Hi all,

I really appreciate the advice you guys post. Ive enjoyed being guided through disco ownership!

I have an issue and looking for some advice.

I have a 2004 discovery 2 and recently it was leaking slot of oil from behind the engine mount. I jacked up the engine, swung the mount away and saw a grub screw drilled into the block. I think the previous owner had tried to nestle a screw up to the cylinder liner to stop it slipping. Maybe..

Anyway I took it out, permatexed the hole reinstalled the grub screw (tightly) and the oil leak stopped.

I drove the car a few days later and low oil pressure light came on. I changed oil and filter and light and knocking noise wouldn't go away so I dropped oil pan to look for sludge in pickup line.

Everything looks clean but I found aluminum shards in bottom of pan. I realized where I tightened the screw it must have been to tight and it had Schreded the side of a piston. Best way to describe the shred is like a popsicle width from Bottom of piston to near the top.

I haven't reassembled and driven it since. I'd be really grateful for some advice.

Proper
-Can I replace the sleeve and one piston?
-do I need to replace all 8 sleeves and 8 pistons?

Improper
-could I back out the grub screw, use something like jb weld (steel stick) from the outside of the block and smear it so it spooges through up to the inner edge of the liner. Then reassemble everything? The liner itself does not look scored. The piston just has this popsicle gouge in it. I realize this is a Bodgy fix but the engine was rebuilt by the previous owner only 2 months ago (obviously not that well if there were grub screws through the block)!

Really appreciate you advice? Thanks

 

 

Here is a picture. You can see how the grub screw is through the liner and has shredded the piston on its downstroke. Ideally I'd like to be able to repair this one piston and liner from underneath...

 

Heres how I see it. If the last guys idea of a rebuild included sheet metal stews as liner pins, there's no telling what else he did or didn't do.

yes you can just replace one piston, and can probably avoid replacing the liner at all, and if you are meticulous this will probably be adequate IF, big IF, there's nothing else wonky when you get it apart.

You would be surprised at how many people "rebuild" their short blocks by simply buying new bearings and piston rings and throwing it all together without making a single measurement. Or how many people's idea of a rebuild is just top end gaskets, with or without head and valvetrain work.

Since it's definitely got an oiling issue that is probably due to aluminum shavings jammed in various places, you really should remove and rebuild from scratch. Reuse pistons that are in spec, cam if it's in spec, rods and crank are prob fine, etc. Def get the block cleaned to be sure all obstructions are gone, line honed, etc. Pressure test for cracks.

You might be better served by a Turner short block when it's all said and done, but either way you need to pull the motor and investigate so might as well be sure that what gets put back in is devoid of issues like this and will last a long time.

 

Thanks for the advice mate. The liner is screwed. I tried posting a picture. The grub screw was actually drilled through the liner so when the piston came down it shredded the side of the piston. With a hole through the liner im guessing its cactus.

Does anyone know if I can replace the liner and piston from underneath through the sump area? There is oil in the piston top so I'm sure that oil is leaking up the side of the bore now so the piston top is cactus and this probably explains the low oil pressure.

If I can get away with replacing liner and piston top from underneath it could be something for me to look at. I've read you can dismantle from underneath but not sure if you can reinstall.

 

See grub screw penetrating lining and shred where piston has come down and hit it

 

The block and sleeve are tapered, sleeve can only come out from the top

 

It seems to be rebuild time. I'm getting quotes of $8500 for short block coupled to my old valve train here in Utah. The guys were very knowledgable and stepped me through the itemization. It seemed very honest, the short block from turner (assembled) is just over $5500 landed.

The other option that I need to price up is removing the block. Getting the sleeve pressed out (thanks for confirming King Koopa) getting and engineering shop to tig the hole in the block. One new liner pressed in (non top hat). Reassembly with same parts but one new piston and rings.

I totally understand that this is not the proper way to do it and the cost will probably be more like $2000 if I do the work myself but given everything else in the engine is new I'm having trouble scrapping it and spending another $8500 (although l think it is actually an honest cost for what you get).

Thanks!!

 

Send your block to Q&E in Anaheim CA, $1500 for all 8 top hat liners installed.

 

X1 ............. if push comes to shove, and I sincerely hope not, the best is new pistons and rings with top hat liners and short block and any other new bit's you can stretch the budget to, like a new oil pump, water pump, front and rear crank oil seals, crankshaft pulley, main and big end shells etc. Good luck.