Yeah you'll need a compression tester, you can pick them up from halfords for about 30quid IIRC, just a gauge that screws into the glow plug hole. Try clearing the water then starting first, if it still runs like a bag of shit, then I'd think about testing compression
http://www.halfords.com/webapp/wcs/store...&langId=-1
http://www.halfords.com/webapp/wcs/store...&langId=-1
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