Right, gents. I was going to wait until Saturday to do the compression tests, probably because I was frightened for the results.
Anyway, grown a pair tonight and in a gap in the rain decided to give it a go. Here are the results.
I used the heater plug hole.
Here is cylinder No1
440psi
The end of the heater plug was a little sooty in one part and grey over the rest. I rubbed it with my finger - too late to take a picture then!
But, I took pictures of the others! Here's heater plug No2
Here's the compression on cylinder No2
440psi
The heater and compression on No3
432psi (Tester had an extra elbow in it to get in behind air filter)
Finally No4
432psi approx Again with the extra elbow on the tester compared to cylinder 1 and 2.
I thought 300Tdi compression was in the region of 348psi so mine seem to be very high! Is that a problem? Gauge carped?
Do the heater plugs look as though they are getting too hot? I'm a bit nervous about that as the piston crown in cylinder No4 was melting when the engine knacked.
What do you all reckon?