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Discussion Starter · #1 ·
So it seems like dropped valve seats are common. What about valve guides? I'm having problems that maybe a bad guide. Cyl 4 problems... oily spark plus, lean condition, maybe a vac leak.....

Anyone have any tips on how to change one out? This engine previously dropped the seats in 3 and 4 and got rebuilt. What's a good way to check these?

Oh, and does anyone know what causes this??? Is it the egr port near #3 and #4? I also read it has something todo with the timing chain breaking, which also happened on my car, but it was thousands of miles between both events.

thanks!
 

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A good start is to do a compression test. I use the kind of tester that screws into the spark plug hole, and I crank the engine about 6 times, per each cylinder Im checking. If one cylinder has low compression - indicates a problem.
I know the 94 Escort I bought with a dropped valve seat on #4, had also dropped enough bits into the combustion chamber, that the pistons on cyl #4 and cyl #2, were damaged. Visibly the tops were battered, and when I pulled them out of the block, both of them had the top compression ring caught in the ring groove (which had obviously happened when the bits of the valve seat had gotten between the engine head and the piston top at its edges), and were no longer 'free' to expand to the cylinder wall. Also the pistons were not 'free' on the wrist pin. I could rotate the piston by hand, but it would stay wherever I left it, relative to the wrist pin. I didnt re-use those pistons. I presume the stuck compression ring would result in a dramatically lower compression reading, though I didnt check it out, since I already had the head off.
I dont recall any posting on the feoa.net forums about problems with Escort valve guides. On the engine I fixed up that had high mileage on it, the machine shop knurled the insides of the exhaust valve guides; it was their idea, I didnt know anything was needed.
 
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