100% Proof that liners are moving at 'normal' operating temps & causing the tapping!
So, for those who haven't seen any of my previous posts, I'll start from the beginning. It's a little wordy - but that is me all over!
atriot:
2003 discovery purchased at 107k miles with a ticking engine. Spec of discovery was exactly what we were looking for - A dark grey SE7, black leather, no ACE, heated windsheild, DVD, 2003/4 model year. Discovery also was dealer serviced all its life. Purchased for a good price (because of ticking) from the dealer who had taken it on trade-in from previous (one) owner. Engine was quiet as a dead bird when cold, but sounded like a 1.5 (!) cylinder diesel was hiding inside the block somewhere when the engine was up to normal operating temperature!
We drove LR for just under 1000 miles before stripping down to replace what was believed (or hoped) to be a bad cam follower / camshaft. In that time:
The engine used no water.
The engine did not pressurise cooling system.
The exhaust gaskets were not leaking, SAI valves were not rattling; the noise was definately deep inside engine.
The engine ran smoothly, made good power, used no discernable oil in that time.
Shell Rotella swapped in at 107k miles, the day after the disco was delivered.
100 miles after first oil change, tried seafoam treatment; no difference at all.
The noise eventually became too much for the wife - she was concerned it meant immediate failure, and eventually it was pulled into the garage for work at 108K miles.
On disasembly, it didn't appear that the engine had ever been apart before. Factory thread-sealer still present, head bolts super-tight, factory harness snaps still present, OE landrover gaskets, OE plug wires, etc.
Cylinders / pistons were not steam-cleaned, confirming no head-gasket / water-jacket problems.
Top-end disassembled: camshaft, camshaft drive lifters, head gaskets changed, valves re-faced, stem seals changed, broken oil pump rotors changed, pump alignment fixed, pushrods checked for straightness/length, rockers disasembled and inspected (all perfect). Old camshaft and followers were in perfect condition, as was the parts that could be inspected (no sludge anywhere). Cam bearings were a little worn, but had zero measurable radial float - hence deemed fit for future use!
The old (original) head gaskets had heavy gouges in firing rings on block-side on the middle four cylinders; with VERY heavy gouges on two of the cylinders. These were same diameter as the tops of the liners, suggesting liners moving upwards. Had a pretty sure feeling that the block was bad (that well documented Rover V8 problem), but needed the vehicle fixed quicky.
So, the engine was re-assembled with new parts mentioned above, and new Elring head gaskets, and another fresh supply of Rotella with a genuine LR filter.
On startup, engine ticked again when warm - although not quite as badly as before. Drove almost 10K miles, and the tapping noise had become really bad; the only exception was a 4hr non-stop drive towing 7000lbs, with the engine occasionally labouring hard. Sometime in this trip, the ticking stopped. The Discovery went through 2 (cold-start) drive cycles the follwoing week - being perfectly quiet like it should be. Then, the ticking suddenly started again, and subsequently got worse than ever.
A replacement top-hat engine block was purchased from V8Developments in the UK. This was based on a block from a 1996 discovery, converted to Bosch crank sensor and fitted with new top-hat cylinder liners (sleeves). All parts from the 2003 engine will be fitted into this block, obviously with new gaskets, shells, etc.
The discovery was in the garage again, and this time the engine was pulled out and disasembled on the engine stand. Big-end and main shells all looked really good for a 117K mile rover V8 - as did the pistons. All the piston skirts all measured up withing 2thou of each other (grade B pistons) and weren't scuffed or damaged - just very, very well carbon'd up on the crowns!
The Elrings I fitted 10K miles earlier had heavy gouges in the firing rings, just like the last gaskets, but liners were all still seated flush with the deck and top edges did not appear to be damaged or nicked on any of the matching cylinders.
I'm actually working on the discovery in 'slow-time' in amongst evertthing else I need to so, but it was a beautiful day here yesterday, and I was having a bit of a clear-up in the garage before doing more re-assembly work on the 'new' engine. I decided to have a play with the 'old' engine block that I was tripping over and have moved three times for no reason(!)
It was pressure-washed to remove excess oil and grime, then placed on top of my gas grill to slowly warm the block up. I wanted to see if I could get the liners to move by heating it up.
So, after 20 minutes on 'low' the engine block was at 85 degrees C according to my thermocouple contact probe. I put a gloved hand inside the first liner ready to see if I could perhaps pry it loose and it shocked me by lifting upwards as easily as a follower in a well-built engine. Next one did the same, and the next! I ran inside to grab the camera, took a few pics then lifted the engine off the grill and took some video.
http://www.youtube.com/watch?v=7fRDR5svIv8
http://www.youtube.com/watch?v=d6G1Ojv3I20
First video, block was at 85 degrees C - see how easily the liners move. The second video was a few minutes later, block had cooled to 71 degrees C - You can see I can easilly hold the block for several seconds showing it is not excessivly hot, yet I could still easily pull out and re-insert a liner upto 3/4 of it's installation depth by hand. In the end, five sleeves were easily removed. The ones that didn't budge were #1 #7 and #8.
I have every confidence that LandRover really made some mistakes with this engine by specifying a fit between the liners and bores that was not adequate. Any liner that I can spin around by hand when the block is at 'operating temperature' is going to move - and is not exactly going to be optimal in taking heat away from the cylinder... I don't know for sure, but I'd suspect that the 'Production norm' for installing liners in alloy blocks is to heat the block to something like 150degrees C, and slide the liners in - perhaps with a slight interference, such that there is no way that liner is moving in 'normal' operating temperatures...
One final thought though - do you think that LR purposely relaxed the interference because they were concerned that at -40, the alloy block could contract so much that the block would actually crack because the hoop-stresses around the iron sleeves because too high? We already know that blocks were selected for each engine type, based on their wall thickness (or scrapped if insufficient) so perhaps they intentionally chose this loose tolerance to avoid a different issue altogether....
So, has anyone else stuck their engine on the grill? Just think how much money you could save when doing top-hats, by supplying your engine shop a liner-less block... Just get it on the grill and it appears they come out pretty easily.
Now, I'm sure some nay-sayers will insist that this means I have five cracked bores which relaxed the interference and allowed the liners to move (despite the lack of water loss), so I will clean the bores this week and do a dye-penetrant check on them. For a bore to 'grow' 1 thou means I must have a crack that is 'approximately' 3.141592653589793238462643383279502884 thou - so I think it'll be easy to see with dye!
Final summary - If your engine ticks, look at your head gasket firing rings. Any grooves in them - and you have this same problem!
So, for those who haven't seen any of my previous posts, I'll start from the beginning. It's a little wordy - but that is me all over!
atriot: 2003 discovery purchased at 107k miles with a ticking engine. Spec of discovery was exactly what we were looking for - A dark grey SE7, black leather, no ACE, heated windsheild, DVD, 2003/4 model year. Discovery also was dealer serviced all its life. Purchased for a good price (because of ticking) from the dealer who had taken it on trade-in from previous (one) owner. Engine was quiet as a dead bird when cold, but sounded like a 1.5 (!) cylinder diesel was hiding inside the block somewhere when the engine was up to normal operating temperature!
We drove LR for just under 1000 miles before stripping down to replace what was believed (or hoped) to be a bad cam follower / camshaft. In that time:
The engine used no water.
The engine did not pressurise cooling system.
The exhaust gaskets were not leaking, SAI valves were not rattling; the noise was definately deep inside engine.
The engine ran smoothly, made good power, used no discernable oil in that time.
Shell Rotella swapped in at 107k miles, the day after the disco was delivered.
100 miles after first oil change, tried seafoam treatment; no difference at all.
The noise eventually became too much for the wife - she was concerned it meant immediate failure, and eventually it was pulled into the garage for work at 108K miles.
On disasembly, it didn't appear that the engine had ever been apart before. Factory thread-sealer still present, head bolts super-tight, factory harness snaps still present, OE landrover gaskets, OE plug wires, etc.
Cylinders / pistons were not steam-cleaned, confirming no head-gasket / water-jacket problems.
Top-end disassembled: camshaft, camshaft drive lifters, head gaskets changed, valves re-faced, stem seals changed, broken oil pump rotors changed, pump alignment fixed, pushrods checked for straightness/length, rockers disasembled and inspected (all perfect). Old camshaft and followers were in perfect condition, as was the parts that could be inspected (no sludge anywhere). Cam bearings were a little worn, but had zero measurable radial float - hence deemed fit for future use!
The old (original) head gaskets had heavy gouges in firing rings on block-side on the middle four cylinders; with VERY heavy gouges on two of the cylinders. These were same diameter as the tops of the liners, suggesting liners moving upwards. Had a pretty sure feeling that the block was bad (that well documented Rover V8 problem), but needed the vehicle fixed quicky.
So, the engine was re-assembled with new parts mentioned above, and new Elring head gaskets, and another fresh supply of Rotella with a genuine LR filter.
On startup, engine ticked again when warm - although not quite as badly as before. Drove almost 10K miles, and the tapping noise had become really bad; the only exception was a 4hr non-stop drive towing 7000lbs, with the engine occasionally labouring hard. Sometime in this trip, the ticking stopped. The Discovery went through 2 (cold-start) drive cycles the follwoing week - being perfectly quiet like it should be. Then, the ticking suddenly started again, and subsequently got worse than ever.
A replacement top-hat engine block was purchased from V8Developments in the UK. This was based on a block from a 1996 discovery, converted to Bosch crank sensor and fitted with new top-hat cylinder liners (sleeves). All parts from the 2003 engine will be fitted into this block, obviously with new gaskets, shells, etc.
The discovery was in the garage again, and this time the engine was pulled out and disasembled on the engine stand. Big-end and main shells all looked really good for a 117K mile rover V8 - as did the pistons. All the piston skirts all measured up withing 2thou of each other (grade B pistons) and weren't scuffed or damaged - just very, very well carbon'd up on the crowns!
The Elrings I fitted 10K miles earlier had heavy gouges in the firing rings, just like the last gaskets, but liners were all still seated flush with the deck and top edges did not appear to be damaged or nicked on any of the matching cylinders.
I'm actually working on the discovery in 'slow-time' in amongst evertthing else I need to so, but it was a beautiful day here yesterday, and I was having a bit of a clear-up in the garage before doing more re-assembly work on the 'new' engine. I decided to have a play with the 'old' engine block that I was tripping over and have moved three times for no reason(!)
It was pressure-washed to remove excess oil and grime, then placed on top of my gas grill to slowly warm the block up. I wanted to see if I could get the liners to move by heating it up.
So, after 20 minutes on 'low' the engine block was at 85 degrees C according to my thermocouple contact probe. I put a gloved hand inside the first liner ready to see if I could perhaps pry it loose and it shocked me by lifting upwards as easily as a follower in a well-built engine. Next one did the same, and the next! I ran inside to grab the camera, took a few pics then lifted the engine off the grill and took some video.
http://www.youtube.com/watch?v=7fRDR5svIv8
http://www.youtube.com/watch?v=d6G1Ojv3I20
First video, block was at 85 degrees C - see how easily the liners move. The second video was a few minutes later, block had cooled to 71 degrees C - You can see I can easilly hold the block for several seconds showing it is not excessivly hot, yet I could still easily pull out and re-insert a liner upto 3/4 of it's installation depth by hand. In the end, five sleeves were easily removed. The ones that didn't budge were #1 #7 and #8.
I have every confidence that LandRover really made some mistakes with this engine by specifying a fit between the liners and bores that was not adequate. Any liner that I can spin around by hand when the block is at 'operating temperature' is going to move - and is not exactly going to be optimal in taking heat away from the cylinder... I don't know for sure, but I'd suspect that the 'Production norm' for installing liners in alloy blocks is to heat the block to something like 150degrees C, and slide the liners in - perhaps with a slight interference, such that there is no way that liner is moving in 'normal' operating temperatures...
One final thought though - do you think that LR purposely relaxed the interference because they were concerned that at -40, the alloy block could contract so much that the block would actually crack because the hoop-stresses around the iron sleeves because too high? We already know that blocks were selected for each engine type, based on their wall thickness (or scrapped if insufficient) so perhaps they intentionally chose this loose tolerance to avoid a different issue altogether....
So, has anyone else stuck their engine on the grill? Just think how much money you could save when doing top-hats, by supplying your engine shop a liner-less block... Just get it on the grill and it appears they come out pretty easily.
Now, I'm sure some nay-sayers will insist that this means I have five cracked bores which relaxed the interference and allowed the liners to move (despite the lack of water loss), so I will clean the bores this week and do a dye-penetrant check on them. For a bore to 'grow' 1 thou means I must have a crack that is 'approximately' 3.141592653589793238462643383279502884 thou - so I think it'll be easy to see with dye!
Final summary - If your engine ticks, look at your head gasket firing rings. Any grooves in them - and you have this same problem!
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