Tue Jul 17, 2012 7:30 pm
No compression would suggest one of the following
1- Valve guides worn or valve not closing fully
2- Valve stem seals, but less likely
3- piston has a hole in the top
4- piston ring broken or very worn
5- could also have a shagged coil pack on that cylinder which means no fuel getting burnt and that has lead to other problems.
Either way, it's a head off job more than likely to find the fault, which means about £150 of bits for a decent headgasket set and head bolts plus other things which it would be daft not to replace whilst it is in bits. This is assuming it is then worth fixing your engine
You could get another M50 donk for similar money. But if you're not mechanical then it'll cost you a few quid for someone to pull the old engine & box and swap over your gearbox and ancillaries.
You could probably do it in a day on your driveway if you got stuck in early on and everything swapped over without dramas