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1972 250c Engine noise

3925 Views 13 Replies 6 Participants Last post by  agillot
Just purchased a 1972 250c, overall good shape, however engine makes a knocking sound. The previous owner said that a head job was done (doubt it), but could it be possible that the job was done incorrectly? Also, what could be the most probable cause for an engine to knock?

If so, is this particular engine hard to rebuilt?

1 - 2 of 14 Posts
Depends on what they consider a "head job". It's possible they had the head surfaced and a new gasket slapped on and called it good. If so then there is a good chance the head was machined below tolerance. This can cause all kinds of problems, one which could be a loose guide causing a "rattle" sound.
It's possible but don't jump to conclusions. Do some investigation first. Try to narrow down the noise. One way to check individual cylinders is to pull the spark plug wires one at a time while the engine is running to try to eliminate the noise. This is merely a quick test and is not completely definitive but it can be a starting point.
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