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Discussion Starter · #1 ·
I just dropped the pan on a 1999 LX that two mechanics insisted had thrown a rod. Found at least two rings and parts of a piston in the pan. The broken piston stopped in the up position, no apparent damage to wall. What are my chanced of no serious damage. The piston broke when the car was being started.
 

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I dont know what would have caused a piston to fail, just due to 'starting'. So i would suspect you will have to do a comprehensive rebuild on the engine. And get a valve job done by a decent machine shop for the engine head.
If it were a 1949 flathead Ford V8, I would assume a piston just decided to come apart - but with an Escort it might have taken a lot of detonation to have done that to a piston. And the other pistons might be ready to fracture.
 

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Discussion Starter · #3 ·
Are you suggesting this was a very high mileage engine? Except for being a little weak on hills as compared to another Escort (standard shift) the engine preformed as a 120,000 mile engine would be expected to. Is it possible that the piston had a flaw?
 

· Former Escort Owner
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Valve seats tend to cause piston damage, including the damage you're describing if the engine is run for a long time with a dropped valve seat. I'm not saying that a dropped valve seat is your problem, but I'd do what denisond3 suggested and check the head.

Casey
 

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Escort engines can go several hundred thousand miles - and pistons fragmenting has not been a failure that I can recall. (Not that I have read every posting!) But detonation can destroy a piston in 5 minutes (though usually it takes longer torture before they fail), and a dropped valve seat - if someone kept driving it - would certainly ruin one or more pistons. It smashes the piston top enough that there is no clearance between the wrist pin and the pin bores in the piston. Then the piston will begin to melt as it starts 'siezing' itself to the wrist pin. This is a source of more heat/stress than anything except detonation. In such a case, either the piston would fragment, or the con rod would break.

Its possible the piston had a flaw - but that also seems rare. I have rebuilt 3 2nd gen. Escort engines. They all needed piston rings (oil control rings at least), the ring grooves cleaned out, and the head milled. The highest mileage one had 200k miles on it. I had the cylinders honed only because I took it to the machine shop to get the water jacket cleaned out. In all 3 engines (all over 100k miles) the original pistons went back in. I probably didnt need the new crank/rod bearings, but heck - they were not expensive. New seals of course. On one of them I replaced the core plugs in the block.

Since your Escort is a 3rd gen, I believe it has a knock sensor. If that failed (or its connector came loose), the pistons could have begun to melt just driving from Denver up to the passes at 10,000 ft.

I would also recommend you check each con rod for still being 'unbent'. One of my Escorts had already dropped an inlet valve seat when I bought it. I may rebuild that engine some day; but to put the car back on the road, I got an engine from a JY car - and rebuilt it. The engine with the dropped valve seat had two pistons that were no longer easy to rotate on the wrist pin - and had battered tops, and piston rings that were jammed in the smashed ring grooves. I wouldnt have trusted the con rods either.

Sorry about the need to give you bad news.
 

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Discussion Starter · #7 ·
Just removed the cylinder head bolts, one of the bolts adjacent to the damaged piston is covered with what looks like exhaust residue. Am I correct that the block is cracked? This is the inside corner bolt for #4 cylinder.
 

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I would have to hold the bolt it in my hand to really know, but I havent heard of Escort blocks cracking. So I would guess it is the normal dirt/crud from the years of operating near a source of high pressure gases with soot in them. I have seen Escort head bolts that were still clean, a lot that were covered with dry crud, and a few that were soaked in oil.

I have yet to see or hear of a block that cracked near a head bolt.

One of the normal things to do when rebuilding an engine is to run a thread tap into each of the bolt holes in the block, blow out all dust. And of course you never re-use those head bolts.
 
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