8?  At Robison Service, we are seeing pump failure more and more.






Last week we encountered a 2003 Discovery with a failure I have not seen before.  The car came to us with an oil light on most of the time, and lifter noise when the light was on.  The noise vanished as soon as the light went out, confirming that the car has a problem with oil pressure, and not a problem with the oil light sender.

This engine is reasonably clean, and free of sludge.  This wasn't a neglect issue.

We removed the front cover, and found the oil pump fractured.  I have seen several similar failures in the past year, but most of the time, when we get them, the engine has already blown.  This one had not.  The outer gear of the pump had fractured into four pieces.  I don't know how much longer it would have worked before failing entirely but it was clearly close to the end.



















I thought we should pull the oil pan to check the bearings, and to my surprise we saw this laying in the pan.  As you can see, the pan is otherwise pretty clean.  The spots in the image are just bits of crud you see in any oil pan.  There is no metal or evidence of damage visible.  The oil is normal looking.





































The crescent piece you see is the thrust face from the center main bearing cap.  With no washer in place the crank moves back and forth a few mm.  I think this is the original failure . . . I think the center bearing broke for some reason, the crank moved back and forth over a period of time, and that led to the eventual cracking of the oil pump gear.

Had we not caught this, the engine would have failed in the fairly near future. We will repair the bearing and time will tell how that holds up.  I have some concerns because the crankshaft face may be galled. and that would ruin a new thrust face in short order.  If we find that we face the choice of filing it in place, or removing the engine and essentially getting into an overhaul situation.

Now that I know this I realize we can check for the problem on an assembled motor by moving the crank pulley back and forth to check for excess play.  I wonder how many more of these are out there, waiting to fail?